Method for extracting phragmalin derivative from melia taxifolia seeds and preparing limonin analogue with pharmaceutical activity

Abstract

The present invention relates to a method for obtaining a phrgamalin derivative of formula (Ia), e.g., from an extract of Azadirachta caudate seed, and thereby producing therapeutically active limonin analogs and limonin-based compounds, such as, e.g., a compound of formula (V), in a multi-step synthesis involving, e.g., an intermediate of formula (III). # imgabs0 #

Description

Technical Field

[0001] The present invention generally relates to improvements in the preparation of therapeutically active limonoid analogs (limonoids) and novel limonoid-type compounds. Background Art

[0002] EP 2807170 discloses plant-derived limonin analogs that can be used to treat sexual dysfunction and have a sexual enhancement effect. The article proposes the use of phragmalin esters extracted from the seed source of Chukrasia tabularis, and through a lengthy process, including alkaline hydrolysis, conversion to Weinreb amide and repositioning the phragmalin lactone ring, to obtain the desired use of limonin analogs. Thus, the production method in EP 2807170 has low yields and it is difficult to obtain raw materials from Chukrasia tabularis. It would be an extremely difficult and expensive way to produce limonin analogs in reasonable quantities to develop and launch therapeutic products based on limonin analogs. Therefore, a more efficient way is needed to produce desirable limonin analogs. Summary of the invention

[0003] This document relates to a method for obtaining at least one of the compounds of formula Ia and formula Ib:

[0004]

[0005] wherein R1 is a linear, branched or cyclic alkyl group having 1 to 6 carbon atoms, which is unsubstituted or substituted, for example, by OH or halogen, such as F, the method comprising:

[0006] (i) providing a composition comprising:

[0007] At least one of the compounds of formula IIa and formula IIb,

[0008]

[0009] in

[0010] R1 is as defined above,

[0011] R2 and R3 are independently selected from linear, branched or cyclic, substituted or unsubstituted alkyl groups having 1 to 6 carbon atoms or from nicotinoyl groups; and / or

[0012] Provided is an extract composition from Entandrophragma caudatum comprising at least a compound of formula IIa, wherein

[0013] a) R2 and R3 are independently selected from a linear or branched alkyl group having 1 to 6 carbon atoms or a nicotinyl group; and

[0014] b) R1 is methyl;

[0015] (ii) subjecting the extract composition and / or optionally the composition from step (i) to one or more distillations and introducing a solvent comprising an aliphatic alkanol;

[0016] (iii) performing an alkanolysis reaction by adding an aliphatic metal alkoxide in the presence of an aliphatic alcohol to initiate the reaction, and then adding an acid, preferably an organic acid such as acetic acid, to terminate the alkanolysis reaction, thereby obtaining at least one of the compounds of Formula Ia and Formula Ib.

[0017] This document also discloses a method for producing a compound of formula Ib from a compound of formula Ia, the method comprising:

[0018] (i) reacting the compound of formula Ia with a base strong enough to open the lactone ring but not to hydrolyze the group R1 to form a carboxyl group, preferably the base is barium hydroxide octahydrate in methanol, to obtain a compound of formula III;

[0019]

[0020] (ii) reacting a compound of formula III with a selective oxidizing agent, preferably Dess Martin periodinane, to obtain a compound of formula IV; and

[0021]

[0022] (iii) reacting a compound of formula IV with a coupling agent, preferably a carbodiimide coupling agent, such as 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride (EDC.HCl) in the presence of a sterically hindered organic base, preferably N,N-diisopropylethylamine (DIPEA), thereby obtaining a compound of formula Ib.

[0023] This document also relates to a process for producing a compound of formula V from a compound of formula Ib, said process being carried out by reacting the compound of formula Ib with an esterifying agent and a sterically hindered base to selectively introduce a group R2′ of formula V,

[0024]

[0025] wherein R2′ is a linear, branched or cyclic optionally substituted alkyl group having 1 to 6 carbon atoms.

[0026] The present document also relates to a compound of formula III. (The present document also relates to a compound according to claim 13, wherein R1 is methyl.

[0027] This document also relates to a compound according to claim 15 or 16, which is obtainable or obtainable by the process of claim 9, step (i).

[0028] This document also relates to a compound of formula IV.

[0029] This document also relates to compounds according to claim 18, wherein R1 is methyl.

[0030] This document also relates to a compound according to claim 18 or 19, which is obtainable or obtainable by the process of step (ii) of claim 9.

[0031] This document also relates to a monohydrate salt of a compound according to formula V, wherein R1 is preferably methyl.

[0032] This document also relates to a compound according to formula V, with the proviso that R1 is not hydrogen, methyl or ethyl.

