Process for preparing cyclopentanone and derivatives

Abstract

The invention relates to a process for preparing cyclopentanone from furfuryl alcohol and / or furfural, a product mixture obtained or obtainable by the process, and a reactor for preparing cyclopentanone from furfuryl alcohol and / or furfural. The process comprises providing a biphasic solvent system, wherein the solvent system comprises water and an organic solvent; adding furfuryl alcohol and / or furfural to the solvent system over a first time period; and contacting the furfuryl alcohol and / or furfural with hydrogen and a hydrogenation catalyst over the first time period, to convert at least a portion of the furfuryl alcohol and / or furfural into cyclopentanone.

Description

[0001] Process for Preparing Cyclopentanone and Derivatives

[0002] Related Applications

[0003] The present application claims priority from, and the benefit of EP 25160690.1 filed

[0004] 27 February 2025 (27.02.2025), the contents of which are incorporated herein by reference in their entirety.

[0005] Field of the Invention

[0006] The present invention relates to a process for preparing cyclopentanone from furfuryl alcohol and / or furfural, a product mixture obtained or obtainable by the process, a reactor for preparing cyclopentanone from furfuryl alcohol and / or furfural, and use of a solvent system to improve the conversion of furfuryl alcohol and / or furfural to cyclopentanone.

[0007] Background

[0008] Cyclopentanone is an important feedstock chemical. Cyclopentanone is used as a synthetic building block or precursors in a number of high value industries, such as in pharmaceutical, fragrance and flavour production. Cyclopentanone is also used as an intermediate in the production of agrochemicals, polymers, binder resins, adhesives and coatings, as well as an organic solvent in some processes.

[0009] Traditionally, cyclopentanone has been obtained from fossil-derived sources, however, in recent years, there has been research into the production of cyclopentanone from biological sources, such as biomass. This so called ‘bio-cyclopentanone’ facilitates the production of downstream products using these biological sources. In particular, bio-cyclopentanone is of interest as an intermediate for the production of sustainable aviation fuels (SAF) or for the production of bio-cyclopentane. Cyclopentane is typically obtained from fossil-derived sources, but bio-cyclopentanone provides a viable bio-based feedstock for cyclopentane production.

[0010] The preparation of bio-cyclopentanone typically proceeds by synthesis from furfuryl alcohol or the unreduced furfural precursor. Hronec et al. first described the preparation of cyclopentanone from furfural by reaction at 160 °C under a hydrogen pressure of 80 bar, using a Pt / C catalyst in water.

[0011] The synthesis of cyclopentanone from furfural or furfuryl alcohol has since been explored with a range of laboratory scale studies using different conditions (as summarised by Dutta et al.), however, many of these syntheses are not practical for commercial scale preparation of cyclopentanone and cyclopentane. For example, many known processes have relatively poor yields of cyclopentanone and / or poor selectivity for cyclopentanone compared to polymer side products. Known processes typically use low concentrations of furfural or furfuryl alcohol, to

[0012] WO-502116 008910770supress polymer side-product formation, and as a result have low productivity, requiring large volumes of solvent and / or catalyst to produce small quantities of cyclopentanone. Obtaining high purity cyclopentanone at commercial scale is not viable using these known methods.

[0013] There is a need for a large scale, highly productive and commercially viable synthesis of cyclopentanone and cyclopentane from bio-derived sources. The present invention is developed in view of these considerations.

[0014] Summary of the Invention

[0015] In general, the present invention provides a process for preparing cyclopentanone from furfuryl alcohol and / or furfural, using a biphasic solvent system. The use of a biphasic solvent system has been found to improve the yield and selectivity for cyclopentanone, while minimising polymerisation side reactions. These conditions also allow for the reduction of cyclopentanone to cyclopentanol to be closely controlled, providing excellent selectivity for cyclopentanone or cyclopentanol.

[0016] In a general aspect of the invention there is provided a process for preparing cyclopentanone from furfuryl alcohol and / or furfural, the process comprising:

[0017] providing a biphasic solvent system, wherein the solvent system comprises water and an organic solvent;

[0018] adding furfuryl alcohol and / or furfural to the solvent system;

[0019] contacting the furfuryl alcohol and / or furfural with hydrogen and a hydrogenation catalyst, to convert at least a portion of the furfuryl alcohol and / or furfural into cyclopentanone.

[0020] The invention also provides a process for preparing cyclopentanol from furfuryl alcohol and / or furfural. The cyclopentanol may be prepared by reducing the cyclopentanone produced by the method of the invention.

[0021] The invention also provides a process for preparing cyclopentane from furfuryl alcohol and / or furfural. The cyclopentane may be prepared by further reducing the cyclopentanone and / or cyclopentanol produced by the method of the invention.

[0022] Without wishing to be bound by theory, it is thought that in a biphasic solvent system the rearrangement of the furfuryl alcohol to 4-hydroxycyclopent-2-en-1-one occurs in the aqueous phase. As water is eliminated from 4-hydroxycyclopent-2-en-1-one, the cyclopentenone and cyclopentanone product move into the organic solvent system. The removal of the product from the water drives the equilibrium forward. It is thought that this may also help control the reduction of cyclopentanone to cyclopentanol, improving selectivity for both products.

[0023] The organic solvent also has good solubility for the poorly water-soluble poly furfuryl alcohol (PFA). Thus, where side reactions do start to form PFA (during rearrangement of the furfuryl

[0024] WO-502116 008910770alcohol to 4-Hydroxycyclopent-2-en-1-one) the polymer moves from the aqueous phase to the organic phase. By removing the polymer from the aqueous phase, this inhibits further polymerisation of the PFA, as the rearrangement step and thus source of new polymer units occurs in the aqueous phase. As a result, less polymer side product is formed and any polymer side product which does form has relatively short polymer chains.

[0025] Aside from the improved yield of cyclopentanone, the short polymer chains can remain in solution in the organic phase during the reaction. The polymer is then less likely to be deposited on the reaction vessel as a result of precipitation, which may occur when using a purely aqueous solvent system or where less soluble, high molecular weight polymers are formed. These deposits can be difficult to clean from the reaction vessel, meaning additional cleaning steps and solvents are required. The polymers can also coat catalyst particles, leading to coalescence of catalyst particles. This deactivates the catalyst, decreasing its efficacy and requiring more frequent replenishment. The present invention thus provides a cleaner reaction, which allows for re-use of the reaction vessel with minimal cleaning and minimal additional solvent use. It also avoids catalyst deactivation, allowing for a longer catalyst life and reduced catalyst use.

[0026] The present inventors have also identified that the gradual addition of furfuryl alcohol and / or furfural reactant into the solvent system during the reaction can improve the yield and selectivity for cyclopentanone, and reduce polymerisation side reactions.

[0027] Accordingly, the present invention provides a process for preparing cyclopentanone from furfuryl alcohol and / or furfural, by adding furfuryl alcohol and / or furfural to a solvent system over a first time period, and contacting the furfuryl alcohol and / or furfural with hydrogen and a hydrogenation catalyst over the first time period, to convert at least a portion of the furfuryl alcohol and / or furfural into cyclopentanone.

[0028] In some embodiments, the furfuryl alcohol and / or furfural are added gradually to the solvent system over the first time period. In some embodiments, the furfuryl alcohol and / or furfural to are added in multiple additions to the solvent system over the first time period.

[0029] The furfuryl alcohol and / or furfural may be maintained in the solvent system at a concentration of 20 wt.% or less, based on the total mass of furfuryl alcohol and / or furfural and the solvent system, during the first time period. In some embodiments, the furfuryl alcohol and / or furfural are maintained in the solvent system at a concentration of 10 wt.% or less during the first time period, such as 5 wt.% or less, such as 3 wt.% or less.

[0030] Typically, the maximum concentration of furfuryl alcohol and / or furfural in the solvent system during the first time period is Ai wt.%, based on the mass of furfuryl alcohol and / or furfural and the solvent system, during the first time period. The maximum concentration typically refers to the maximum instantaneous concentration of furfuryl alcohol and / or furfural at any point during the first time period. This may also be known as the peak concentration. In most

[0031] WO-502116 008910770cases, the maximum concentration of furfuryl alcohol and / or furfural will occur when furfuryl alcohol and / or furfural is added to the solvent system (especially when the furfuryl alcohol and / or furfural is added in a single addition). Following addition, the furfuryl alcohol and / or furfural is consumed as the reaction proceeds, and the concentration decreases.

[0032] In some embodiments, Ai is 20 wt.% or less, such as 10 wt.% or less, such as 5 wt.% or less, such as 3 wt.% or less, such as 2 wt.% or less, such as 1 wt.% or less.

[0033] In some embodiments, Ai is from 0.01 to 3 wt.%, such as from 0.1 to 2 wt.%, such as from 0.2 to 1 wt.%. In some embodiments, Ai is from 0.01 to 20 wt.%, such as from 0.1 to 5 wt.%, such as from 0.2 to 3 wt.%.

[0034] In some embodiments, the furfuryl alcohol and / or furfural are maintained in the solvent system at a concentration of 3 wt.% or less, based on the total mass of furfuryl alcohol and / or furfural and the solvent system, during the first time period.

[0035] The concentration of the furfuryl alcohol and / or furfural in the solvent system may be determined using any suitable method. The concentration of the furfuryl alcohol and / or furfural in the solvent system may be determined by infrared spectroscopy (e.g., FT-IR), nearinfrared spectroscopy (e.g., FT-NIR), gas chromatography (e.g., GC-MS) or liquid chromatography (e.g., HPLC).

[0036] The concentration of the furfuryl alcohol and / or furfural may be determined in situ. That is, the concentration of the furfuryl alcohol and / or furfural may be determined without interrupting the reaction. The concentration of the furfuryl alcohol and / or furfural may be determined using in situ infrared or near-infrared spectroscopy, such as FT-IR or FT-NIR.

[0037] The concentration of the furfuryl alcohol and / or furfural may be determined by sampling the reaction mixture. The reaction mixture may be sampled and the reaction quenched. The reaction may be quenched by, for example, cooling the reaction mixture, reducing reaction pressure and / or diluting the reaction mixture. The concentration of the furfuryl alcohol and / or furfural may be determined using gas chromatography or liquid chromatography (e.g., HPLC or GC-MS).

[0038] Typically, the total amount of furfuryl alcohol and / or furfural added to the solvent system over the first time period is A2 wt.%, based on the total mass of furfuryl alcohol and / or furfural and the solvent system. The total amount of furfuryl alcohol and / or furfural typically refers to all of the furfuryl alcohol and / or furfural added to the solvent system during the process.

[0039] In some embodiments, A2 is 3 wt.% or more, such as 5 wt.% or more, such as 10 wt.% or more, such as 20 wt.% or more, such as 30 wt.% or more, such as 40 wt.% or more.

[0040] WO-502116 008910770In some embodiments, A2 is from 3 to 90 wt.%, such as from 5 to 80 wt.%, such as from 10 to 70 wt.%, such as from 20 to 60 wt.%, such as from 30 to 55 wt.%, such as from 40 to

[0041] 50 wt.%.

[0042] When furfuryl alcohol and / or furfural are gradually added to the solvent system over the first time period, the maximum concentration of the furfuryl alcohol and / or furfural at any point during that first time period (A1) will be less than the total amount of furfuryl alcohol and / or furfural added over the first time period (A2). This is because the furfuryl alcohol and / or furfural are consumed by the reaction throughout the first time period.

[0043] The gradual addition of furfuryl alcohol and / or furfural may be quantified by Formula (I).

[0044] Typically, A1 and A2 satisfy the Formula (I):

[0045] A2 / AI = B (I)

[0046] wherein B is greater than 1.

[0047] In some embodiments, B is 2 or more, such as 5 or more, such as 10 or more, such as 20 or more, such as 30 or more. In some embodiments, B is from 2 to 1,000, such as from 5 to 500, such as from 10 to 100, such as from 20 to 50, such as from 30 to 40.

[0048] By way of illustration, if a total of 5 g of furfuryl alcohol and / or furfural is added to 95 g of solvent over the first time period, then A2 is 5 wt.%. If the maximum concentration of furfuryl alcohol and / or furfural in the solvent system during the first time period is 1 wt.% (e.g., because furfuryl alcohol and / or furfural is added as 5 x 1g aliquots), then A1 is 1 wt.% and B is 5.

[0049] The furfuryl alcohol and / or furfural may be added to the solvent system at an addition rate of from 0.1 to 20 wt.% / hour, such as 0.5 to 10 wt.% / hour, such as from 1 to 5 wt.% / hour, such as from 1.5 to 3 wt.% / hour, wherein the addition rate is based on the mass of furfuryl alcohol and / or furfural added as a percentage of the initial mass of the solvent system.

[0050] The concentration of furfuryl alcohol and / or furfural described above may be achieved using the addition rates described above.

[0051] The furfuryl alcohol and / or furfural may be maintained in the solvent system at a concentration of 20 wt.% or less, by using an addition rate of from 0.1 to 20 wt.% / hour, such as 0.5 to 10 wt.% / hour, such as from 1 to 5 wt.% / hour, such as from 1.5 to 3 wt.% / hour. In some embodiments, the furfuryl alcohol and / or furfural are maintained in the solvent system at a concentration of 10 wt.% or less during the first time period, such as 5 wt.% or less, such as 3 wt.% or less, by using an addition rate of from 0.5 to 10 wt.% / hour, such as from 1 to 5 wt.% / hour, such as from 1.5 to 3 wt.% / hour.

[0052] WO-502116 008910770Without wishing to be bound by theory, it is thought that by gradually adding the furfuryl alcohol and / or furfural to the solvent system in this way, the maximum concentration of furfuryl alcohol and / or furfural is kept low throughout the reaction. The low concentration reduces the propensity of the furfuryl alcohol and / or furfural to polymerise to PFA, and favours the rearrangement to 4-hydroxycyclopent-2-en-1-one and onwards reaction to cyclopentanone.

[0053] By gradually adding the furfuryl alcohol and / or furfural, a relatively large proportion of cyclopentanone can be prepared in a relatively small solvent volume, while avoiding a high instantaneous concentration of reactant. This is important where the process uses a biphasic solvent system including a non-aqueous solvent. In contrast, preparation of cyclopentanone using a low concentration of furfuryl alcohol and / or furfural, but without the gradual addition of more reactant, is unproductive in terms of cyclopentanone produced per volume of solvent. The gradual addition of furfuryl alcohol and / or furfural allows for the use of smaller volumes of solvent while still avoiding polymerisation side reactions. The process is therefore viable on larger commercial scales.

[0054] In an aspect of the invention there is provided a process for preparing cyclopentanone from furfuryl alcohol and / or furfural, the process comprising:

[0055] providing a biphasic solvent system, wherein the solvent system comprises water and an organic solvent;

[0056] adding furfuryl alcohol and / or furfural to the solvent system over a first time period; contacting the furfuryl alcohol and / or furfural with hydrogen and a hydrogenation catalyst over the first time period, to convert at least a portion of the furfuryl alcohol and / or furfural into cyclopentanone;

[0057] wherein the maximum concentration of furfuryl alcohol and / or furfural in the solvent system during the first time period is Ai wt.%, based on the mass of furfuryl alcohol and / or furfural and the solvent system, during the first time period;

[0058] wherein the total amount of furfuryl alcohol and / or furfural added to the solvent system over the first time period is A2 wt.%, based on the total mass of furfuryl alcohol and / or furfural and the solvent system; and

[0059] A1 and A2 satisfy the Formula (I):

[0060] A2 / AI = B (I)

[0061] wherein B is greater than 1.

[0062] In an aspect of the invention there is provided a process for preparing cyclopentanone from furfuryl alcohol and / or furfural, the process comprising:

[0063] providing a biphasic solvent system, wherein the solvent system comprises water and an organic solvent;

[0064] adding furfuryl alcohol and / or furfural to the solvent system over a first time period;

[0065] WO-502116 008910770contacting the furfuryl alcohol and / or furfural with hydrogen and a hydrogenation catalyst over the first time period, to convert at least a portion of the furfuryl alcohol and / or furfural into cyclopentanone;

[0066] wherein the furfuryl alcohol and / or furfural are maintained in the solvent system at a concentration of 3 wt.% or less, based on the total mass of furfuryl alcohol and / or furfural and the solvent system, during the first time period.

[0067] In a related aspect there is provided a process for preparing cyclopentanone from furfuryl alcohol and / or furfural, the process comprising:

[0068] providing a biphasic solvent system, wherein the solvent system comprises water and an organic solvent;

[0069] adding furfuryl alcohol and / or furfural to the solvent system over a first time period; contacting the furfuryl alcohol and / or furfural with hydrogen and a hydrogenation catalyst over the first time period, to convert at least a portion of the furfuryl alcohol and / or furfural into cyclopentanone;

[0070] wherein the furfuryl alcohol and / or furfural is added to the solvent system at an addition rate of from 0.5 to 10 wt.% / hour, such as from 1 to 5 wt.% / hour, such as from 1.5 to 3 wt.% / hour, wherein the average addition rate is based on the mass of furfuryl alcohol and / or furfural added as a percentage of the initial mass of the solvent system, during the first time period.

[0071] In some embodiments, the process further comprises contacting the furfuryl alcohol and / or furfural with hydrogen and a hydrogenation catalyst over a second time period, to convert at least a portion of the furfuryl alcohol and / or furfural into cyclopentanone;

[0072] wherein the second time period is after the first time period.

[0073] During the second time period, furfuryl alcohol and / or furfural may not be added to the solvent system.

[0074] In a second aspect of the invention there is provided a product mixture comprising cyclopentanone, wherein the product mixture is obtained or obtainable by the process of the first aspect.

[0075] In a third aspect of the invention there is provided a reactor for preparing cyclopentanone from furfuryl alcohol and / or furfural, the reactor comprising:

[0076] a reaction vessel for a solvent system, wherein the solvent system comprises water and an organic solvent;

[0077] a source of furfuryl alcohol and / or furfural, for adding furfuryl alcohol and / or furfural to the reaction vessel over a first time period,

[0078] wherein the reaction vessel is for contacting the furfuryl alcohol and / or furfural with hydrogen and a hydrogenation catalyst over the first time period, to convert at least a portion of the furfuryl alcohol and / or furfural into cyclopentanone; wherein the furfuryl alcohol and / or furfural is added to the solvent system at an addition rate of from 0.5 to 10 wt.% / hour, such as

[0079] WO-502116 008910770from 1 to 5 wt.% / hour, such as from 1.5 to 3 wt.% / hour, wherein the average addition rate is based on the mass of furfuryl alcohol and / or furfural added as a percentage of the initial mass of the solvent system.

[0080] In a related aspect of the invention there is provided a reactor for preparing cyclopentanone from furfuryl alcohol and / or furfural, the reactor comprising:

[0081] a reaction vessel for a solvent system, wherein the solvent system comprises water and an organic solvent;

[0082] a source of furfuryl alcohol and / or furfural, for adding furfuryl alcohol and / or furfural to the reaction vessel over a first time period,

[0083] wherein the reaction vessel is for contacting the furfuryl alcohol and / or furfural with hydrogen and a hydrogenation catalyst over the first time period, to convert at least a portion of the furfuryl alcohol and / or furfural into cyclopentanone; wherein the furfuryl alcohol and / or furfural are present in the solvent system at a concentration of 3 wt.% or less, based on the total mass of furfuryl alcohol and / or furfural and the solvent system, during the first time period.

[0084] In a fourth aspect of the invention there is provided a use of a biphasic solvent system comprising water and an organic solvent, to improve the conversion of furfuryl alcohol and / or furfural to cyclopentanone, such as to increase the yield of cyclopentanone to 50 wt.% or more, such as 60 wt.% or more, such as 70 wt.% or more.

[0085] In another aspect, there is provided a product mixture comprising cyclopentanone, wherein the product mixture comprises:

[0086] (i) 50 wt.% or more of cyclopentanone, such as 60 wt.% or more, such as 70 wt.% or more;

[0087] (ii) 10 wt.% or less of cyclopentanol, such as 7 wt.% or less, such as 4 wt.% or less; and / or

[0088] (iii) 40 wt.% or less of polyfurfuryl alcohol, such as 30 wt.% or less, such as 25 wt.% or less;

[0089] based on the total mass of reaction products in the product mixture.

[0090] In some embodiments of the product mixture, the total amount of cyclopentanone is 3 wt.% or more, based on the total mass of the reaction products and the solvent system, such as 5 wt.% or more, such as 20 wt.% or more, such as 30 wt.% or more, such as 40 wt.% or more.

[0091] There is also provided cyclopentanone obtained or obtainable by the process of the first aspect.

[0092] Another aspect of the invention is a process for preparing cyclopentanone from furfuryl alcohol and / or furfural, the process comprising:

[0093] WO-502116 008910770preparing cyclopentanone from furfuryl alcohol and / or furfural according to the process of the first aspect; and

[0094] contacting the cyclopentanone with hydrogen, a hydrogenation catalyst and an acid catalyst to convert at least a portion of the cyclopentanone into cyclopentane.

[0095] There is also provided cyclopentane obtained or obtainable by the process of the above aspect.

[0096] Further aspects of the invention are set out in the detailed description and examples.

[0097] Summary of the Figures

[0098] The present invention is described with reference to the figures listed below.

[0099] Figure 1 shows a GC trace of the product mixture obtained from Example 1B (upper phase, containing succinonitrile as internal standard, sample in acetonitrile).

[0100] Figure 2 shows a GC trace of product mixture obtained from Example 1B (lower phase, containing succinonitrile as internal standard, sample in acetonitrile).

[0101] Figure 3 shows a flow diagram of an example process of the invention.

[0102] Detailed Description of the Invention

[0103] The present invention provides a process for preparing cyclopentanone from furfuryl alcohol and / or furfural, using a biphasic solvent system.

[0104] There is provided a process for preparing cyclopentanone from furfuryl alcohol and / or furfural, the process comprising:

[0105] providing a biphasic solvent system, wherein the solvent system comprises water and an organic solvent;

[0106] adding furfuryl alcohol and / or furfural to the solvent system;

[0107] contacting the furfuryl alcohol and / or furfural with hydrogen and a hydrogenation catalyst, to convert at least a portion of the furfuryl alcohol and / or furfural into cyclopentanone.

[0108] In an aspect of the invention there is provided a process for preparing cyclopentanone from furfuryl alcohol and / or furfural, the process comprising:

[0109] providing a biphasic solvent system, wherein the solvent system comprises water and an organic solvent;

[0110] adding furfuryl alcohol and / or furfural to the solvent system over a first time period;

[0111] WO-502116 008910770contacting the furfuryl alcohol and / or furfural with hydrogen and a hydrogenation catalyst over the first time period, to convert at least a portion of the furfuryl alcohol and / or furfural into cyclopentanone.

[0112] The furfuryl alcohol and / or furfural may be maintained in the solvent system at a concentration of 20 wt.% or less, based on the total mass of furfuryl alcohol and / or furfural and the solvent system, during the first time period. In some embodiments, the furfuryl alcohol and / or furfural may be maintained in the solvent system at a concentration of 10 wt.% or less during the first time period, such as 5 wt.% or less, such as 3 wt.% or less. Preferably, the furfuryl alcohol and / or furfural are maintained in the solvent system at a concentration of 3 wt.% or less.

[0113] The furfuryl alcohol and / or furfural may be added to the solvent system at an addition rate of from 0.5 to 10 wt.% / hour, such as from 1 to 5 wt.% / hour, such as from 1.5 to 3 wt.% / hour, wherein the average addition rate is based on the mass of furfuryl alcohol and / or furfural added as a percentage of the initial mass of the solvent system.

[0114] Preferably, the maximum concentration of furfuryl alcohol and / or furfural in the solvent system during the first time period is Ai wt.%, based on the mass of furfuryl alcohol and / or furfural and the solvent system, during the first time period; wherein the total amount of furfuryl alcohol and / or furfural added to the solvent system over the first time period is A2 wt.%, based on the total mass of furfuryl alcohol and / or furfural and the solvent system; and

[0115] A1 and A2 satisfy the Formula (I):

[0116] A2 / AI = B (I)

[0117] wherein B is greater than 1.

[0118] Ordomsky etal. describes a biphasic solvent system for hydrogenation of furfural to cyclopentanone. In this document, 5g of furfural is reacted in 600ml of solvent - which gives a total concentration of furfural of about 0.8%. The furfural is added in one addition, and so the maximum concentration of furfural is also about 0.8%. Ordomsky et al. does not describe the gradual addition of furfural to the solvent system.

[0119] Dohade et al. describes a biphasic solvent system for conversion of furfural to cyclopentanone. In this document, 0.35g of furfural is used with 35ml of solvent, giving a total concentration of about 1%. The furfural is added in one addition, and so the maximum concentration of furfural is also about 1%. Dohade et al. does not describe the gradual addition of furfural to the solvent system. The document describes various approaches to improving the yield of cyclopentanone, but gradual addition of furfural is not described.

[0120] Hronec et al. describes the preparation of cyclopentanone from furfural in a 1-butanol and water solvent system. The furfural is present at about 5 wt.% and is not added gradually over

[0121] WO-502116 008910770- li¬

[0122] the first time period. The maximum concentration of furfural is the same as the total amount of furfural added.

[0123] CN 110183317 describes the preparation of cyclopentanone from furfuryl alcohol in n-hexane and water. 1g of furfuryl alcohol is present in 20ml of water and 20ml of hexane, giving a concentration of about 3%. In the document, furfuryl alcohol is added in one addition, so the maximum concentration of furfural is also about 3%.

[0124] These documents do not describe the gradual addition of furfural or furfuryl alcohol to the solvent system, such that the total amount of furfural or furfuryl alcohol added during a first time period is greater than the maximum concentration of furfural or furfuryl alcohol during the first time period.

[0125] Process

[0126] The process is for preparing cyclopentanone from furfuryl alcohol and / or furfural. The process is thought to occur via the following reaction scheme.

[0127]

[0128] In some embodiments the process is for preparing cyclopentanone (4) from furfural (8).

[0129] Preferably, the process is for preparing cyclopentanone (4) from furfuryl alcohol (1).

[0130] In an example embodiment, the process comprises:

[0131] providing a biphasic solvent system, wherein the solvent system comprises 1.5 volumes of water and 0.5 volumes of organic solvent;

[0132] adding 1 volume of furfuryl alcohol to the solvent system over from a first time period, wherein the first time period is from 24 to 72 hours;

[0133] contacting the furfuryl alcohol and / or furfural with hydrogen and a hydrogenation catalyst, such as Raney Nickel, over the first time period, at a temperature of 150 °C or more and a pressure of 8 bar or more, to convert at least a portion of the furfuryl alcohol and / or furfural into cyclopentanone;

[0134] continuing to contact the furfuryl alcohol and / or furfural with hydrogen and the hydrogenation catalyst, over a second time period, at a temperature of 150 °C or more and a pressure of 8 bar or more, to continue convert at least a portion of the furfuryl alcohol and / or furfural into cyclopentanone, wherein the second time period is from 5 to 30 hours.

[0135] WO-502116 008910770Solvent System

[0136] The process comprises a step of: providing a biphasic solvent system, wherein the solvent system comprises water and an organic solvent. This may be known as the ‘solvent system preparation’ step.

[0137] The solvent system is biphasic. A biphasic solvent is a solvent system that has two immiscible liquid phases. The solvent system is an aqueous biphasic solvent system. That is, the solvent system includes water and an organic solvent which is immiscible with water. The phases may be known as an aqueous phase and an organic phase.

[0138] It will be appreciated that some organic solvent may be miscible with water when present at very small concentrations. The biphasic solvent therefore includes sufficient organic solvent such that an organic phase is formed which is immiscible with the aqueous phase. The organic solvent is an organic solvent which forms a biphasic solvent with water, such as under the reaction conditions described herein.

[0139] Reactants in the process, such as furfuryl alcohol and / or furfural, and / or products of the process, such as cyclopentanone may have varying solubility with the aqueous phase, and so may be known to form a phase separate from the aqueous or organic phases. The organic phase is preferably formed from a solvent which is not a product or reactant of the process. Although the solvent may stabilise reactive species, such as intermediates, are typically not actively involved in the reaction.

[0140] The organic solvent may provide particular levels of solubility with certain reactants and products of the process. The extent of the solubility of a compound in a solvent may be defined as the concentration of solute in a saturated solution. A saturated solution is a solution in which no more solute can be dissolved. Where there is no solubility limit, the solvent and compound may be said to be miscible.

[0141] Solubility may be measured under ambient conditions (e.g., 1 atm and 20 °C). Solubility may be measured according to ISO 7579:2009.

[0142] The organic solvent may have a good solubility for cyclopentanone. In this way, the cyclopentanone product may be dissolved in the organic phase. This may drive the reaction forward.

[0143] In some embodiments, the organic solvent has a solubility for cyclopentanone of 30 wt.% or more, such as 40 wt.% or more, such as 50 wt.% or more, such as 60 wt.% or more, wherein solubility is determined under ambient conditions.

[0144] In some embodiments, the organic solvent is miscible with cyclopentanone. In some embodiments, the organic solvent has a solubility for cyclopentanone of 80 wt.% or less, such

[0145] WO-502116 008910770as 60 wt.% or less, such as 40 wt.% or less, wherein solubility is determined under ambient conditions.

[0146] In some embodiments, the organic solvent has a solubility for cyclopentanone of from

[0147] 30 to 100 wt.%, such as from 40 to 80 wt.%, such as from 50 to 70 wt.%, wherein solubility is determined under ambient conditions.

[0148] The organic solvent may have a good solubility for poly(furfuryl alcohol) (PFA). In particular, the organic solvent may have a good solubility for PFA having 10 or less repeating units, such as 8 or less repeating units, such as 5 or less repeating units, such as 3 or less repeating units, such as from 2 to 10 repeating units, such as from 4 to 8 repeating units, such as 5 to 7 repeating units. In this way, the PFA side product may be dissolved in the organic phase. This may prevent further reaction of PFA in the aqueous phase, and growth of the PFA.

[0149] Solubility for the PFA may be determined based on the PFA formed during the process, as described herein. Typically, the PFA has a number of repeating units as described above.

[0150] In some embodiments, the organic solvent has a solubility for PFA of 10 wt.% or more, such as 20 wt.% or more, such as 30 wt.% or more, such as 40 wt.% or more, wherein solubility is determined under ambient conditions.

[0151] In some embodiments, the organic solvent is miscible with PFA. In some embodiments, the organic solvent has a solubility for PFA of 80 wt.% or less, such as 60 wt.% or less, such as 40 wt.% or less, wherein solubility is determined under ambient conditions.

[0152] In some embodiments, the organic solvent has a solubility for PFA of from 10 to 100 wt.%, such as from 20 to 70 wt.%, such as from 30 to 50 wt.%, wherein solubility is determined under ambient conditions.

[0153] Optionally, the organic solvent may have a good solubility for cyclopentane. In some embodiments the organic solvent is miscible with cyclopentane.

[0154] The organic solvent is intended to remove short-chain polymers of PFA formed from the aqueous phase. The organic solvent may have a better solubility for PFA than water. In this way, the biphasic solvent system prevents further polymerisation of the PFA and consumption of the furfuryl alcohol in side reactions. This is thought to improve yield of the cyclopentanone product.

[0155] The solubility of components, such as cyclopentanone and PFA, in the organic solvent may be measured using any suitable method, such as ASTM D3827-92(2020). The solubility of the components may be determined under the reaction conditions used for the process described herein. The organic solvents described herein may provide the preferred solubility for cyclopentanone and / or PFA.

[0156] WO-502116 008910770In some embodiments, the organic solvent is a substituted or unsubstituted

[0157] C5-14 (hetero)arene, C5-10 (hetero)cycloalkane, C5-10 alkane, C2-10 heteroalkane or a combination thereof.

[0158] In some embodiments, the organic solvent is a substituted or unsubstituted C5-14 (hetero)arene, C5-10 (hetero)cycloalkane, or C2-10 heteroalkane.

[0159] In some embodiments, the organic solvent is a substituted or unsubstituted Ce-14 carboarene, C5-14 heteroarene or C5-10 (hetero)cycloalkane.

[0160] In some embodiments, the organic solvent is a substituted Ce-14 carboarene, C5-14 heteroarene or C5-10 (hetero)cycloalkane. In some embodiments, the organic solvent is a substituted Ce carboarene, C5 heterocycloalkane or Ce cycloalkane.

[0161] The compounds may be substituted with one or more C1-6 alkyl, C2-6 heteroalkyl, hydroxyl, or amino groups. The compounds may be substituted with one or two C1-6 alkyl, C2-6 heteroalkyl, hydroxyl, or amino groups.

[0162] The compounds may be substituted with a C1-6 alkyl group, such as a C1-3 alkyl group, such as a C1-2 alkyl group, such as a methyl group.

[0163] The compounds may be substituted with a C2-6 heteroalkyl group such as a C2-4 alkyl group, such as a C2-3 alkyl group, such as a hydroxymethyl group.

[0164] In some embodiments, the organic solvent is a substituted Ce-14 carboarene, C5-10 heterocycloalkane or C5-10 cycloalkane, wherein the substitution is C1-6 alkyl, C2-6 heteroalkyl, hydroxyl, or amino groups.

[0165] In some embodiments, the organic solvent is a substituted Ce-14 carboarene, C5-10 heterocycloalkane or C5-10 cycloalkane, wherein the substitution is one or more C1-6 alkyl groups.

[0166] In some embodiments, the organic solvent is a substituted Ce-14 carboarene, C5-10 heterocycloalkane or C5-10 cycloalkane, wherein the substitution is one or more C1-3 alkyl groups.

[0167] In some embodiments, the organic solvent is a substituted Ce-14 carboarene C5-10 heterocycloalkane or C5-10 cycloalkane, wherein the substitution is one or more C1-2 alkyl groups.

[0168] In some embodiments, the organic solvent is a substituted Ce-14 carboarene, C5-10 heterocycloalkane or C5-10 cycloalkane, wherein the substitution is one or more methyl groups.

[0169] WO-502116 008910770In some embodiments, the organic solvent is a substituted Ce-14 carboarene, C5-10 heterocycloalkane or C5-10 cycloalkane, wherein the substitution is one or two C1-6 alkyl groups.

[0170] In some embodiments, the organic solvent is a substituted Ce-14 carboarene, C5-10 heterocycloalkane or C5-10 cycloalkane, wherein the substitution is one or two C1-3 alkyl groups.

[0171] In some embodiments, the organic solvent is a substituted Ce-14 carboarene, C5-10 heterocycloalkane or C5-10 cycloalkane, wherein the substitution is one or two C1-2 alkyl groups.

[0172] In some embodiments, the organic solvent is a substituted Ce-14 carboarene, C5-10 heterocycloalkane or C5-10 cycloalkane, wherein the substitution is one or two methyl groups.

[0173] In some embodiments, the organic solvent is a substituted Ce carboarene, C5 heterocycloalkane or Ce cycloalkane, wherein the substitution is one or more C1-6 alkyl groups.

[0174] In some embodiments, the organic solvent is a substituted Ce carboarene, C5 heterocycloalkane or Ce cycloalkane, wherein the substitution is one or more C1-2 alkyl groups.