[0033] This document also relates to an extract composition of Endoandrum caudatum prepared from the seeds of Endoandrum caudatum, the extract composition of Endoandrum caudatum comprising at least one of the compounds according to Formula IIa and Formula IIb, wherein the extract composition of Endoandrum caudatum is produced by:

[0034] (i) mixing ground seeds of Echinops caudatus with methanol, filtering, collecting and concentrating to obtain a concentrated methanol extract;

[0035] (ii) mixing the concentrated methanol extract with a less polar solvent and a more polar solvent to obtain a two-phase composition, and discarding the more polar solvent phase to eliminate polar impurities and concentrating the less polar solvent phase, preferably by distillation, thereby obtaining an extract composition of Endoandromeda caudatus.

[0036] "Less polar" and "more polar" solvents in the methods refer to the polarity of the solvents relative to each other.

[0037] This document also relates to a method for producing an extract composition of Endoandrum caudatum prepared from the seeds of Endoandrum caudatum, said extract composition of Endoandrum caudatum comprising at least one of the compounds according to formula IIa and / or the precursors of formula Ib, said method comprising the following steps:

[0038] i) mixing the ground seeds with methanol, filtering, collecting and concentrating to obtain a concentrated methanol extract;

[0039] ii) mixing the concentrated methanol extract with a less polar solvent and a more polar solvent to obtain a two-phase composition, and discarding the more polar solvent phase to eliminate polar impurities and concentrating the less polar solvent phase, preferably by distillation, thereby obtaining an extract composition of Endoandromeda caudatus.

[0040] "Less polar" and "more polar" solvents in the methods refer to the polarity of the solvents relative to each other.

[0041] This document also relates to a method for producing the compound of formula VI (9R, 15S, 16S, 17S, 18S)-4-(furan-3-carbonyl)-15-hydroxy-18-(2-methoxy-2-oxoethyl)-4,12,17,19-tetramethyl-7-oxo-8,11,13,20-tetraoxacyclo[10.7.1.114,17.01,10.05,10.09,15.014,19]heneicosane-16-yl 2-methylpropanoate monohydrate

[0042]

[0043] The method comprises the following steps:

[0044] (i) using the method according to any one of claims 1 to 8 to obtain at least one of the compound of formula Ia wherein R1 is methyl and the compound of formula Ib wherein R1 is methyl;

[0045] (ii) collecting the compound of formula Ia separately and converting it into a compound according to formula Ib using the method according to claim 9; and

[0046] (iii) converting the compound according to formula Ib collected from steps (i) and (ii) using a process according to claim 11 or 12 to obtain a compound of formula lib, wherein R2 is isopropyl. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] Figure 1 shows the formula Ia ( Figure 1a ) and Formula Ib( Figure 1b ) of the compound having carbon atoms.

[0048] Figure 2 An overview of the preparation of methanol extract from the seeds of Endanthera caudatum is shown.

[0049] Figure 3 An overview of the preparation of an extract composition of Endoandraceae in ethyl acetate is shown.

[0050] Figure 4 An overview of the methanolysis reaction performed according to Example 2 is shown.

[0051] Figure 5 A three-step synthesis for converting compounds of Formula Ia to compounds of Formula Ib is shown.

[0052] Figure 6 The IR spectrum of the compound of Formula V produced according to Example 2 is shown. DETAILED DESCRIPTION

[0053] Process for obtaining compounds of formula Ia and / or formula Ib

[0054] The present document relates to methods that enable improved production, e.g., scale-up and industrial commercialization of therapeutically active limonoid analogs as well as novel limonoid compounds to be obtained.

[0055] In one aspect, the present invention relates to a method for obtaining compounds of formula Ia and formula Ib

[0056]

[0057] Wherein R1 is a linear, branched or cyclic alkyl group having 1 to 6 carbon atoms, which is unsubstituted or substituted by one or more groups selected from OH and halogen. For example, R1 may be a methyl or trifluoromethyl group.

[0058] The method comprises providing a composition comprising at least one of a compound of Formula IIa and Formula IIb:

[0059]

[0060] wherein R1 is as defined above, and R2 and R3 are independently selected from a linear, branched or cyclic, substituted or unsubstituted alkyl group having 1 to 6 carbons or from a nicotinyl group.

[0061] In the composition, the compound of formula IIa and / or IIb may be of natural or synthetic origin, and the composition may contain at least one alkanol solvent suitable for the subsequent alkanollysis step. Alternatively, in the method or as a supplement to the above composition, an extract composition of Endoandrum caudatum is provided (see below). The extract composition of Endoandrum caudatum comprises at least one compound of formula IIa, wherein R2 and R3 are independently selected from linear or branched alkyl groups having 1 to 6 carbon atoms or from nicotinoyl groups; and R1 is methyl.