[0175] In some embodiments, the organic solvent is a substituted Ce carboarene, C5 heterocycloalkane or Ce cycloalkane, wherein the substitution is one or more methyl groups.

[0176] In some embodiments, the organic solvent is a substituted Ce carboarene, C5 heterocycloalkane or Ce cycloalkane, wherein the substitution is one or two C1-6 alkyl groups.

[0177] In some embodiments, the organic solvent is a substituted Ce carboarene, C5 heterocycloalkane or Ce cycloalkane, wherein the substitution is one or two C1-2 alkyl groups.

[0178] In some embodiments, the organic solvent is a substituted Ce carboarene, C5 heterocycloalkane or Ce cycloalkane, wherein the substitution is one or two methyl groups.

[0179] Preferably, the Ce carboarene is toluene or xylene.

[0180] Preferably the C5 heterocycloalkane is 2-methyl-THF.

[0181] Preferably the Ce cycloalkane is methylcyclohexane.

[0182] WO-502116 008910770Preferably, the organic solvent is a toluene, xylene, 2-methyl-THF, methylcyclohexane or a combination thereof.

[0183] Preferably, the organic solvent is a toluene, xylene, 2-methyl-THF or methylcyclohexane.

[0184] Preferably, the organic solvent is a toluene, xylene, 2-methyl-THF, methylcyclohexane or a combination of 2-methyl-THF and methylcyclohexane.

[0185] In particular, the organic solvent may be toluene or 2-methyl-THF.

[0186] Without wishing to be bound by theory, it is thought that certain cyclic solvents, such as Ce-14 carboarene, C5-14 heteroarene or C5-10 cycloalkane, provide improved selectivity for cyclopentanone. The cyclic solvents are able to stabilise a carbocation formed during the rearrangement of furfuryl alcohol to 4-hydroxycyclopent-2-en-1-one on route to the cyclopentanone product. The cyclic solvents stabilise the carbocation by donation of electrons above and below the ring. This may be observed with cyclohexane as well as aromatic TT electrons in toluene, xylene and 2-methyl-THF.

[0187] C5-10 (hetero)arene is an aromatic compound having from 5 to 14 atoms forming the arene ring or fused arene rings. For example, the arene compound may be a 5 membered arene compound, such as furan or thiophene, or a 6 membered arene compound, such as benzene or pyridine, or a 10 membered arylene compound, such as methylnaphthene or dimethylnaphthene.

[0188] C5-10 (hetero)arene may be a Ce- carboarene or a C5-10 heteroarene. A carboarene only includes carbon atoms in the ring. A heteroarene includes carbon atoms and at least one heteroatom in the ring.

[0189] Preferably C5-14 (hetero)arene is C5-10 (hetero)arylene, more preferably C5-10 heteroarene or Ce-w carboarene, even more preferably C5 heteroarene or Ce carboarylene.

[0190] Preferably, the heteroatom is oxygen. Thus, the C5 heteroarene is preferably substituted or unsubstituted furan.

[0191] C5-10 (hetero)cycloalkane is a saturated compound having from 5 to 10 atoms forming the (hetero)alkane ring. For example, the (hetero)cycloalkane compound may be a 5 membered cycloalkane compound, such as cyclopentane, or a 6 membered cycloalkane compound, such as cyclohexane, or a 10 membered cycloalkane compound, such as cyclodecane or decalin. For example, the (hetero)cycloalkane compound may be a 5 membered heterocycloalkane compound, such as THF, 2-methyl-THF, or N-methyl-pyrrolidine, or a 6 membered heterocycloalkane compound, such as oxane, dioxanem or thiane, or a 9 membered heterocycloalkane compound, such as oxonane.

[0192] WO-502116 008910770Preferably, C5-10 (hetero)cycloalkane is a Ce- cycloalkane, more preferably Ce cycloalkane.

[0193] Preferably, C5-10 (hetero)cycloalkane is a Ce- heterocycloalkane, more preferably C5 heterocycloalkane.

[0194] C5-10 alkane is a saturated compound having from 5 to 10 atoms forming the alkane chain. The alkane may be branched or straight. For example, the alkane compound may be a 5 membered alkane, such as n-pentane or iso pentane, the alkane may be a 6 membered alkane, such as n-hexane or iso-hexane, a 7 membered alkane, such as heptane, or an 8 membered alkane, such as octane or iso-octane.

[0195] C2-10 heteroalkane is a saturated compound having from 5 to 10 atoms forming the alkane chain, which includes at least one heteroatom. The heteroatom may be positioned at the terminus of the chain (e.g., primary position) or between carbon atoms (e.g., secondary or tertiary position). The which includes at least one heteroatom may be branched or straight. For example, the heteroalkane may be a 2 membered heteroalkane, such as methanol, a 3 membered heteroalkane, such as ethanol, a four-membered heteroalkane such as isopropyl alcohol or trimethylamine, a five membered heteroalkane, such as diethyl ether, or a seven membered heteroalkane, such as triethylamine.

[0196] The C5-14 arene, C5-10 cycloalkane, C5-9 heterocycloalkane, C5-10 alkane or C2-10 heteroalkane each may be substituted or unsubstituted.

[0197] In some embodiments, the organic solvent forms an azeotrope with water. The organic solvent and water forming an azeotrope with water allows for easier distillation of the products.

[0198] In some embodiments, the azeotrope formed from the organic solvent and water has a boiling point (at atmospheric pressure) of 50 °C or more, such as 60 °C or more, 70 °C or more, 80 °C or more, 90 °C or more. In some embodiments, the azeotrope formed from the organic solvent and water has a boiling point (at atmospheric pressure) of 200 °C or less, such as 180 °C or less, 160 °C or less, 140 °C or less, 120 °C or less. The boiling point may be taken to be a range formed from any combination of the upper and lower limits described above.

[0199] In some embodiments, the organic solvent has a boiling point (at atmospheric pressure) of 50 °C or more, such as 60 °C or more, 70 °C or more, 80 °C or more, 90 °C or more. In some embodiments, the organic solvent has a boiling point (at atmospheric pressure) of 200 °C or less, such as 180 °C or less, 160 °C or less, 140 °C or less, 120 °C or less. The boiling point may be taken to be a range formed from any combination of the upper and lower limits described above.

[0200] The mass ratio of water to organic solvent in the solvent system is typically such that a biphasic mixture may be formed. In some embodiments, the mass ratio of water to organic

[0201] WO-502116 008910770solvent in the solvent system is such that the cyclopentanone and / or PFA formed during the reaction may be dissolved in the organic solvent (as described above).

[0202] In some embodiments, the mass ratio of water to organic solvent in the solvent system is 1 or more, such as 2 or more, such as 3 or more. In some embodiments, the mass ratio of water to organic solvent in the solvent system is 6 or less, such as 5 or less, such as 3 or less. In some embodiments, the mass ratio of water to organic solvent in the solvent system is from 1 to 6, such as from 2 to 5, such as from 3 to 4. The mass ratio of water to organic solvent in the solvent system is typically about 3.

[0203] The ratio of water to organic solvent described refers to the initial solvent ratio prior to any reaction. This does not include any solvent which may be present in the furfuryl alcohol and / or furfural which is added to the solvent system during the addition step. It also does not typically include any water consumed or produced during the reaction.

[0204] In some embodiments, the biphasic solvent system may further comprise an additive.

[0205] The additive may be an acid or base. Preferably, the additive is a base. The base may be water soluble. Any suitable base may be used, such as a nitrogen base. Suitable nitrogen bases include triethanolamine. Alternatively, the base may be provided on a solid support. Suitable solid-supported bases include solid supported amines, such as ScavengePore™ phenylethyl-diethylamine.

[0206] Without wishing to be bound by theory, it is thought that the base may coordinate the intermediate furanic carbocation present during the Piancatelli rearrangement. It is thought that this may reduce polymerisation, by retaining the carbocation for sufficiently long to rearrange and be hydrogenated towards the cyclopentanone product, rather than undergoing side-reactions such as polymerisation.

[0207] Addition Step

[0208] The process comprises a step of: adding furfuryl alcohol and / or furfural to the solvent system over a first time period. This may be known as the ‘addition step’.

[0209] In some embodiments, furfuryl alcohol and / or furfural is added to the solvent system. In some embodiments furfural is added to the solvent system, and then may be reduced to form furfuryl alcohol as part of the process. Preferably, furfuryl alcohol is added to the solvent system.

[0210] The rate of addition of the furfuryl alcohol and / or furfural to the solvent system may be controlled such that the furfuryl alcohol and / or furfural are maintained below a certain concentration. The rate of addition of the furfuryl alcohol and / or furfural to the solvent system may be controlled such that the furfuryl alcohol and / or furfural are maintained between upper and lower limits of concentration.

[0211] WO-502116 008910770The concentration can be maintained by adding the furfuryl alcohol and / or furfural at a rate such that the furfuryl alcohol and / or furfural are consumed at a similar rate to their addition. In this way, a low concentration is maintained throughout the reaction, which reduces the propensity of the furfuryl alcohol and / or furfural to polymerise to PFA, and favours the rearrangement to 4-hydroxycyclopent-2-en-1-one and onwards reaction to cyclopentanone.

[0212] In some embodiments, the furfuryl alcohol and / or furfural are present in the solvent system at a concentration of 3 wt.% or less, such as 2 wt.% or less, such as 1 wt.% or less, during the first time period, based on the total mass of the furfuryl alcohol and / or furfural and the solvent system.

[0213] In some embodiments, the furfuryl alcohol and / or furfural are present in the solvent system at a concentration of from 0.01 to 3 wt.%, such as 0.1 to 2 wt.%, such as 0.2 to 1 wt.%, during the first time period, based on the total mass of the furfuryl alcohol and / or furfural and the solvent system.

[0214] In some embodiments, the furfuryl alcohol and / or furfural are present in the solvent system at a concentration of 3 vol.% or less, such as 2 vol.% or less, such as 1 vol.% or less, during the first time period, based on the total mass of the furfuryl alcohol and / or furfural and the solvent system.

[0215] In some embodiments, the furfuryl alcohol and / or furfural are present in the solvent system at a concentration of from 0.01 to 3 vol.%, such as 0.1 to 2 vol.%, such as 0.2 to 1 vol.%, during the first time period, based on the total mass of the furfuryl alcohol and / or furfural and the solvent system.

[0216] The concentration may be maintained at these levels by monitoring the concentration of furfuryl alcohol and / or furfural in the solvent system during the reaction. The rate of addition can then be adjusted to keep the concentration within the ranges described above.

[0217] Typically, the maximum concentration of furfuryl alcohol and / or furfural in the solvent system during the first time period is Ai, based on the amount of furfuryl alcohol and / or furfural and the solvent system, during the first time period.

[0218] Ai may be determined based on mass. In some embodiments, Ai is 20 wt.% or less, such as 5 wt.% or less, such as 3 wt.% or less, such as 2 wt.% or less, such as 1 wt.% or less. In some embodiments, Ai is from 0.01 to 3 wt.%, such as from 0.1 to 2 wt.%, such as from 0.2 to 1 wt.%. In some embodiments, Ai is from 0.01 to 20 wt.%, such as from 0.1 to 5 wt.%, such as from 0.2 to 3 wt.%.

[0219] Ai may be determined based on volume. In some embodiments, Ai is 20 vol.% or less, such as 5 vol.% or less, such as 3 vol.% or less, such as 2 vol.% or less, such as 1 vol.% or less.

[0220] WO-502116 008910770In some embodiments, Ai is from 0.01 to 3 vol.%, such as from 0.1 to 2 vol.%, such as from 0.2 to 1 vol.%. In some embodiments, Ai is from 0.01 to 20 vol.%, such as from 0.1 to 5 vol.%, such as from 0.2 to 3 vol.%.

[0221] Typically, the total amount of furfuryl alcohol and / or furfural added to the solvent system over the first time period is A2, based on the total amount of furfuryl alcohol and / or furfural and the solvent system. The total amount of furfuryl alcohol and / or furfural typically refers to all of the of furfuryl alcohol and / or furfural added to the solvent system during the process. This may include furfuryl alcohol and / or furfural added in a single addition, over multiple additions, or by continuous addition.

[0222] A2may be determined based on mass. In some embodiments, A2is 3 wt.% or more, such as 5 wt.% or more, such as 10 wt.% or more, such as 20 wt.% or more, such as 30 wt.% or more, such as 40 wt.% or more. In some embodiments, A2is from 3 to 90 wt.%, such as from 5 to 80 wt.%, such as from 10 to 70 wt.%, such as from 20 to 60 wt.%, such as from 30 to 55 wt.%, such as from 40 to 50 wt.%.

[0223] A2may be determined based on volume. In some embodiments, A2is 3 vol.% or more, such as 5 vol.% or more, such as 10 vol.% or more, such as 20 vol.% or more, such as 30 vol.% or more, such as 40 vol.% or more. In some embodiments, A2is from 3 to 90 vol.%, such as from 5 to 80 vol.%, such as from 10 to 70 vol.%, such as from 20 to 60 vol.%, such as from 30 to 55 vol.%, such as from 40 to 50 vol.%.

[0224] Ai and A2may satisfy the Formula (I):

[0225] A2 / AI = B (I)

[0226] wherein B is greater than 1.

[0227] In some embodiments, B is 1.1 or more, such as 1.5 or more, such as 2 or more, such as 5 or more, such as 10 or more, such as 20 or more, such as 30 or more. In some embodiments, B is from 2 to 1 ,000, such as from 5 to 500, such as from 10 to 100, such as from 20 to 50, such as from 30 to 40.

[0228] In some embodiments, the addition step further comprises:

[0229] measuring the concentration of furfuryl alcohol and / or furfural in the solvent system; comparing the measured concentration to a target concentration; and

[0230] adjusting the rate of addition of the furfuryl alcohol and / or furfural in response to the comparison.

[0231] Measuring the concentration of furfuryl alcohol and / or furfural in the solvent system may be carried out using any suitable means, such as GC and HPLC. Suitable methods for of measuring the concentration of furfuryl alcohol and / or furfural in the solvent system are

[0232] WO-502116 008910770described in the examples section. The measurement may be carried out continuously throughout the reaction, or at intervals.

[0233] Comparing the measured concentration to a target concentration may be carried out by a numerical comparison. The target concentration may be preset. The target concentration may be a range or a value, preferably the target concentration is a range.

[0234] Adjusting the rate of addition of the furfuryl alcohol and / or furfural in response to the comparison may be carried out autonomously. Typically, where the measured concentration is not at the target concentration, the rate of addition of furfuryl alcohol and / or furfural is adjusted so as to bring the measured concentration towards the target concentration. Thus, where the measured concentration is higher than the target concentration, the addition rate may be reduced. Where the measured concentration is lower than the target concentration, the addition rate may be increased.

[0235] In some embodiments, the concentration of the furfuryl alcohol and / or furfural may not be measured. In such embodiments, the reaction may still be controlled by using a certain addition rate which has been found to provide good yield and selectivity for cyclopentanone.

[0236] In some embodiments the furfuryl alcohol and / or furfural is added to the solvent system at an addition rate of 10 wt.% / hour or less, such as 5 wt.% / hour or less, such as 3 wt.% / hour or less, wherein the addition rate is based on the mass of furfuryl alcohol and / or furfural added as a percentage of the initial mass of the solvent system.

[0237] In some embodiments the furfuryl alcohol and / or furfural is added to the solvent system at an addition rate of from 0.5 to 10 wt.% / hour, such as from 1 to 5 wt.% / hour, such as from 1.5 to 3 wt.% / hour, wherein the addition rate is based on the mass of furfuryl alcohol and / or furfural added as a percentage of the initial mass of the solvent system.

[0238] In specific examples, the furfuryl alcohol is added at a rate of from 1.70 wt.% / hour to 2.17 wt.% / hour.

[0239] In some embodiments the furfuryl alcohol and / or furfural is added to the solvent system at an addition rate of 10 vol.% / hour or less, such as 5 vol.% / hour or less, such as 3 vol.% / hour or less, wherein the addition rate is based on the mass of furfuryl alcohol and / or furfural added as a percentage of the initial mass of the solvent system.

[0240] In some embodiments the furfuryl alcohol and / or furfural is added to the solvent system at an addition rate of from 0.5 to 10 vol.% / hour, such as from 1 to 5 vol.% / hour, such as from 1.5 to 3 vol.% / hour, wherein the addition rate is based on the mass of furfuryl alcohol and / or furfural added as a percentage of the initial mass of the solvent system.

[0241] WO-502116 008910770In some embodiments, the total amount of furfuryl alcohol and / or furfural added to the solvent system over the first time period is from 5 to 80 wt.%, such as 20 to 70 wt.%, such as from 30 to 60 wt.%, such as 40 to 55 wt.% based on the mass of furfuryl alcohol and / or furfural added as a percentage of the initial mass of the solvent system.

[0242] In specific examples, the total amount of furfuryl alcohol and / or furfural added over the first time period is 54 wt.%.

[0243] In some embodiments, the total amount of furfuryl alcohol and / or furfural added to the solvent system over the first time period is from 10 to 80 vol.%, such as 30 to 70 vol.%, such as from 40 to 60 vol.%, based on the mass of furfuryl alcohol and / or furfural added as a percentage of the initial mass of the solvent system.

[0244] The gradual addition of the furfuryl alcohol and / or furfural allows for such high amounts of furfuryl alcohol and / or furfural to be added to a small system. This allows for the process to be carried out with excellent productivity, with minimal solvent use.

[0245] The addition of the furfuryl alcohol and / or furfural may be linear or non-linear. Preferably, the addition of the furfuryl alcohol and / or furfural is linear.

[0246] The addition of the furfuryl alcohol and / or furfural may be linear. That is, the furfuryl alcohol and / or furfural is added at the same rate throughout the first time period.

[0247] The addition of the furfuryl alcohol and / or furfural may be non-linear. That is, the furfuryl alcohol and / or furfural is added at a changing rate throughout the first time period. For example, the furfuryl alcohol and / or furfural may be added at an increasing or decreasing rate throughout the first time period. Preferably, the furfuryl alcohol and / or furfural is added at a decreasing rate throughout the first time period.

[0248] The addition of the furfuryl alcohol and / or furfural may be continuous or discontinuous.

[0249] Preferably, the addition of the furfuryl alcohol and / or furfural is continuous.

[0250] The addition of the furfuryl alcohol and / or furfural may be continuous. That is, the furfuryl alcohol and / or furfural is added continuously throughout the first time period. This may be achieved using a pump, such as a syringe pump.

[0251] The addition of the furfuryl alcohol and / or furfural may be discontinuous. That is, the furfuryl alcohol and / or furfural is added in discrete portions throughout the first time period. For example, the furfuryl alcohol and / or furfural may be added as a portion every sub-period of the first time period. The sub-period may be 10 minutes to 3 hours, such as 30 minutes to 1 hour. In other words, a portion of the furfuryl alcohol and / or furfural may be added every 1 hour.

[0252] WO-502116 008910770As described herein, the addition rate may be the average addition rate. For example, the addition rate may be the average addition rate over the first time period. The average addition rate may be calculated as the mean average of the addition rate over the first time period.

[0253] The furfuryl alcohol and / or furfural may be added in solution. When added in solution, the furfuryl alcohol and / or furfural are typically added in an aqueous solution. For example, the furfuryl alcohol and / or furfural may be added in an solution at a concentration of from 5 to 80 wt.%, such as from 10 to 50 wt.%, such as from 20 to 40 wt.%. The use of a solution to add the furfuryl alcohol and / or furfural allows for a more controlled addition over longer time periods, as a greater total volume is dispensed per unit time.

[0254] Preferably, furfuryl alcohol and / or furfural are added directly to the solvent system. That is, the furfuryl alcohol and / or furfural are preferably not in solution. By not providing the furfuryl alcohol and / or furfural in solution this improves the productivity of the reaction, as less solvent is used during the reaction process.

[0255] The addition step may use a semi-batch reactor. The semi-batch reactor allows for reactant to be added to the reaction vessel containing the solvent system during the reaction. The reactor is described in more detail below.

[0256] Contacting Step

[0257] The process comprises a step of: contacting the furfuryl alcohol and / or furfural with hydrogen and a hydrogenation catalyst over a first time period, to convert at least a portion of the furfuryl alcohol and / or furfural into cyclopentanone. This may be known as the ‘contacting step’.

[0258] The contacting step contacts the furfuryl alcohol and / or furfural added to the solvent system in the addition step with a hydrogenation catalyst and hydrogen. The contacting step also typically contacts the furfuryl alcohol and / or furfural added to the solvent system in the addition step with water. The contacting of these components together allows for the reaction of furfuryl alcohol and / or furfural to cyclopentanone.

[0259] The furfuryl alcohol and / or furfural may be contacted with further reaction components, or may be contacted with a hydrogenation catalyst and hydrogen in the presence of additional components, as described in more detail below.

[0260] Typically, the conversion of furfuryl alcohol and / or furfural into cyclopentanone comprises: optionally the hydrogenation of furfural to furfuryl alcohol;

[0261] the rearrangement of furfuryl alcohol to 4-hydroxycyclopent-2-en-1-one; and

[0262] the hydrogenation of 4-hydroxycyclopent-2-en-1-one to cyclopentanone.

[0263] WO-502116 008910770In other words, the conversion of furfuryl alcohol and / or furfural into cyclopentanone may proceed by:

[0264] optionally the hydrogenation of furfural to furfuryl alcohol;

[0265] the rearrangement of furfuryl alcohol to 4-hydroxycyclopent-2-en-1-one; and

[0266] the hydrogenation of 4-hydroxycyclopent-2-en-1-one to cyclopentanone.

[0267] The reaction is described in more detail in the examples section. The inventors have identified these intermediate products, as set out in the examples section. It is thought that when the conversion of furfural to cyclopentanone proceeds via this route this results in excellent selectivity for cyclopentanone and supresses side reactions.

[0268] Typically, the addition step and the contacting step are carried out simultaneously during the first time period. In this way, as the furfuryl alcohol and / or furfural are added to the solvent system the furfuryl alcohol and / or furfural are simultaneously contacted with the hydrogen and hydrogenation catalyst.

[0269] In general, the first time period is long enough that the furfuryl alcohol and / or furfural can be added gradually, and within the limits described for the addition step above, but not so long that the cyclopentanone product is over reduced to cyclopentanol. In some embodiments, the first time period is from 1 to 72 hours, such as from 6 to 54 hours, such as from 12 to 48 hours, such as from 24 to 36 hours.

[0270] In some embodiments, the cyclopentanone may be intentionally converted to cyclopentanol. In such embodiments, the reaction time is chosen so as to reduce the cyclopentanone to cyclopentanol. The cyclopentanol is prepared via the cyclopentanone as an intermediate. Therefore, a process which prepares cyclopentanol using the process described herein will produce cyclopentanone as an intermediate.

[0271] The first time period may be determined by measuring the concentration of the reaction components, such as the concentration of furfuryl alcohol and / or furfural. Thus, the first time period may be adjusted depending on the concentration of furfuryl alcohol and / or furfural in the solvent system.

[0272] In some embodiments, the process further comprises contacting the furfuryl alcohol and / or furfural with hydrogen and a hydrogenation catalyst over a second time period, to convert at least a portion of the furfuryl alcohol and / or furfural into cyclopentanone. Typically, the second time period is after the first time period. Typically, furfuryl alcohol and / or furfural are not added to the solvent system over the second time period.

[0273] In this way, addition of the furfuryl alcohol and / or furfural occurs over the first time period, but then stops in the second time period. The furfuryl alcohol and / or furfural continue to be contacted with the hydrogen and hydrogenation catalyst to allow for conversion into cyclopentanone. Providing this second time period allows for any unreacted furfuryl alcohol

[0274] WO-502116 008910770and / or furfural present at the end of the first time period to be converted to cyclopentanone, thus improving the yield of cyclopentanone.

[0275] The second time period is typically shorter than the first time period. Typically, the first time period is 2 to 5 times longer than the second time period.

[0276] Generally, the second time period should be long enough to allow the furfuryl alcohol and / or furfural to be converted to cyclopentanone, but not so long that the cyclopentanone product is over reduced to cyclopentanol. In some embodiments, the second time period is from 1 to 24 hours, such as from 3 to 15 hours, such as 5 to 10 hours.

[0277] In some embodiments, the first time period is from 1 to 60 hours, such as from 6 to 54 hours, such as from 12 to 48 hours, such as from 24 to 36 hours; and the second time period is from 1 to 24 hours, such as from 3 to 15 hours, such as 5 to 10 hours.

[0278] The second time period may be determined by measuring the concentration of the reaction components, such as the concentration of furfuryl alcohol and / or furfural. Thus, the second time period may be adjusted depending on the concentration of furfuryl alcohol and / or furfural in the solvent system.

[0279] In some examples, the first time period is from 25 hours to 32 hours, and the second time period is from 6 to 13 hours. In some examples the first time period is 25 hours and the second time period is 6 hours. In the examples the first time period is 32 hours and the second time period is 13 hours.

[0280] The contacting step results in the conversion of at least a portion of the furfuryl alcohol and / or furfural into cyclopentanone. The process of the invention results in excellent conversion to cyclopentanone.

[0281] In some embodiments, the second time period can be chosen to allow the furfuryl alcohol and / or furfural to be converted to a product comprising a greater concentration of cyclopentanone compared to cyclopentanol, on a wt% basis.

[0282] In some embodiments, the contacting step converts furfuryl alcohol and / or furfural into 50 wt.% or more of cyclopentanone, such as 60 wt.% or more, such as 70 wt.% or more. That is, the conversion of furfuryl alcohol and / or furfural into cyclopentanone is 50 wt.% or more, such as 60 wt.% or more, such as 70 wt.% or more.

[0283] The contacting step may also produce side products in addition to cyclopentanone, such as cyclopentanol and poly(furfuryl alcohol).

[0284] In some embodiments, the contacting step converts furfuryl alcohol and / or furfural into 20 wt% or less of cyclopentanol, such as 15 wt% or less. In some embodiments, the

[0285] WO-502116 008910770contacting step converts furfuryl alcohol and / or furfural into 10 wt.% or less of cyclopentanol, such as 7 wt.% or less, such as 4 wt.% or less. That is, the conversion rate of furfuryl alcohol and / or furfural into cyclopentanol is 10 wt.% or less, such as 7 wt.% or less, such as 4 wt.% or less.

[0286] In some embodiments, the second time period can be chosen to allow the furfuryl alcohol and / or furfural to be converted to a product comprising a greater concentration of cyclopentanol compared to cyclopentanone on a wt% basis. In some embodiments, the second time period is at least 12 hours, such as at least 24 hours, and the combination of the first time period and the second time period should be at least 60 hours, such as at least 70 hours.

[0287] In some embodiments, the combined total of the first time period and the second time period is long enough to allow the furfuryl alcohol and / or furfural to be converted to a product comprising a greater concentration of cyclopentanol compared to cyclopentanone on a wt% basis, such as a combined total of the first time period and the second time period of at least 60 hours, such as at least 70 hours, such as at least 80 hours, such as at least 90 hours.

[0288] In some embodiments, the contacting step converts furfuryl alcohol and / or furfural into 10 wt.% or more of cyclopentanol, such as 15 wt.% or more, such as 20 wt.% or more.

[0289] In some embodiments, the contacting step converts furfuryl alcohol and / or furfural into 50 wt.% or more of cyclopentanol, such as 60 wt.% or more, such as 70 wt.% or more. That is, the conversion of furfuryl alcohol and / or furfural into cyclopentanol is 50 wt.% or more, such as 60 wt.% or more, such as 70 wt.% or more.

[0290] In some embodiments, the contacting step may produce cyclopentanone and cyclopentanol as the primary products, that is the two products from the contacting step which are produced in the largest quantities in terms of wt% are cyclopentanone and cyclopentanol. In some embodiments, the contacting step may produce cyclopentanol as the primary product, that is the product from the contacting step which is produced in the largest quantity in terms of wt% is cyclopentanol.

[0291] In some embodiments, the contacting step converts furfuryl alcohol and / or furfural into 40 wt.% or less of poly(furfuryl alcohol), such as 30 wt.% or less, such as 25 wt.% or less. That is, the conversion of furfuryl alcohol and / or furfural into poly(furfuryl alcohol) is 40 wt.% or less, such as 30 wt.% or less, such as 25 wt.% or less.

[0292] Reaction Conditions

[0293] The contacting step allows the reaction components to interact and undergo a chemical reaction. The reaction components include furfuryl alcohol and / or furfural, hydrogen and a hydrogenation catalyst. The reaction components may also include, for example, acids, bases, buffers, and / or additional catalysts.

[0294] WO-502116 008910770The reaction components may be added to the solvent system before the addition step and / or the contacting step. The reaction components may be added to the solvent system before the addition step and the contacting step.

[0295] Preferably, the additional reaction components are added during the solvent preparation step. Thus, the solvent system preparation step may also include the provision of additional reaction components in the solvent system. The additional reaction components may be provided in the solvent system and / or in the headspace above the solvent system.

[0296] Hydrogen may be added to the head space of the solvent system. Hydrogen may be added to the head space of the solvent system before the addition step. Typically a stream of hydrogen is applied to the head space. This may be supplied using any suitable means, such as a hydrogen line. In this way, the reaction occurs in the presence of an excess of hydrogen.

[0297] Prior to addition of the hydrogen, the head space of the solvent system may be inerted (i.e., made inert). That is, the head space may be purged of oxygen. The head space may be inerted using any suitable means. For example, the head space may be inerted by adding and removing nitrogen gas. The nitrogen gas may be added / removed 3 or more times, such as 3 to 5 times. This acts to remove the oxygen from the head space.

[0298] Hydrogen may be added to the head space at elevated pressure. For example, hydrogen may be added at a partial pressure of 1 bar or more, such as 2 bar or more, such as 3 bar or more. Typically, hydrogen is added at a partial pressure of 1 to 5 bar, such as 2 to 3 bar. The pressure in the headspace includes the hydrogen partial pressure and the solvent partial pressure.

[0299] The hydrogenation catalyst may be added to the solvent system. The hydrogenation catalyst may be added to the solvent system before the addition step.

[0300] Any suitable hydrogenation catalyst may be used. Various hydrogenation catalysts are known for the conversion of furfuryl alcohol and / or furfural into cyclopentanone, for example as described in Dutta et al., Ordomsky et al. and Hronec et al., the contents of which are incorporated by reference.

[0301] The hydrogenation catalyst may be a transition metal catalyst. The hydrogenation catalyst may be a group 8 to 11 transition metal catalyst, such as a group 9 or 10 transition metal catalyst, such as group 10 transition metal catalyst.

[0302] The hydrogenation catalyst may be a nickel, platinum, palladium, ruthenium, copper or cobalt catalyst. Preferably, the hydrogenation catalyst is a nickel, platinum, palladium, ruthenium or

[0303] WO-502116 008910770copper catalyst. More preferably, the hydrogenation catalyst is a nickel, platinum or palladium catalyst.

[0304] The hydrogenation catalyst may be a bimetallic catalyst. The bimetallic catalyst may include any suitable combination of transition metals, such as nickel, platinum, palladium, ruthenium, copper or cobalt. The hydrogenation catalyst may be a bimetallic catalyst, such as Ni-Co catalyst, a Pt-Ru catalyst, or a Ni-Cu catalyst.

[0305] The hydrogenation catalyst may be provided on a substrate or scaffold. For example, the hydrogenation catalyst may be a transition metal on a carbon substrate, such as a Pd / C or a Ru / C catalyst.

[0306] In some embodiments, the hydrogenation catalyst is a nickel, platinum or palladium catalyst, such as a Raney Nickel catalyst. Preferably, the hydrogenation catalyst is a nickel catalyst, more preferably a Raney nickel catalyst.

[0307] The amount of catalyst used typically depends on the total amount of furfuryl alcohol and / or furfural. Any suitable mass ratio may be used.

[0308] The mass ratio of catalyst to furfuryl alcohol and / or furfural may be 0.005 or more, such as 0.008 or more, such as 0.01 or more, such as 0.1 or more. The mass ratio of catalyst to furfuryl alcohol and / or furfural may be 0.05 or less, such as 0.04 or less, such as 0.03 or less. For example, the mass ratio of catalyst to furfuryl alcohol and / or furfural may be from 0.005 to 0.05, such as from 0.008 to 0.04, such as from 0.01 to 0.03. The mass ratio is based on the total mass of catalyst to the total mass of furfuryl alcohol and / or furfural used in the process (i.e., the total mass of furfuryl alcohol and / or furfural added during the addition step).

[0309] The contacting step may take place in the presence of an acid, a base or a buffer. The acid, base or buffer may be added to the solvent system. The acid, base or buffer may be added to the solvent system before the addition step.

[0310] Any suitable acid, base or buffer may be used to provide the desired pH of the solvent system.

[0311] Typically the solvent system is acidic. That is, the pH of the solvent system is typically less than 7. The pH of the solvent system may be from 3 to 6, such as from 4 to 5. It has been found that an acidic solvent system improves selectivity for cyclopentanone.

[0312] Any suitable buffer may be used, such as KH2PO4 or K2HPO4. Any suitable acid may be used, such as acetic acid. Any suitable base may be used, such as sodium hydroxide.

[0313] The contacting step is typically carried out at elevated temperature. By extension, the addition step also occurs at elevated temperature. The temperature used for the first time

[0314] WO-502116 008910770period may be the same or different to the second time period. Preferably, the temperature used for the first time period is the same as for the second time period.

[0315] It has been found that carrying out the reaction at elevated temperatures and pressures, as described here, results in excellent selectivity for cyclopentanone.

[0316] The contacting step may be carried out at a temperature of 100 °C or more, such as 120 °C or more, 140 °C or more, 160 °C or more, or 180 °C or more. The contacting step may be carried out at a temperature of 220 °C or less, such as 200 °C or less, 190 °C or less, 180 °C or less, or 170 °C or less.

[0317] The contacting step may be carried out at a temperature of from 100 °C to 220 °C, such as from 120 °C to 210 °C, from 140 °C to 200 °C, from 150 °C to 190 °C, or from 160 °C to 180 °C. Preferably, the contacting step is carried out at about 150 to about 170 °C, such as about 160 °C.

[0318] The contacting step is typically carried out at elevated pressure. By extension, the addition step also occurs at elevated pressure. The pressure used for the first time period may be the same or different to the second time period. Preferably, the pressure sued for the first time period is the same as for the second time period.

[0319] The contacting step may be carried out at a pressure of 5 bar or more, such as 6 bar or more, such as 7 bar or more, such as 8 bar or more, such as 10 bar or more. The contacting step may be carried out at a pressure of 30 bar or less, such as 20 bar or less, such as 16 bar or less, such as 15 bar or less, such as 12 bar or less. The contacting step may be carried out at a pressure of from 5 to 30 bar, such as from 6 to 20 bar, such as from 7 to 16 bar, such as from 8 to 15 bar, such as from 10 to 12 bar.