[0062] As the next step of the process, the composition comprising at least one of the compounds of formula IIa and IIb and / or the extract composition of Endoandromeda caudatus is optionally subjected to one or more distillations to remove water and any other solvent that may interfere with the subsequent alkanolization. In this step, an alkanol solvent is introduced that is compatible with the subsequent alkanolization. The alkanol is preferably selected from a linear or branched C1-C6 alcohol.

[0063] Alkanollysis is performed by adding an aliphatic metal alkoxide to start the reaction, and then adding an acid, preferably an organic acid such as acetic acid, to terminate the reaction, thereby obtaining at least one of the compounds of Formula Ia and Formula Ib.

[0064] In an embodiment, the method is performed using an extract composition of Endoandraceae caudatus.

[0065] The extract composition of Endoandraceae preferably comprises at least one of phragmalin-3,30-di-isobutyrate, phragmalin-3-isobutyrate-30-propionate, phragmalin-3-nicotinate-30-isobutyrate and / or at least one precursor of the compound of formula Ib.

[0066] The subsequent purification process for purifying the mixture of at least one of the compounds of Formula Ia and Formula Ib obtained from the alkanolysis generally comprises continuous extraction with polar and non-polar fluids to remove polar and non-polar impurities. The purification process comprises the steps of drying the mixture (e.g., drying with a water absorbent) to remove water and using a polar extraction liquid and a step of concentrating under reduced pressure. In an embodiment of the purification process, the polar impurities may first be removed with one or several polar fluids, followed by drying and concentration, and then the non-polar impurities may be removed with one or more non-polar / non-water miscible fluids.

[0067] In an embodiment of the method, the step of removing polar impurities from the compounds of Formula Ia and Formula Ib may include removing the solvent containing the alkanol from the alkanolysis; adding one or more polar extracting liquids, and optionally removing water by adding a water absorbing agent, such as sodium sulfate, MgSO 4 、CaSO 4 , CaCl 2 、K2CO 3 To obtain a crude mixture of the compounds. The polar extract can be ethyl acetate, water or a mixture thereof, or a sodium chloride aqueous solution. However, those skilled in the art may find similar useful alternatives.

[0068] In an embodiment of the method, the step of removing non-polar impurities is dissolving the non-polar impurities in a non-polar / water-non-miscible solvent, preferably hexane or a solvent with a polarity index similar to hexane, such as pentane, cyclohexane, heptane, and discarding the solvent phase with the non-polar impurities to obtain a crude mixture.

[0069] In an embodiment of the process, the process comprises concentrating the crude mixture obtainable according to or according to the above process by removing polar impurities as outlined above and contacting it at least once with a non-polar / water-immiscible solvent as previously outlined, thereby obtaining a compound of Formula Ia and / or Formula Ib in solid form.

[0070] In an embodiment of the method, the method comprises the steps of chromatographically separating the compound of formula Ia from the compound of formula Ib, and separately collecting and purifying the compounds of formula Ia and formula Ib, respectively. Preferably, the final purity of each of the compounds is at least 90%. Preferably, the chromatography is performed after the successive steps of removing polar and non-polar impurities.

[0071] In an embodiment of the method, the alkanolysis is a methanolysis reaction in a methanol solvent, comprising adding a methoxide, preferably sodium methoxide.

[0072] Process for producing compounds of formula Ib

[0073] In one aspect, the invention relates to a process for producing a compound of formula Ib from a compound of formula Ia, the process comprising as a first step reacting a compound of formula Ia with a base strong enough to open the lactone ring but not to hydrolyze the group R1 to form a carboxyl group, preferably the base is barium hydroxide octahydrate in methanol, to obtain a compound of formula III. For the lactone ring opening, the skilled person can find alternative suitable bases, containing hydroxyl groups or alternatively by acid, enzymatically or, for example, with sodium trimethylsilanol ((TMS)ONa).

[0074]

[0075] In the second step, the process comprises reacting the compound of formula III with a selective oxidizing agent to obtain the compound of formula IV.

[0076]

[0077] The oxidizing agent in the second step is selected from Dess-Martin periodinane, pyridinium chlorochromate, Swern oxidation (oxalyl chloride and DMSO), Corey-Kim oxidation, Jones oxidation (chromium trioxide), TEMPO and Burgess reagent. Preferably, the oxidizing agent is Dess-Martin periodinane.

[0078] In the third step, the method comprises reacting a compound of formula IV with a coupling agent in the presence of a sterically hindered organic base, thereby obtaining a compound of formula Ib having a substituted lactone ring.

[0079] The coupling agent in the third step is selected from carbodiimide coupling agents, such as 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride (EDC.HCl), N,N'-dicyclohexylcarbodiimide (DCC), N,N'-diisopropylcarbodiimide (DIC) and DCC / HOBt (hydroxybenzotriazole). Preferably, the coupling agent is 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride.