[0320] The pressure may include contributions from a hydrogen partial pressure and a solvent vapour partial pressure. The solvent vapour partial pressure is typically larger than the hydrogen partial pressure. As described above, the hydrogen partial pressure is typically from 1 to 3 bar, such as from 1 to 2 bar. The remained of the pressure is provided by the solvent vapour.

[0321] Any combination of the temperature and pressures described above may be used. In particular, the contacting step may be carried out at:

[0322] (i) a temperature of 100 °C or more, such as from 140 °C to 200 °C, such as from 160 °C to 180 °C; and

[0323] (ii) a pressure of from 6 to 20 bar, such as from 8 to 15 bar, such as from 10 to 12 bar. Separation Step

[0324] The process may further comprise a step of separating the cyclopentanone from the solvent system. This may be known as the ‘separation’ step.

[0325] WO-502116 008910770The separation may be carried out using any suitable means. Typically, the separation is carried out by distillation.

[0326] The separation step may separate the cyclopentanone from the solvent system, and optionally other products of the reaction. For example, the separation step may separate the cyclopentanone from cyclopentanol and / or poly(furfuryl alcohol).

[0327] The separation step may be carried out on an aqueous phase and an organic phase separately. Alternatively, the separation step may be carried out on a combined organic phase and aqueous phase.

[0328] The separation step may include multiple steps. The first separation step may comprise separation of the biphasic solvent system to provide an azeotropic solvent mixture. The second separation step may comprise separation of the azeotropic solvent mixture.

[0329] The first step may comprise distillation at atmospheric pressure.

[0330] The second step may comprise distillation at elevated pressure. The second step may comprise Dean-Stark distillation. The Dean-Stark distillation may be carried out with cyclopentane. This results in the removal of water from the azeotropic solvent mixture. Furfural to Furfuryl Alcohol

[0331] The process is for preparing cyclopentanone from furfural and / or furfuryl alcohol. In some embodiments the process is for preparing cyclopentanone from furfural. Preferably, the process is for preparing cyclopentanone from furfuryl alcohol.

[0332] The furfuryl alcohol may be prepared from furfural. The furfuryl alcohol may be prepared from furfural in the same reaction or in a separate reaction. Preferably, furfuryl alcohol is prepared from furfural in a separate reaction.

[0333] Thus, the process may comprise a step of:

[0334] contacting furfural with hydrogen and a hydrogenation catalyst to convert at least a portion of the furfural into furfuryl alcohol.

[0335] The resulting furfuryl alcohol may then be used in the addition step.

[0336] The furfuryl alcohol and / or furfural may be purified prior to the addition step. The furfuryl alcohol and / or furfural may be purified by any suitable means, such as by distillation.

[0337] The furfuryl alcohol and / or furfural used in the process may be bio-based. As a consequence, the cyclopentanone produced by the process may be bio-based. The cyclopentane may also be bio-based.

[0338] WO-502116 008910770For example, the furfuryl alcohol and / or furfural produced from the digestion (e.g., acid digestion) of biomass. The digestion process typically involves the hydrolysis and dehydrogenation of biomass to produce furfural. The furfural may be reduced to give furfuryl alcohol. The biomass may comprise cellulose, such as hemi-cellulose. The biomass may be obtained from any suitable biological feedstock, such as corn cobs or sugarcane bagasse.

[0339] The modern carbon content of a substance can be used to determine if it is of bio-based. Modern carbon content may be determined by any suitable means, such as ASTM D6866 or EN 16575.

[0340] In some embodiments the furfuryl alcohol and / or furfural have a modern carbon content of 50 wt.% or more, such as 90 wt.% or more, such as 99 wt.% or more.

[0341] In some embodiments the cyclopentanone has a modern carbon content of 50 wt.% or more, such as 90 wt.% or more, such as 99 wt.% or more.

[0342] In some embodiments the cyclopentane has a modern carbon content of 50 wt.% or more, such as 90 wt.% or more, such as 99 wt.% or more.

[0343] Cyclopentanone to Cyclopentane

[0344] The cyclopentanone prepared by the process may be reduced to cyclopentane. The process is thought to occur via the following reaction scheme.

[0345]

[0346] In some embodiments the process is for preparing cyclopentane from furfural. Preferably, the process is for preparing cyclopentane from furfuryl alcohol. The cyclopentane may be prepared by the onwards reaction of cyclopentanone and / or cyclopentanol, as described herein. The cyclopentane may be prepared by the onwards reaction of cyclopentanone. The description of the preparation of cyclopentanone applies to the preparation of cyclopentane also.

[0347] Thus, the process of the first aspect may further comprise a step of:

[0348] contacting cyclopentanone and / or cyclopentanol with hydrogen, a hydrogenation catalyst and an acid catalyst to convert at least a portion of the cyclopentanone and / or cyclopentanol into cyclopentane.

[0349] WO-502116 008910770The invention may also relate to a process for preparing cyclopentanone from furfuryl alcohol and / or furfural, the process comprising:

[0350] preparing cyclopentanone from furfuryl alcohol and / or furfural according to the process of the first aspect; and

[0351] contacting the cyclopentanone with hydrogen, a hydrogenation catalyst and an acid catalyst to convert at least a portion of the cyclopentanone into cyclopentane.

[0352] The conversion of cyclopentanone to cyclopentane may occur in the same process as the preparation of cyclopentanone from furfuryl alcohol and / or furfural. That is, the step of contacting cyclopentanone with hydrogen, a hydrogenation catalyst and an acid catalyst may occur simultaneously or sequentially with the step of contacting furfuryl alcohol and / or furfural with hydrogen and a hydrogenation catalyst. The conversion of cyclopentanone to cyclopentane may occur in the same reaction vessel. Conversion of cyclopentanone to cyclopentane may occur using the same hydrogen source and hydrogenation catalyst. The conversion of cyclopentanone to cyclopentane may occur without work-up, separation and / or purification of the cyclopentanone.

[0353] Alternatively, the conversion of cyclopentanone to cyclopentane may occur after the preparation of cyclopentanone from furfuryl alcohol and / or furfural. That is, the step of contacting cyclopentanone with hydrogen, a hydrogenation catalyst and an acid catalyst may occur in a separate step to the step of contacting furfuryl alcohol and / or furfural with hydrogen and a hydrogenation catalyst. The conversion of cyclopentanone to cyclopentane may occur in a different reaction vessel. The conversion of cyclopentanone to cyclopentane may occur after the work-up, separation and / or purification of the cyclopentanone.

[0354] The conversion of cyclopentanone to cyclopentane may be carried out using the conditions described above, for the preparation of cyclopentanone from furfuryl alcohol and / or furfural. Further preferences for the conditions of the conversion of cyclopentanone to cyclopentane are described herein.

[0355] Any suitable hydrogenation catalyst may be used, as described above. A zeolite catalyst may be used, such as ZSM-5 zeolite. The ZSM-5 zeolite may be a H-ZSM-5 zeolite. The ZSM-5, such as the H-ZSM-5 may have a silicon to alumninim ratio (SAR) of about 80. Preferably a mixture of zeolite and transition metal catalyst is used. More preferably a mixture of zeolite and group 10 transition metal catalyst is used, such as a mixture of zeolite and Raney nickel.

[0356] The mass ratio of catalyst to cyclopentanone may be from 0.005 to 0.1 , such as from 0.008 to 0.08, such as from 0.01 to 0.06. Preferably, the mass ratio of catalyst to cyclopentanone is from 0.03 to 0.07, such as about 0.05.

[0357] The zeolite and Raney nickel may be present in a mass ratio of 1:1 to 3:1, such as about 2:1.

[0358] WO-502116 008910770Any suitable acid catalyst may be used. The acid catalyst aids dehydration of the cyclopentanol to cyclopentene. The acid catalyst may be any suitable hydrogen ion source. For example, the catalyst may be sulfuric acid, hydrochloric acid, phosphoric acid. The acid catalyst may be a solid acid catalyst such as a zeolite. In some cases, the acid catalyst may be the same as the hydrogenation catalyst, for example where the catalyst is a zeolite. A zeolite catalyst may be used, such as ZSM-5 zeolite.

[0359] The mass ratio of acid catalyst to cyclopentanone may be from 0.005 to 0.05, such as from 0.008 to 0.04, such as from 0.01 to 0.03.

[0360] The conversion cyclopentanone to cyclopentane may be carried out at a temperature of 100 °C or more, such as 120 °C or more, 140 °C or more, 160 °C or more, or 180 °C or more. The step may be carried out at a temperature of 240 °C or less, such as 220 °C or less, 200 °C or less, 190 °C or less, or 180 °C or less.

[0361] The conversion cyclopentanone to cyclopentane be carried out at a temperature of from 100 °C to 240 °C, such as from 120 °C to 220 °C, from 140 °C to 200 °C, from 160 °C to 190 °C, or from 170 °C to 180 °C. Preferably, the step is carried out at about 170 to about 180 °C, such as about 175 °C.

[0362] It is thought that carrying out the conversion cyclopentanone to cyclopentane at higher temperatures reduces side product formation. Typically, the conversion of cyclopentanone to cyclopentane is carried out at a higher temperature than the preparation of cyclopentanone from furfuryl alcohol and / or furfural.

[0363] The conversion cyclopentanone to cyclopentane may be carried out at a pressure of 10 bar or more, such as 15 bar or more, such as 20 bar or more, such as 25 bar or more, such as 30 bar or more. The contacting step may be carried out at a pressure of 40 bar or less, such as 35 bar or less, such as 30 bar or less. The conversion cyclopentanone to cyclopentane may be carried out at a pressure of from 10 to 50 bar, such as from 20 to 40 bar, such as from 25 to 35 bar, such as from 27 to 33 bar, such as about 30 bar.

[0364] The pressure may include contributions from a hydrogen partial pressure and a cyclopentanone vapour partial pressure. The hydrogen vapour partial pressure is typically larger than the cyclopentanone partial pressure. The pressure may be controlled using a hydrogen line, for example by setting a hydrogen line to the desired pressure.

[0365] The conversion cyclopentanone to cyclopentane may be carried out on non-solvated cyclopentanone. That is, an additional solvent is typically not present.

[0366] The reaction may be carried out (i.e. , heated as elevated pressure) for from 1 to 60 hours, such as from 6 to 54 hours, such as from 12 to 48 hours, such as from 20 to 30 hours.

[0367] Typically, the reaction is carried out for 24 hours.

[0368] WO-502116 008910770The cyclopentane may be produced at high yield, such that no separation step is required. For example, the cyclopentane may be produced at a conversion of 90 wt.% or more, such as 95 wt.% or more. The catalyst may be separated by any suitable methods, such as filtering.

[0369] Product Mixture

[0370] The process of the first aspect produces a product mixture. The product mixture typically refers to the product prior to separation. Thus, the product mixture may include cyclopentanone and other side products from the reaction, such as cyclopentanol and poly(furfuryl alcohol). The product mixture may also include unreacted furfuryl alcohol and / or furfural.

[0371] The process of the present invention results in excellent conversion of furfuryl alcohol and / or furfural to cyclopentanone and excellent selectivity for cyclopentanone. As a result, the product mixture includes high proportion of cyclopentanone and a low proportion of cyclopentanol and poly(furfuryl alcohol). Preferably, the conversion to cyclopentanone is greater than cyclopentanol and poly(furfuryl alcohol).

[0372] Accordingly, a second aspect of the invention provides to a product mixture comprising cyclopentanone, wherein the product mixture is obtained or obtainable by the process of the first aspect.

[0373] The product mixture may be defined by the conversion of furfuryl alcohol and / or furfural to cyclopentanone. The conversion is calculated as a yield, where 100 wt.% represents a theoretical complete conversion of furfuryl alcohol and / or furfural to cyclopentanone.

[0374] In some embodiments, 50 wt.% or more of the furfuryl alcohol and / or furfural is converted into cyclopentanone, such as 60 wt.% or more, such as 70 wt.% or more. In some embodiments, from 50 wt.% to 90 wt.% of the furfuryl alcohol and / or furfural is converted into cyclopentanone, such as from 60 wt.% to 80 wt.%, such as from 70 wt.% to 80 wt.%.

[0375] The product mixture may be characterised by the conversion of furfuryl alcohol and / or furfural to cyclopentanol. The conversion is calculated as a yield, where 100 wt.% represents a theoretical complete conversion of furfuryl alcohol and / or furfural to cyclopentanol.

[0376] In some embodiments, 10 wt.% or less of the furfuryl alcohol and / or furfural is converted into cyclopentanol, such as 7 wt.% or less, such as 4 wt.% or less. In some embodiments, from 0.1 wt.% to 10 wt.% of the furfuryl alcohol and / or furfural is converted into cyclopentanol, such as from 1 wt.% to 7 wt.%, such as from 2 wt.% to 4 wt.%.

[0377] WO-502116 008910770The product mixture may be characterised by the conversion of furfuryl alcohol and / or furfural to poly(furfuryl alcohol). The conversion is calculated as a yield, where 100 wt.% represents a theoretical complete conversion of furfuryl alcohol and / or furfural to poly(furfuryl alcohol).

[0378] In some embodiments, 40 wt.% or less of the furfuryl alcohol and / or furfural is converted into poly(furfuryl alcohol), such as 30 wt.% or less, such as 25 wt.% or less. In some embodiments, from 1 wt.% to 40 wt.% of the furfuryl alcohol and / or furfural is converted into poly(furfuryl alcohol), such as from 10 wt.% to 30 wt.%, such as from 20 wt.% to 25 wt.%.

[0379] In some embodiments, the product mixture may comprise:

[0380] 50 wt.% or more of cyclopentanone, such as 60 wt.% or more, such as 70 wt.% or more;

[0381] 10 wt.% or less of cyclopentanol, such as 7 wt.% or less, such as 4 wt.% or less; and 40 wt.% or less of polyfurfuryl alcohol, such as 30 wt.% or less, such as 25 wt.% or less.

[0382] In some embodiments of the product mixture, the total amount of cyclopentanone is 3 wt.% or more, based on the total mass of the reaction products and the solvent system, such as 5 wt.% or more, such as 20 wt.% or more, such as 30 wt.% or more, such as 40 wt.% or more.

[0383] The present invention also provides cyclopentanone obtained or obtainable by the process of the first aspect.

[0384] The furfuryl alcohol and / or furfural used in the process may be bio-based. As a consequence, the cyclopentanone obtained by the process may also be bio-based. The cyclopentane may also be bio-based. The modern carbon content of a substance can be used to determine if it is of bio-based. Modern carbon content may be determined by any suitable means, such as ASTM D6866 or EN 16575.

[0385] In some embodiments the cyclopentanone has a modern carbon content of 50 wt.% or more, such as 90 wt.% or more, such as 99 wt.% or more.

[0386] The present invention also provides cyclopentane obtained or obtainable by the process of the first aspect. The present invention provides an efficient synthetic route to bio-based cyclopentane.

[0387] The cyclopentane obtained by the process may be bio-based. In some embodiments the cyclopentane has a modern carbon content of 50 wt.% or more, such as 90 wt.% or more, such as 99 wt.% or more.

[0388] WO-502116 008910770Reactor

[0389] The process of preparing cyclopentanone from furfuryl alcohol and / or furfural may be carried out in any suitable reactor. The reactor may be operable to provide the reaction conditions described above, in relation to the process. The description of the process also applies to the reactor, where applicable.

[0390] The reactor typically comprises a reaction vessel and a source of reactant. The reactor may be a semi-batch reactor. The reactor may be a semi-flow reactor. These types of reactor typically include an inlet to allow for the addition of furfuryl alcohol and / or furfural throughout the reaction.

[0391] The reaction vessel is for a solvent system, wherein the solvent system comprises water and an organic solvent. The solvent system is as described for the process. The reaction vessel is made of a suitable material to receive the solvent system.

[0392] The source of reactant is a source of furfuryl alcohol and / or furfural. The source is for adding furfuryl alcohol and / or furfural to the reaction vessel over a first time period. The source of furfuryl alcohol and / or furfural is operable to control the rate of addition and / or concentration of the furfuryl alcohol and / or furfural.

[0393] For example, the source of furfuryl alcohol and / or furfural is operable to concentration of 3 wt.% or less, based on the total mass of furfuryl alcohol and / or furfural and the solvent system, during the first time period. In addition or alternatively, the source of furfuryl alcohol and / or furfural is operable to add the furfuryl alcohol and / or furfural at an addition rate of from 0.5 to 10 wt.% / hour, such as from 1 to 5 wt.% / hour, such as from 1.5 to 3 wt.% / hour, wherein the average addition rate is based on the mass of furfuryl alcohol and / or furfural added as a percentage of the initial mass of the solvent system.

[0394] The reactor may further comprise a gas line, such as hydrogen line, to provide a stream of hydrogen. The gas line is for providing a pressure to the reaction vessel, so as to pressurise the reaction vessel as required for the process. The pressure is as described for the process.

[0395] The reactor may further comprise a heater. The heater may be thermostatically controlled. The heater is for providing heat to the reaction vessel, so as to heat the reaction vessel as required for the process.

[0396] In particular, there is provided a reactor for preparing cyclopentanone from furfuryl alcohol and / or furfural, the reactor comprising:

[0397] a reaction vessel for a solvent system, wherein the solvent system comprises water and an organic solvent;

[0398] a source of furfuryl alcohol and / or furfural, for adding furfuryl alcohol and / or furfural to the reaction vessel over a first time period,

[0399] WO-502116 008910770wherein the reaction vessel is for contacting the furfuryl alcohol and / or furfural with hydrogen and a hydrogenation catalyst over the first time period, to convert at least a portion of the furfuryl alcohol and / or furfural into cyclopentanone; wherein the furfuryl alcohol and / or furfural are present in the solvent system at a concentration of 3 wt.% or less, based on the total mass of furfuryl alcohol and / or furfural and the solvent system, during the first time period.

[0400] In particular, there is provided a reactor for preparing cyclopentanone from furfuryl alcohol and / or furfural, the reactor comprising:

[0401] a reaction vessel for a solvent system, wherein the solvent system comprises water and an organic solvent;

[0402] a source of furfuryl alcohol and / or furfural, for adding furfuryl alcohol and / or furfural to the reaction vessel over a first time period,

[0403] wherein the reaction vessel is for contacting the furfuryl alcohol and / or furfural with hydrogen and a hydrogenation catalyst over the first time period, to convert at least a portion of the furfuryl alcohol and / or furfural into cyclopentanone; wherein the furfuryl alcohol and / or furfural are added at an addition rate of from 0.5 to 10 wt.% / hour, such as from 1 to 5 wt.% / hour, such as from 1.5 to 3 wt.% / hour, wherein the average addition rate is based on the mass of furfuryl alcohol and / or furfural added as a percentage of the initial mass of the solvent system.

[0404] Use and Applications

[0405] The process of the invention results in excellent conversion of furfuryl alcohol and / or furfural to cyclopentanone. The selectivity for cyclopentanone in the process is excellent.

[0406] As explained herein, this is thought to be achieved by using a biphasic solvent system.

[0407] Accordingly, the present invention provides a use of a biphasic solvent system comprising water and an organic solvent, to improve the conversion of furfuryl alcohol and / or furfural to cyclopentanone.

[0408] The present inventors have also found that the gradual addition of furfuryl alcohol and / or furfural to a solvent system has improved the conversion to cyclopentanone. This is achieved by adding the furfuryl alcohol and / or furfural at an addition rate of from 0.5 to 10 wt.% / hour, such as from 1 to 5 wt.% / hour, such as from 1.5 to 3 wt.% / hour. In addition or alternatively, this may be achieved by maintaining the solvent system at a concentration of 3 wt.% or less.

[0409] Accordingly, the present invention also provides a use of the addition rate of furfuryl alcohol and / or furfural to a solvent system to improve the conversion of furfuryl alcohol and / or furfural to cyclopentanone, wherein the addition rate of furfuryl alcohol and / or furfural is from 0.5 to 10 wt.% / hour, such as from 1 to 5 wt.% / hour, such as from 1.5 to 3 wt.% / hour; and / or wherein the concentration of furfuryl alcohol and / or furfural is maintained at 3 wt.% or less.

[0410] WO-502116 008910770Improving the conversion may include increasing the yield of cyclopentanone to 50 wt.% or more, such as 60 wt.% or more, such as 70 wt.% or more.

[0411] Improving the conversion may include reducing the yield of poly furfuryl alcohol to 40 wt.% or less, such as 30 wt.% or less, such as 25 wt.% or less.

[0412] Improving the conversion may include reducing the yield of cyclopentanol to 10 wt.% or less, such as 7 wt.% or less, such as 4 wt.% or less.

[0413] The cyclopentanone obtained or obtainable by the process of the present invention may find various applications.

[0414] The invention provides use of cyclopentanone obtained or obtainable by the process of the first aspect as a synthetic feedstock or precursor.

[0415] In some embodiments, the use is as a precursor for a pharmaceutical compound, a fragrance compound, a flavour compound, an agrochemical compound, a polymer, a binder resin, an adhesive and or a coating compound.

[0416] In some embodiments, the use is as a precursor for a pharmaceutical compound, a fragrance compound or a flavour compound.

[0417] In some embodiments, the use is as a precursor for a fuel. The use may be as a precursor for a fuel additive. The fuel may be an aviation fuel or a road fuel (e.g., gasoline or diesel). The fuel may be a sustainable aviation fuel (SAF) or a sustainable road fuel (e.g., sustainable gasoline or diesel).

[0418] The invention provides use of cyclopentanone obtained or obtainable by the process of the first aspect as an organic solvent.

[0419] The cyclopentane obtained or obtainable by the process of the present invention may also find various applications.

[0420] The invention provides use of cyclopentane obtained or obtainable by the process of the invention as a synthetic feedstock or precursor. In some embodiments the cyclopentane may be used as a precursor for a fuel, such as an aviation fuel, such as a sustainable aviation fuel (SAF).

[0421] The invention provides use of cyclopentane obtained or obtainable by the process of the invention as a coolant. The invention provides use of cyclopentane obtained or obtainable by the process of the invention as an insulator. The cyclopentane may be used as an insulator for a cooled body, such as a refrigerator. The cyclopentane may be used as a blowing agent

[0422] WO-502116 008910770for a refrigerator. The cyclopentane may be used as a blowing agent for a refrigerator in combination with a foam insulator, such as a polyurethane foam insulation.

[0423] The invention provides use of cyclopentane obtained or obtainable by the process of the first aspect as an organic solvent.

[0424] Other Preferences

[0425] Ambient conditions refer to a temperature of 20 °C and 1 atm of pressure, unless otherwise specified or apparent from the context.

[0426] Pressure refers to a gauge pressure (bar(g)) where the external pressure is 1 atm, unless otherwise specified or apparent from the context.

[0427] Each and every compatible combination of the embodiments described above is explicitly disclosed herein, as if each and every combination was individually and explicitly recited.

[0428] Various further aspects and embodiments of the present invention will be apparent to those skilled in the art in view of the present disclosure.

[0429] “and / or” where used herein is to be taken as specific disclosure of each of the two specified features or components with or without the other. For example “A and / or B” is to be taken as specific disclosure of each of (i) A, (ii) B and (iii) A and B, just as if each is set out individually herein.

[0430] Unless context dictates otherwise, the descriptions and definitions of the features set out above are not limited to any particular aspect or embodiment of the invention and apply equally to all aspects and embodiments which are described.

[0431] Certain aspects and embodiments of the invention will now be illustrated by way of example and with reference to the figures described above.

[0432] Examples

[0433] The following examples are provided to further illustrate the present invention and are not intended to limit the scope of the invention.

[0434] Experimental Equipment

[0435] The hydrogenation vessel is a Parr Series 4560 mini-reactor of 300 mL volume, made from stainless steel or Hastelloy. The vessel is equipped with 4-blade impeller stirrer.

[0436] WO-502116 008910770The dosage pump is a Wadose-Lite-HP-10-PE-l-S-C (company Wagner Mess- und Regeltechnik GmbH) with pump heads designed for flows between 0.005 and 10 mL / min. Distillations were performed in standard laboratory glassware.

[0437] Experimental Materials and Analytical Methods

[0438] Furfuryl alcohol was purchased from International Furan Chemicals B.V. and freshly distilled (3 mbar, 42 °C) before use.

[0439] The Raney-Nickel is BASF Actimet™ M.

[0440] The zeolite is ZSM-5 with SiO2:AI2O3 mole ratio of 80:1 , purchased from Zeolyst International (catalog designation CBV8014) or ThermoFisher (catalog number 045882.22).

[0441] Xylene was supplied by Sigma Aldrich as an isomeric mixture.

[0442] The zeolites were activated by calcination under air according to the following temperature ramp:

[0443] 1. Ambient to 90 °C over 20 min

[0444] 2. Hold at 90 °C for 120 min

[0445] 3. Ramp 90 °C to 110 °C over 20 min

[0446] 4. Hold at 110 °C for 120 min

[0447] 5. Ramp 110 °C to 500 °C over 80 min

[0448] 6. Hold at 500 °C for 4 hours

[0449] 7. Reduce temperature to room temperature

[0450] For Example 6, cyclopentanone was purchased from Sigma-Aldrich (article number W391018-1 KG-K).

[0451] HPLC Conditions

[0452] HPLC was used to analyse the test reactions.

[0453] HPLC analyses are done with the following method. Aliquots of approx. 250 mg product phase are dissolved in 10 mL of water.

[0454] The HPLC Conditions used were as follows:

[0455] HPLC: Thermo Vanquish

[0456] Column: XTerra RP18; 3.5 pm, 3.9 x 100 mm

[0457] Column temperature: 30 °C

[0458] Detection: UV @ 210 nm

[0459] Flow rate: 0.7 mL / min

[0460] Injection volumes: 1 pL

[0461] Mobile phase:

[0462] WO-502116 008910770Mobile phase A: 10 mL buffer solution (1M NaH2PO4 / H3PO4 pH 3.0) in 1000 mL water Mobile phase B: acetonitrile / water 90:10

[0463] Quantification: area percent

[0464] Retention times:

[0465] Furfuryl alcohol (1) 2.82 min

[0466] 4-Hydroxycyclopent-2-en-1-one (2) 1.58 min

[0467] Cyclopentenone (3) 2.30 min

[0468] Furfural (8) 3.41 min

[0469] GC Conditions

[0470] GC was used to analyse the test reactions. The GC Conditions used were as follows:

[0471] GC: Thermo Scientific Trace 1310

[0472] Autosampler: Thermo Scientific AS 1310

[0473] Column: Restek RTX-5; 30 m x 320 pm, 1.0 pm film

[0474] Injector temperature: 275 °C

[0475] Carrier gas / split / flow: Helium, 50:1, 1.3 mL / min (constant flow)

[0476] Oven temperature: 50 °C for 1.44 min, heat with 15 °C / min to 190 °C, hold for 8 min, heat with 40 °C / min to 260 °C and hold for 5 min.

[0477] Injection volumes: 1 pL

[0478] Detection: FID

[0479] Detector temperature: 275 °C

[0480] Quantification: area percent

[0481] The retention times for the reaction components are as follows:

[0482] Furfuryl alcohol (1) 7.0 min

[0483] 4-Hydroxycyclopent-2-en-1-one (2) 9.1 min

[0484] Succinonitrile (internal standard) 8.4 min

[0485] Cyclopentenone (3) 6.8 min

[0486] Cyclopentanone (4) 6.3 min

[0487] Cyclopentanol (5) 6.1 min

[0488] Tetrahydrofurfuryl alcohol 7.5 min

[0489] 2-Methyl-THF 4.6 min

[0490] NMR Conditions

[0491] Approximately 500 mg of product phase is dried in a stream of nitrogen for 4-5 h, then approximately 50 mg of succinonitrile is added. The mixture is dissolved in D2O and analysed by1H-NMR.

[0492] For assay calculation the spectrum is phase corrected, set to reference, baseline corrected and integrated. Integrals of cleaner peaks are preferred for the calculation.

[0493] WO-502116 008910770Example 1 - Furfuryl Alcohol to Cyclopentanone

[0494]

[0495] A series of test syntheses were carried out to demonstrate how the use of different organic-aqueous solvent systems and the gradual addition of furfuryl alcohol (1) to the reaction mixture can result in excellent yields of cyclopentanone (4).

[0496] Example 1A - Water / T oluene Solvent System

[0497] 1.2 g Raney-Nickel (wet, approx. 60 %), 108 g deionized water and 30 g toluene are placed in a pressure vessel. The vessel is pressurized with nitrogen to 2-3 bar, then pressure is released. This is performed three times (inertion). The vessel is pressurized with hydrogen to 2-3 bar, then pressure is released. This is performed three times. The vessel is heated to 167 °C, resulting in a pressure buildup of 10 bar. Pressure is increased to 11 bar by introduction of hydrogen and kept constant at 11 bar throughout the reaction by open connection to a hydrogen line set to that pressure.

[0498] 75 g furfuryl alcohol (freshly distilled) is dosed into the pressure vessel at a constant rate over approx. 25 h, then the dosage line is rinsed with 7.5 g deionized water. The reaction is continued for 6 h at 167 °C / 11-12 bar. The hydrogen line is disconnected. The vessel is cooled to 20-30 °C and residual pressure (4 bar) is released. The vessel is inerted with nitrogen, the two phases of the content are separated, weighed and analysed. The expected output is approx. 70 g of organic phase (orange) and approx. 150 g of aqueous phase (yellow, containing the sedimented Raney-nickel, pH 4.5-5.0).

[0499] In the organic phase, the cyclopentanone contents are 40-45 wt.% and the cyclopentanol contents 0-1 wt.%.

[0500] In the aqueous phase, the cyclopentanone contents 9-10 wt.% and the cyclopentanol contents are 0-1 wt.%.

[0501] The yields are about 70 % for cyclopentanone and 0-1 % for cyclopentanol. The toluene / water solvent system and the gradual addition of the furfuryl alcohol results in excellent selectivity and yield for the cyclopentanone product.

[0502] Following the reaction, no solid deposits besides small quantities of nickel are present in the vessel. The vessel is cleaned mechanically if deemed necessary and boiled out with water / ethanol or water / acetone two or three times. The pump and the transfer lines are rinsed with water, acetone, dichloromethane, acetone, water. The absence of deposits in the vessel

[0503] WO-502116 008910770allows for easy cleaning with minimal solvent needed for cleaning, before the vessel can be used again.

[0504] For isolation of cyclopentanone the biphasic mixture is distilled at atmospheric pressure using column distillation. All distillates are obtained as their respective azeotropes. Water removal from the biphasic product distillate was demonstrated by Dean-Stark-type distillation with cyclopentane. This was achieved with little to no product loss. To isolate the pure cyclopentanone (with a low level of cyclopentanol) the cyclopentane can be distilled off and the residue submitted to fine distillation. Removal of cyclopentane is performed via column to reduce product losses during the solvent distillation.

[0505] The distillation provides cyclopentanone at 99 % purity. The distillation is described in more detail in the ‘isolation example’ below.

[0506] Example 1B - Water / 2-Methyl-THF Solvent System

[0507] The synthesis was also tested with a Water and 2-methyl-THF solvent system.

[0508] 0.9 g Raney-Nickel (wet, approx. 60 %), 108 g deionized water and 30 g 2-Methyl-THF are placed in a pressure vessel. The vessel is pressurized with nitrogen to 2-3 bar, then pressure is released. This is performed three times (inertion). The vessel is pressurized with hydrogen to 2-3 bar, then pressure is released. This is performed three times. The vessel is heated to 167 °C, resulting in a pressure buildup of 13 bar. Pressure is increased to 14 bar by introduction of hydrogen and kept constant at 14 bar throughout the reaction by open connection to a hydrogen line set to that pressure.

[0509] 75 g furfuryl alcohol (freshly distilled) is dosed into the pressure vessel at a constant rate over approximately 32 h, then the dosage line is rinsed with 7.5 g deionized water. The reaction is continued for 13 h at 167 °C / 14 bar. The hydrogen line is closed / disconnected. The vessel is cooled to 20-30 °C and residual pressure (4-5 bar) is released. The vessel is inerted with nitrogen, the two phases of the content are separated, weighed and analysed. The expected output is 55-60 g of organic phase (yellow to orange) and 150-160 g of aqueous phase (yellow, containing the sedimented Raney-nickel, pH 4.0-4.5).

[0510] In the organic phase, the cyclopentanone contents are 35-45 wt.% and the cyclopentanol contents 1-4 wt.%. In the aqueous phase, the cyclopentanone contents are 11-13 wt.% and the cyclopentanol contents are 0-1 wt.%.

[0511] The yields are approximately 60-70 % for cyclopentanone and 1-10 % for cyclopentanol.

[0512] No solid deposits besides small quantities of nickel are present. The vessel is cleaned mechanically if deemed necessary and boiled out with water / ethanol or water / acetone two or three times. The pump and the transfer lines are rinsed with water, acetone, dichloromethane,

[0513] WO-502116 008910770acetone, water. The absence of deposits in the vessel allows for easy cleaning with minimal solvent.

[0514] For isolation of cyclopentanone / cyclopentanol the biphasic mixture is distilled at atmospheric pressure. A Vigreux column is used for distillation. All distillates are obtained as their respective azeotropes. Water removal from the biphasic product distillate was demonstrated by Dean-Stark-type distillation with cyclopentane. This is done with little to no product loss. To isolate the pure cyclopentanone (with a low level of cyclopentanol) the cyclopentane can be distilled off using column distillation, and the residue submitted to fine distillation. Removal of cyclopentane is performed via column to reduce product losses during the solvent distillation.

[0515] This example demonstrates that a 2-methyl-THF / water solvent system and the gradual addition of the furfuryl alcohol also results in excellent selectivity and yield for the cyclopentanone product.

[0516] The product mixture obtained in Example 1B was analysed by gas chromatography (GC).

[0517] A GC trace of the product mixture (upper phase, containing succinonitrile as internal standard, sample in acetonitrile) is shown in Figure 1.

[0518] A GC trace of product mixture (lower phase, containing succinonitrile as internal standard, sample in acetonitrile) is shown in Figure 2.

[0519] Example 1C- Water / Xylene Solvent System

[0520] The synthesis was also tested with a water and xylene solvent system. Xylene is not miscible with water, and therefore forms a biphasic solvent system. Xylene was supplied by Sigma

[0521] 0.75 g of BASF Raney-Nickel was provided in 116 mL of water and 30mL of xylene as the solvent system. 0.15 mol% of acetic acid was included as an additive. The solvent system was provided in a pressure vessel. The solvent system was heated to 157 °C at a pressure of 6 bar. Hydrogen was introduced to take the total pressure to 8 bar.

[0522] 37.5 g of furfuryl alcohol was dosed into the solvent system over 18 hours. The furfuryl alcohol was dosed as a solution of 40 wt.% furfuryl alcohol in water. The reaction was continued for a further 11 h at the same temperature and pressure.

[0523] The yields were determined by GC. The overall yield was 67 %, including 60 % cyclopentanone and 7 % cyclopentanol. This demonstrates the general feasibility of the chosen conditions.

[0524] WO-502116 008910770Example 1D - Water / methylcyclohexane Solvent System

[0525] The synthesis was tested with a water and methylcyclohexane solvent system.

[0526] Methylcyclohexane is not miscible with water, giving a biphasic solvent system.

[0527] 0.75 g of BASF Raney-Nickel was provided in 116 mL of water and 29 mL of methylcyclohexane as the solvent system. 0.-2 mol% of acetic acid was included as an additive. The solvent system was provided in a pressure vessel. The solvent system was heated to 153 °C and a pressure of 7 bar, and an addition 1 bar of hydrogen added.

[0528] 37.5 g of furfuryl alcohol was dosed into the solvent system over 18 hours. The furfuryl alcohol was dosed as a solution of 40 wt.% furfuryl alcohol in water. The reaction was continued for a further 8 h at the same temperature and pressure.

[0529] The combined yield was 43 %, including 41.2 % cyclopentanone. Although the overall yield is slightly lower than other examples, the degree of selectivity for cyclopentanone is excellent. Example 1E - Water / methyl-THF / methylcyclohexane Solvent System

[0530] The synthesis was tested with a water, 2-methyl-THF and methylcyclohexane solvent system. The organic solvents methylcyclohexane and methyl-THF are not miscible with water, giving a biphasic solvent system.

[0531] 1.5 g of BASF Raney-Nickel was provided in 116 mL of water, 18 mL of methylcyclohexane and 10 mL of 2-methyl-THF as the solvent system. The solvent system was provided in a pressure vessel. The solvent system was heated to 167 °C under hydrogen at a pressure of 13-14 bar.

[0532] 75 g of furfuryl alcohol was dosed into the solvent system over 28 hours. The furfuryl alcohol was dosed not in solution. The reaction was continued for a further 4 h at the same temperature and pressure.

[0533] The combined yield was 72 %, including 61.6 % cyclopentanone. The yield and selectivity for cyclopentanone is similar to the water / toluene solvent systems (e.g., Example 1A).

[0534] Example 2 - Solvent Systems

[0535] A series of experiments were carried out to compare an aqueous solvent system to an aqueous-organic solvent system. A pure organic solvent system was not investigated, as water is required for the reaction.

[0536] Example 2A - Water Solvent System

[0537] 5 g of furfuryl alcohol and 0.07 g of BASF Raney-Nickel were provided in 100 mL of water. The reaction mixture was heated to 160 °C at a pressure of 11-12 bar under a stream of

[0538] WO-502116 008910770hydrogen. The reaction was carried out for 5.5 h. Hydrogen absorption was still ongoing after 5.5 hours.

[0539] The reaction mixture was cooled to room temperature and worked up, by extraction of the aqueous phase three times with dichloromethane. The obtained phases were analysed. 4-Hydroxycyclopent-2-en-1-one and cyclopentenone could be observed and quantified by HPLC and GC.

[0540] The analyses showed that no significant amounts of furfuryl alcohol were remaining and that cyclopentenone was present in 25 % yield. Approximately 53 % of the furfuryl alcohol was lost to polymerization or side reactions. A significant amount of 4-hydroxycyclopent-2-en-1-one intermediate was present in the final product (~11 %).

[0541] Example 2B - Water Solvent System (MB2857)

[0542] Comparative Example 2B followed the same method as Comparative Example 2A, but with an 0.15 g of Raney-Nickel catalyst and a reaction time of 29 hours. Hydrogen absorption was still ongoing after 29 h.

[0543] Conversion was found to be complete in that no furfuryl alcohol or 4-hydroxycyclopent-2-en-1-one intermediates were detected. The yield of cyclopentanone was only 15 %. The yield of cyclopentanol was found to be 25 %, suggesting poor selectivity for cyclopentanone.

[0544] Example 2C- 1:1 Water / Toluene Solvent System

[0545] Example 2C followed the same method as Comparative Example 2A, but with a solvent system including 61.5 mL of water and 70.9 mL of toluene. The conditions were also adjusted to include 0.10 g of Raney-Nickel catalyst and a reaction time of 8 hours.

[0546] Conversion was found to be complete, despite the shorter reaction time than Comparative Example 2B. The yield of cyclopentanone was 51.3 %, which is significantly higher than the water based solvent system.

[0547] Example 2D - 23.6:1 Water / T oluene Solvent System

[0548] Example 2D followed the same method as Example 2C, but with 118 mL of water and 5.8 mL of toluene as the solvent system. This is a ratio of 23.6:1 of water to toluene (by volume) as the solvent system. The reaction was also carried out for 7.5 hours.

[0549] Conversion was complete as no furfuryl alcohol or intermediates were detected. The yield of cyclopentanone was 52.9 %. This demonstrates that even a relatively small amount of organic solvent can improve the yield of cyclopentanone.

[0550] WO-502116 008910770Comparative Example 2E - Water / NMP Solvent System

[0551] A further reaction was carried out based on Example 2A, but with a water / NMP solvent system. NMP is miscible with water, and so the solvent system is provided as a single phase.

[0552] 5 g of furfuryl alcohol and 0.17 g of BASF Raney-Nickel were provided in 100 mL of water and 12.1 mL of NMP as the solvent system. The reaction mixture was heated to 160 °C at a pressure of 9-11 bar under a stream of hydrogen. The reaction was carried out for 5.75 h.

[0553] After extraction (DCM) and quantification of the species of interest in both the organic and the aqueous phase, an overall yield of 55 % was determined. The final reaction mixture included substantial amounts of 4-hydroxycyclopent-2-en-1-one intermediate (20 %) and a yield of cyclopentanone of only 27 %.

[0554] The addition of NMP was found to have no significant positive effect on the isolated yield. It is thought that the miscibility of NMP with water meant that the benefits seen with the biphasic toluene / water solvent system were not observed.

[0555] The results from Examples 2A-2E are summarised in the following table:

[0556]

[0557] Example 3 - Gradual Addition

[0558] A series of experiments were carried out to investigate the effect of the concentration of furfuryl alcohol and the gradual addition of furfuryl alcohol on the reaction.

[0559] Example 3A - 1.5h addition

[0560] 0.10 g of BASF Raney-Nickel was provided in 77 mL of water and 20 mL of toluene. The reaction mixture was heated to 160 °C at a pressure of 9-11 bar under a stream of hydrogen (8 bar solvent vapour pressure).

[0561] 5 g of furfuryl alcohol was added to the solvent system over 1.5 hours. The furfuryl alcohol was added as a 25 wt.% solution in water. After the 1.5 hours, the pressure was increased to 14 bar and the reaction continued for 7 hours.

[0562] WO-502116 008910770The reaction was again very clean from a handling and appearance perspective. Overall yield was increased to 63 %, of which 60.6 % was cyclopentanone. In particular, the level of tetrahydrofurfuryl side product was very low at 0.3 %.

[0563] The gradual addition of the furfuryl alcohol appears to result in a improved yield of cyclopentanone, when compared to single addition procedures using similar solvent systems. Example 3B - 6h addition

[0564] Example 3B followed the same method as Example 3A, except that the 5 g of furfuryl alcohol was added to the solvent system over 6 hours. After the 6 hours, the pressure was increased to 12-13 bar and the reaction continued overnight.

[0565] An intermediate sample of the reaction mixture was taken at the end of the 6 hour addition period. The sample showed a 42 % intermediate yield of cyclopentanone at 85 % conversion of furfuryl alcohol. This suggests higher intermediate yield of cyclopentanone compared to processes where shorter dosage times were tested (e.g., Example 3A).

[0566] Once the reaction had completed, the total yield was 66 % and a yield of cyclopentanone was 60 %. This represents an increase in the total yield compared to Example 3A.

[0567] Example 3C- 18h addition at 10 % concentration

[0568] Example 3C follows a similar method to Example 3A and 3B, but at 50 % higher scale and a slower addition rate of furfuryl alcohol. The concentration of the furfuryl alcohol solution added to the solvent system was reduced to 10 wt.%, to allow for the slower rate of addition.

[0569] 0.15 g of BASF Raney-Nickel was provided in 115.5 mL of water and 30 mL of toluene. The reaction mixture was heated to 160 °C at a pressure of 9-10 bar under a stream of hydrogen (8 bar solvent vapour pressure).

[0570] 7.5 g of furfuryl alcohol was added to the solvent system over 18 hours. The furfuryl alcohol was added as a 10 wt.% solution in water. After the 18 hours, the pressure was increased to 12-14 bar and the reaction continued for 4.5 hours.

[0571] The overall yield was increased to 71 %, of which 67.6 % was cyclopentanone. The combined yield of cyclopentanone and cyclopentanol was 69 %. The even slower addition of the furfuryl alcohol appears to improve selectivity for cyclopentanone and improve the overall yield, even at a higher scale.

[0572] Example 3D - 19h addition at 20 % concentration

[0573] Example 3D follows a similar method to Example 3C, but at a higher concentration of furfuryl alcohol. The solvent system was unchanged, but 15 g of furfuryl alcohol was added as a 20 wt.% solution in water over 19 hours.

[0574] WO-502116 008910770The overall yield was increased to 72 %, of which 71.7 % was cyclopentanone. In contrast to batch processes, where an increase in starting material relative to the amount of solvent leads to significantly worse performance, in the case of gradual addition of the furfuryl alcohol the increased concentration gives a yield and selectivity for cyclopentanone is increased.

[0575] This represents an increase in product output from 28 g / L for Example 3C to 57 g / L for Example 3D.

[0576] Example 3E- 18h addition at 30 % concentration

[0577] Example 3D follows a similar method to Example 3C, but at an even higher concentration of furfuryl alcohol. The solvent system was unchanged, but 22.5 g of furfuryl alcohol was added as a 30 wt.% solution in water over 18 hours. A higher loading of catalyst was also provided (0.45 g of BASF Raney Nickel).

[0578] The overall yield was 71 %, of which 66.5 % was cyclopentanone. Although the yield was slightly reduced compared to Example 3D, the product output per volume was higher compared to lower concentration tests at over 68 g / L.

[0579] The results from Examples 3A-3E are summarised in the following table:

[0580]

[0581] These results show how the gradual addition of the furfuryl alcohol, when combined with a biphasic organic-water solvent system, results in an improved cyclopentanone yield.

[0582] Comparative examples where the furfuryl alcohol is added in a single dose at the start of the reaction (e.g., see Example 2C or 2D) show lower yields for cyclopentanone.

[0583] Example 4 - Isolation of Cyclopentanone

[0584] Aqueous and organic product phases of several previous examples using a water and toluene solvent system were combined.

[0585] WO-502116 008910770400 g of aqueous phase and 154 g of organic phase from Example 1B was adjusted to pH 7.4 by addition of a small amount of cone. NaOH solution and subjected to distillation at atmospheric pressure using a Sulzer-type column and a proper still head. At a reflux ratio of 5:1 the mixture was distilled over the course of three days.

[0586] The initial distillate was almost pure water / toluene azeotrope, collected at 84 °C head temperature, followed by cyclopentanone / water at 93 °C. Towards the end of the distillation the amounts of organic phases and their GC purities decrease significantly. In fraction 10 the organic phase was just sufficient for analysis and showed mostly impurities, the distillation was thus stopped. The remaining sump consisted of an upper clear, aqueous phase and a lower viscous, dark organic phase.

[0587] Initially the biphasic distillates were only analysed by GC.

[0588]

[0589] The organic and aqueous phases of fractions 3, 4-7 (combined) and 8 were separated and product assays were determined. In total, 49.6 g of cyclopentanone were obtained in approx.

[0590] 99 % purity by GC along with approx. 10 g of cyclopentanone in impure fractions (all of these as mixtures with water).

[0591] Based on assay determination, the crude phases used for the distillation contained 71.3 g of cyclopentanone.

[0592] WO-502116 008910770

[0593]

[0594] This demonstrates that high purity cyclopentanone can be obtained from the example processes.

[0595] Example 5 - Furfural to Cyclopentanone

[0596]

[0597] Furfural (8) is a common alternative to furfuryl alcohol (1) for the synthesis of cyclopentanone, furfuryl alcohol (1) can be obtained from furfural (8) by reduction of the aldehyde to an alcohol. The reduction may be carried out separately. The present example demonstrates a 0 reduction of furfural to furfuryl alcohol in a combined reaction with the rearrangement and reduction of furfuryl alcohol to cyclopentanone.

[0598] A water (20 vol) and toluene (4.6 vol) solvent system was provided with 0.15 g of Raney Nickel catalyst. 4.9 g of furfural was added under hydrogen at a pressure of 10-12 bar and a 5 temperature of 160 °C. The reaction time was 23 h. The overall yield was 30 %, and the yield of cyclopentanone was 29 %.

[0599] The selectivity for cyclopentanone was good. This demonstrates the viability of the process using a water and organic solvent system starting from furfural.

[0600] 0 Example 6 - Cyclopentanone to Cyclopentane

[0601] The onwards reaction of cyclopentanone to cyclopentane was carried out. The cyclopentanone was obtained from a commercial source. However, the same reaction may be carried out using cyclopentanone obtained in Example 1.

[0602] WO-502116 008910770

[0603]

[0604] 50 g Cyclopentanone, 0.6 g H-ZSM-5 zeolite and 1.2 g Raney-Nickel (wet, approx. 60 %) are placed in a pressure vessel. The vessel is pressurized with nitrogen to 2-3 bar, then pressure is released. This is performed three times (inertion). The mixture is heated to 170 °C with good agitation (approx. 500 RPM), resulting in a pressure buildup of approx. 3 bar. Hydrogen is introduced until a pressure of 30 bar is achieved, leading to a brief temperature increase to 177 °C. The pressure is kept constant at 30 bar throughout the reaction by open connection to a hydrogen line set to that pressure.

[0605] The reaction is stirred under these conditions for 24 h. The hydrogen line is closed / disconnected. The vessel is cooled to 20-30 °C and residual pressure (approx. 13 bar) is released.

[0606] The content is bottled and the upper (product) phase is analyzed by GC. The purity of the crude material is approx. 97 % (GCa / a).

[0607] The vessel is cleaned mechanically if deemed necessary and boiled out with water / ethanol or water / acetone one or two times.

[0608] Pure cyclopentane was obtained from the crude material by distillation at atmospheric pressure.

[0609] The aqueous phase and the catalyst deposits of the crude product can be removed before the distillation. If the aqueous phase is not removed, a lower head temperature (45-46 °C) is observed because the material boils as an azeotrope and the distillate contains a low amount of water.

[0610] It was observed that carrying out the reaction at pressures substantially lower than 30 bar to reduce side reactions, such as the formation of 1,1'-bi(cyclopentane) via an aldol reaction.

[0611] References

[0612] A number of publications are cited above in order to more fully describe and disclose the invention and the state of the art to which the invention pertains. Full citations for these references are provided below. The entirety of each of these references is incorporated herein.

[0613] WO-502116 008910770Dutta et al., ACS Omega, 2021, 6, 35145

[0614] Hronec et al., Catal. Commun., 2012, 24, 100

[0615] Kumaraguru et al., Org. Proc. Res. Dev. 2013, 17, 1526-1530 Ordomsky etal. Applied Catalysis A, 2013, 451, 6-13

[0616] Dohade et al., Catalysis Science and Technology, 2018. 8, 20, 5259-5269 CN 110 183317 B

[0617] WO-502116 008910770Statements of Invention

[0618] The following number paragraphs describe particular aspects and embodiment of the invention. Each and every compatible combination of the embodiments described in these number paragraphs is explicitly disclosed herein, as if each and every combination was individually and explicitly recited.

[0619] 1. A process for preparing cyclopentanone from furfuryl alcohol and / or furfural, the process comprising:

[0620] providing a biphasic solvent system, wherein the solvent system comprises water and an organic solvent;

[0621] adding furfuryl alcohol and / or furfural to the solvent system over a first time period; contacting the furfuryl alcohol and / or furfural with hydrogen and a hydrogenation catalyst over the first time period, to convert at least a portion of the furfuryl alcohol and / or furfural into cyclopentanone;

[0622] wherein the furfuryl alcohol and / or furfural are maintained in the solvent system at a concentration of 3 wt.% or less, based on the total mass of furfuryl alcohol and / or furfural and the solvent system, during the first time period.

[0623] 2. A process for preparing cyclopentanone from furfuryl alcohol and / or furfural, the process comprising:

[0624] providing a biphasic solvent system, wherein the solvent system comprises water and an organic solvent;

[0625] adding furfuryl alcohol and / or furfural to the solvent system over a first time period; contacting the furfuryl alcohol and / or furfural with hydrogen and a hydrogenation catalyst over the first time period, to convert at least a portion of the furfuryl alcohol and / or furfural into cyclopentanone;

[0626] wherein the maximum concentration of furfuryl alcohol and / or furfural in the solvent system during the first time period is Ai wt.%, based on the mass of furfuryl alcohol and / or furfural and the solvent system, during the first time period;

[0627] wherein the total amount of furfuryl alcohol and / or furfural added to the solvent system over the first time period is A2 wt.%, based on the total mass of furfuryl alcohol and / or furfural and the solvent system; and

[0628] A1 and A2 satisfy the Formula (I):

[0629] A2 / AI = B (I)

[0630] wherein B is greater than 1.

[0631] 3. The process of paragraph 2, wherein A1 is 3 wt.% or less, such as 2 wt.% or less, such as 1 wt.% or less.

[0632] WO-502116 0089107704. The process of paragraph 2, wherein Ai is from 0.01 to 3 wt.%, such as from 0.1 to 2 wt.%, such as from 0.2 to 1 wt.%.

[0633] 5. The process of any one of paragraphs 2 to 4, wherein A2 is 3 wt.% or more, such as 5 wt.% or more, such as 20 wt.% or more, such as 30 wt.% or more, such as 40 wt.% or more.

[0634] 6. The process of any one of paragraphs 2 to 4, wherein A2 is from 5 to 80 wt.%, such as 20 to 70 wt.%, such as from 30 to 60 wt.%, such as 40 to 55 wt.%.

[0635] 7. The process of any one of paragraphs 2 to 6, wherein B is 1.1 or more, such as 1.5 or more, such as 2 or more, such as 5 or more, such as 10 or more, such as 20 or more, such as 30 or more.

[0636] 8. The process of any one of the preceding paragraphs, wherein the organic solvent has:

[0637] (i) a solubility for cyclopentanone of 30 wt.% or more, such as 40 wt.% or more, wherein solubility is determined under ambient conditions; and / or

[0638] (ii) a solubility for poly(furfuryl alcohol) of 10 wt.% or more, such as 20 wt.% or more, wherein solubility is determined under ambient conditions.

[0639] 9. The process of any one of the preceding paragraphs, wherein the organic solvent is a substituted or unsubstituted C5-10 (hetero)arene, C5-10 (hetero)cycloalkane, C5-10 alkane, C2-10 heteroalkane or a combination thereof.

[0640] 10. The process of any one of the preceding paragraphs, wherein the organic solvent is a substituted Ce arene or C5 heterocycloalkane, or an or unsubstituted Ce cycloalkane, optionally wherein organic solvent is toluene, 2-methyl-THF or cyclohexane.

[0641] 11. The process of any one of the preceding paragraphs, wherein the mass ratio of water to organic solvent in the solvent system is 2 or more, such as 3 or more.

[0642] 12. The process of any one of the preceding paragraphs, wherein the organic solvent and water form an azeotrope.

[0643] 13. The process any one of the preceding paragraphs, wherein the furfuryl alcohol and / or furfural are present in the solvent system at a concentration of from 0.01 to 3 wt.%, such as 0.1 to 2 wt.%, such as 0.2 to 1 wt.%, during the first time period, based on the total mass of the furfuryl alcohol and / or furfural and the solvent system.

[0644] 14. The process of any one of the preceding paragraphs further comprising a step of:

[0645] measuring the concentration of furfuryl alcohol and / or furfural in the solvent sytem; comparing the measured concentration to a target concentration; and

[0646] WO-502116 008910770adjusting the rate of addition of the furfuryl alcohol and / or furfural in response to the comparison.

[0647] 15. The process of any one of the preceding paragraphs, wherein the furfuryl alcohol and / or furfural are added to the solvent system at an addition rate of from 0.5 to 10 wt.% / hour, such as from 1 to 5 wt.% / hour, such as from 1.5 to 3 wt.% / hour, wherein the addition rate is based on the mass of furfuryl alcohol and / or furfural added as a percentage of the initial mass of the solvent system.

[0648] 16. The process of paragraph 15, wherein the addition rate is constant during the first time period.

[0649] 17. The process of any one of the preceding paragraphs, wherein the total amount of furfuryl alcohol and / or furfural added to the solvent system over the first time period is from 10 to 80 wt.%, such as 30 to 70 wt.%, such as from 40 to 60 wt.%, based on the mass of furfuryl alcohol and / or furfural added as a percentage of the initial mass of the solvent system.

[0650] 18. The process of any one of the preceding paragraphs, further comprising contacting the furfuryl alcohol and / or furfural with hydrogen and a hydrogenation catalyst over a second time period, to convert at least a portion of the furfuryl alcohol and / or furfural into cyclopentanone;

[0651] wherein the second time period is after the first time period.

[0652] 19. The process of paragraph 18, wherein furfuryl alcohol and / or furfural are not added to the solvent system over the second time period.

[0653] 20. The process of any one of the preceding paragraphs, wherein the first time period is from 12 to 48 hours, such as from 24 to 36 hours and, where present, the second time period is from 1 to 24 hours, such as from 3 to 15 hours.

[0654] 21. The process of any one of the preceding paragraphs, wherein the conversion of furfuryl alcohol and / or furfural into cyclopentanone comprises:

[0655] optionally hydrogenating furfural to furfuryl alcohol;

[0656] rearranging furfuryl alcohol to 4-hydroxycyclopent-2-en-1-one; and

[0657] hydrogenating 4-hydroxycyclopent-2-en-1-one to cyclopentanone.

[0658] 22. The process of any one of the preceding paragraphs, wherein the process further comprises preparing cyclopentane from furfuryl alcohol and / or furfural, the process further comprising:

[0659] contacting cyclopentanone and / or cyclopentanol with hydrogen, a hydrogenation catalyst and an acid catalyst to convert at least a portion of the cyclopentanone and / or cyclopentanol into cyclopentane.

[0660] WO-502116 00891077023. The process of paragraph 22, wherein the second hydrogenation catalyst comprises a zeolite.

[0661] 24. The process of any one of the preceding paragraphs wherein contacting the furfuryl alcohol and / or furfural with hydrogen and a hydrogenation catalyst over the first time period is carried out at:

[0662] (i) a temperature of 100 °C or more, such as from 100 to 220 °C, such as from 120 to 200 °C, such as from 140 to 180 °C; and / or

[0663] (ii) a pressure of from 5 to 30 bar, such as from 7 to 20 bar, such as from 8 to 16 bar.

[0664] 25. The process of any one of the preceding paragraphs wherein the hydrogenation catalyst is a transition metal catalyst, such as a group 8 to 11 transition metal catalyst, such as a nickel, platinum or palladium catalyst, such as a Raney Nickel catalyst.

[0665] 26. The process of any one of the preceding paragraphs wherein the furfuryl alcohol and / or furfural is biobased, optionally wherein the furfuryl alcohol and / or furfural have a modern carbon content of 50 wt.% or more, such as 90 wt.% or more, such as 99 wt.% or more.

[0666] 27. The process of any one of the preceding paragraphs the biphasic solvent system further comprise a base.

[0667] 28. The process of paragraph 27 wherein the base is a water soluble base, such as a nitrogenous base, such as triethanolamine.

[0668] 29. The process of paragraph 27 wherein the base is a solid supported based, such as a solid supported amine, such as a phenylethyl-diethylamine.

[0669] 30. A product mixture comprising cyclopentanone, wherein the product mixture is obtained or obtainable by the process of paragraphs 1 to 29,

[0670] optionally wherein the product mixture comprises:

[0671] (i) 50 wt.% or more of cyclopentanone, such as 60 wt.% or more, such as 70 wt.% or more;

[0672] (ii) 10 wt.% or less of cyclopentanol, such as 7 wt.% or less, such as 4 wt.% or less; and / or

[0673] (iii) 40 wt.% or less of polyfurfuryl alcohol, such as 30 wt.% or less, such as 25 wt.% or less;

[0674] based on the total mass of reaction products in the product mixture.

[0675] 31. A product mixture comprising cyclopentanone, wherein the product mixture comprises:

[0676] (i) 50 wt.% or more of cyclopentanone, such as 60 wt.% or more, such as 70 wt.% or more;

[0677] (ii) 10 wt.% or less of cyclopentanol, such as 7 wt.% or less, such as 4 wt.% or less; and / or

[0678] WO-502116 008910770(iii) 40 wt.% or less of polyfurfuryl alcohol, such as 30 wt.% or less, such as 25 wt.% or less;

[0679] based on the total mass of reaction products in the product mixture.

[0680] 32. The product mixture of paragraph 30 or paragraph 31 , wherein the total amount of cyclopentanone is 3 wt.% or more, based on the total mass of the reaction products and the solvent system, such as 5 wt.% or more, such as 20 wt.% or more, such as 30 wt.% or more, such as 40 wt.% or more.

[0681] 33. The process of any one of paragraphs 1 to 29 or the product mixture of any one of paragraphs 30 to 32, wherein the cyclopentanone is biobased, optionally wherein the cyclopentanone has a modern carbon content of 50 wt.% or more, such as 90 wt.% or more, such as 99 wt.% or more.

[0682] 34. A reactor for preparing cyclopentanone from furfuryl alcohol and / or furfural, the reactor comprising:

[0683] a reaction vessel for a solvent system, wherein the solvent system comprises water and an organic solvent;

[0684] a source of furfuryl alcohol and / or furfural, for adding furfuryl alcohol and / or furfural to the reaction vessel over a first time period,

[0685] wherein the reaction vessel is for contacting the furfuryl alcohol and / or furfural with hydrogen and a hydrogenation catalyst over the first time period, to convert at least a portion of the furfuryl alcohol and / or furfural into cyclopentanone; wherein the furfuryl alcohol and / or furfural are present in the solvent system at a concentration of 3 wt.% or less, based on the total mass of furfuryl alcohol and / or furfural and the solvent system, during the first time period.

[0686] 35. A reactor for preparing cyclopentanone from furfuryl alcohol and / or furfural, the reactor comprising:

[0687] a reaction vessel for a solvent system, wherein the solvent system comprises water and an organic solvent;

[0688] a source of furfuryl alcohol and / or furfural, for adding furfuryl alcohol and / or furfural to the reaction vessel over a first time period,

[0689] wherein the reaction vessel is for contacting the furfuryl alcohol and / or furfural with hydrogen and a hydrogenation catalyst over the first time period, to convert at least a portion of the furfuryl alcohol and / or furfural into cyclopentanone; wherein the furfuryl alcohol and / or furfural is added to the solvent system at an addition rate of from 0.5 to 10 wt.% / hour, such as from 1 to 5 wt.% / hour, such as from 1.5 to 3 wt.% / hour, wherein the average addition rate is based on the mass of furfuryl alcohol and / or furfural added as a percentage of the initial mass of the solvent system.

[0690] 36. Use of a biphasic solvent system comprising water and an organic solvent, to improve the conversion of furfuryl alcohol and / or furfural to cyclopentanone, such as to increase the

[0691] WO-502116 008910770yield of cyclopentanone to 50 wt.% or more, such as 60 wt.% or more, such as 70 wt.% or more.

[0692] 37. A process for preparing cyclopentanone from furfuryl alcohol and / or furfural, the process comprising:

[0693] providing a biphasic solvent system, wherein the solvent system comprises water and an organic solvent;

[0694] adding furfuryl alcohol and / or furfural to the solvent system over a first time period; contacting the furfuryl alcohol and / or furfural with hydrogen and a hydrogenation catalyst over the first time period, to convert at least a portion of the furfuryl alcohol and / or furfural into cyclopentanone;

[0695] wherein the furfuryl alcohol and / or furfural is added to the solvent system at an addition rate of from 0.5 to 10 wt.% / hour, such as from 1 to 5 wt.% / hour, such as from 1.5 to 3 wt.% / hour, wherein the average addition rate is based on the mass of furfuryl alcohol and / or furfural added as a percentage of the initial mass of the solvent system, during the first time period.

[0696] WO-502116 008910770

Claims

Claims1. A process for preparing cyclopentanone from furfuryl alcohol and / or furfural, the process comprising:providing a biphasic solvent system, wherein the solvent system comprises water and an organic solvent;adding furfuryl alcohol and / or furfural to the solvent system over a first time period; contacting the furfuryl alcohol and / or furfural with hydrogen and a hydrogenation catalyst over the first time period, to convert at least a portion of the furfuryl alcohol and / or furfural into cyclopentanone;wherein the maximum concentration of furfuryl alcohol and / or furfural in the solvent system during the first time period is Ai wt.%, based on the mass of furfuryl alcohol and / or furfural and the solvent system, during the first time period;wherein the total amount of furfuryl alcohol and / or furfural added to the solvent system over the first time period is A2 wt.%, based on the total mass of furfuryl alcohol and / or furfural and the solvent system; andA1 and A2 satisfy the Formula (I):A2 / AI = B (I)wherein B is greater than 1.

2. The process of claim 1, wherein A1 is 3 wt.% or less, such as 2 wt.% or less, such as 1 wt.% or less.

3. The process of claim 1 or claim 2, wherein A2 is 3 wt.% or more, such as 5 wt.% or more, such as 20 wt.% or more, such as 30 wt.% or more, such as 40 wt.% or more.

4. The process of any one of the preceding claims, wherein B is 2 or more, such as 5 or more, such as 10 or more, such as 20 or more, such as 30 or more.

5. The process of any one of the preceding claims, wherein the organic solvent has:(i) a solubility for cyclopentanone of 30 wt.% or more, such as 40 wt.% or more, wherein solubility is determined under ambient conditions; and / or(ii) a solubility for poly(furfuryl alcohol) of 10 wt.% or more, such as 20 wt.% or more, wherein solubility is determined under ambient conditions.

6. The process of any one of the preceding claims, wherein the organic solvent is a substituted Ce arene or C5 heterocycloalkane, or an or unsubstituted Ce cycloalkane, optionally wherein organic solvent is toluene, 2-methyl-THF or cyclohexane.WO-502116 0089107707. The process of any one of the preceding claims, wherein the mass ratio of water to organic solvent in the solvent system is 2 or more, such as 3 or more.

8. The process of any one of the preceding claims, wherein the furfuryl alcohol and / or furfural are added to the solvent system at an addition rate of from 0.5 to 10 wt.% / hour, such as from 1 to 5 wt.% / hour, such as from 1.5 to 3 wt.% / hour, wherein the addition rate is based on the mass of furfuryl alcohol and / or furfural added as a percentage of the initial mass of the solvent system.

9. The process of any one of the preceding claims, further comprising contacting the furfuryl alcohol and / or furfural with hydrogen and a hydrogenation catalyst over a second time period, to convert at least a portion of the furfuryl alcohol and / or furfural into cyclopentanone;wherein the second time period is after the first time period.

10. The process of any one of the preceding claims, wherein the first time period is from 1 to 72 hours, such as from 12 to 48 hours, such as from 24 to 36 hours and, where present, the second time period is from 1 to 24 hours, such as from 3 to 15 hours.

11. The process of any one of the preceding claims, wherein the conversion of furfuryl alcohol and / or furfural into cyclopentanone comprises:optionally hydrogenating furfural to furfuryl alcohol;rearranging furfuryl alcohol to 4-hydroxycyclopent-2-en-1-one; andhydrogenating 4-hydroxycyclopent-2-en-1-one to cyclopentanone.

12. The process of any one of the preceding claims, wherein the process further comprises (i) preparing cyclopentanol from the cyclopentanone; and / or(ii) preparing cyclopentane from cyclopentanone and / or cyclopentanol, the process further comprising contacting cyclopentanone and / or cyclopentanol with hydrogen, a hydrogenation catalyst and an acid catalyst to convert at least a portion of the cyclopentanone and / or cyclopentanol into cyclopentane.

13. The process of any one of the preceding claims wherein contacting the furfuryl alcohol and / or furfural with hydrogen and a hydrogenation catalyst over the first time period is carried out at:(i) a temperature of 100 °C or more, such as from 100 to 220 °C, such as from 120 to 200 °C, such as from 140 to 180 °C; and / or(ii) a pressure of from 5 to 30 bar, such as from 7 to 20 bar, such as from 8 to 16 bar.

14. The process of any one of the preceding claims wherein the hydrogenation catalyst is a transition metal catalyst, such as a group 8 to 11 transition metal catalyst, such as a nickel, platinum or palladium catalyst, such as a Raney Nickel catalyst.WO-502116 00891077015. A product mixture comprising cyclopentanone, wherein the product mixture is obtained or obtainable by the process of claims 1 to 14,optionally wherein the product mixture comprises:(i) 50 wt.% or more of cyclopentanone, such as 60 wt.% or more, such as 70 wt.% or more;(ii) 20 wt.% or less of cyclopentanol, such as 7 wt.% or less, such as 4 wt.% or less; and / or(iii) 40 wt.% or less of polyfurfuryl alcohol, such as 30 wt.% or less, such as 25 wt.% or less;based on the total mass of reaction products in the product mixture.

16. The product mixture of claim 15, wherein the total amount of cyclopentanone is 3 wt.% or more, based on the total mass of the reaction products and the solvent system, such as 5 wt.% or more, such as 20 wt.% or more, such as 30 wt.% or more, such as 40 wt.% or more.

17. A reactor for preparing cyclopentanone from furfuryl alcohol and / or furfural, the reactor comprising:a reaction vessel for a solvent system, wherein the solvent system comprises water and an organic solvent;a source of furfuryl alcohol and / or furfural, for adding furfuryl alcohol and / or furfural to the reaction vessel over a first time period,wherein the reaction vessel is for contacting the furfuryl alcohol and / or furfural with hydrogen and a hydrogenation catalyst over the first time period, to convert at least a portion of the furfuryl alcohol and / or furfural into cyclopentanone;wherein the reactor is for adding furfuryl alcohol and / or furfural to the solvent system at an addition rate of from 0.5 to 10 wt.% / hour, such as from 1 to 5 wt.% / hour, such as from 1.5 to 3 wt.% / hour, wherein the average addition rate is based on the mass of furfuryl alcohol and / or furfural added as a percentage of the initial mass of the solvent system..

18. A process for preparing cyclopentanone from furfuryl alcohol and / or furfural, the process comprising:providing a biphasic solvent system, wherein the solvent system comprises water and an organic solvent;adding furfuryl alcohol and / or furfural to the solvent system over a first time period; contacting the furfuryl alcohol and / or furfural with hydrogen and a hydrogenation catalyst over the first time period, to convert at least a portion of the furfuryl alcohol and / or furfural into cyclopentanone;wherein the furfuryl alcohol and / or furfural is added to the solvent system at an addition rate of from 0.5 to 10 wt.% / hour, such as from 1 to 5 wt.% / hour, such as from 1.5 to 3 wt.% / hour, wherein the average addition rate is based on the mass of furfuryl alcohol and / or furfural added as a percentage of the initial mass of the solvent system, during the first time period.WO-502116 008910770

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