[0080] The sterically hindered organic base in the coupling reaction of the third step is selected from N-diisopropylethylamine (DIPEA), dimethylaminopyridine (DMAP), triethylamine (TEA) and 4-pyrrolidinylpyridine (PPY), preferably, the base is preferably N,N-diisopropylethylamine (DIPEA).

[0081] Process for producing compounds of formula V

[0082] In one aspect, the present invention relates to a process for producing a compound of formula V from a compound of formula Ib by reacting the compound of formula Ib with an esterifying agent and a sterically hindered base to selectively introduce a group R2' into formula V.

[0083]

[0084] In formula V, R2' is a linear, branched or cyclic optionally substituted alkyl group having 1 to 6 carbon atoms and R1 is as previously defined. The skilled person can envision many different esterifying agents, such as acid chlorides, acid anhydrides, etc. Useful sterically hindered bases are mentioned in the previous section. The preparation of compounds according to formula Ib is carried out according to the content outlined in the previous section.

[0085] In one embodiment of the method of producing the compound of Formula V, R2' is isopropyl and R1 is methyl, the esterifying agent is isobutyryl chloride, and wherein DMAP-HCl is used as a sterically hindered base.

[0086] In an embodiment, the method of producing the compound of formula V may further include purifying the compound of formula V with a polar solvent and continuously with polar solvents, and finally washing the compound with a bipolar solvent (preferably acetone and water), thereby obtaining a solid monohydrate of the compound of formula V.

[0087] Compound

[0088] In one aspect, the invention relates to a compound of formula III. In embodiments, the compound has a methyl group as substituent R1. In embodiments, formula III is obtained or can be obtained by the methods outlined previously.

[0089] In one aspect, the invention relates to a compound of formula IV. In an embodiment, the compound has a methyl group as substituent R1 and is obtained or obtainable by a process as previously outlined.

[0090] In one aspect, the invention relates to a monohydrate salt of a compound according to formula V, such as a compound having a methyl group as a substituent (preferably R1).

[0091] In one aspect, the invention relates to compounds according to formula V, with the proviso that R1 is not methyl, ethyl or hydrogen.

[0092] Extract composition of Endoandraceae caudatum and production method thereof

[0093] In another aspect of the present invention, it relates to an extract composition of Endoandrum caudatum prepared from the seeds of Endoandrum caudatum, the extract composition of Endoandrum caudatum comprising at least one of the compounds according to Formula IIa and Formula IIb and / or the precursor of the compound of Formula Ib.

[0094] The extract composition of Endoandrophila caudatum is a natural product extracted from the ground seeds of Endoandrophila caudatum. The seeds are loaded into a glass reactor and methanol is added for extraction. The slurry is mixed at 40°C for at least 15 hours and then filtered under inert N2 pressure. Additional methanol is added to wash the filter cake and pipes. The filtered solution containing the extracted material is introduced into a container and loaded back into the glass reactor in batches, concentrated by vacuum distillation, and a methanol extract is obtained. The methanol extract is concentrated to dryness, dissolved in ethyl acetate and washed with water. The ethyl acetate is concentrated and the extract composition of Endoandrophila caudatum is collected as a dark yellow solution in ethyl acetate. The extract composition of Endoandrophila caudatum contains phragmalin-3,30-di-isobutyrate, phragmalin-3-isobutyrate-30-propionate, phragmalin-3-nicotinate-30-isobutyrate and a precursor of the compound of formula Ib.

[0095] For example, the extract composition of Endoandromeda caudatus can be produced by:

[0096] i) mixing ground seeds of Echinops caudatus with methanol, filtering, collecting and concentrating to obtain a concentrated methanol extract;

[0097] ii) mixing the concentrated methanol extract with a less polar solvent and a more polar solvent to obtain a two-phase composition, and discarding the more polar solvent phase to eliminate polar impurities and concentrating the less polar solvent phase, preferably by distillation, thereby obtaining an extract composition of Endoandromeda caudatus.

[0098] In an embodiment of the extract composition, the less polar solvent forms an azeotrope with the more polar solvent in the step. Preferably, the less polar solvent is ethyl acetate and the more polar solvent is water, but other combinations of less polar / more polar solvents are possible to the skilled person. More preferably, the less polar solvent and the more polar solvent are ethyl acetate and water, respectively, in a volume ratio of 2:1.

[0099] In an embodiment of the extract composition, it comprises at least one of the compounds phragmalin-3,30-di-isobutyrate and phragmalin-3-isobutyrate-30-propionate, phragmalin-3-nicotinate-30-isobutyrate and a precursor of the compound of formula Ib.

[0100] In another aspect of the present invention, it relates to a method for producing an extract composition of Endoandrum caudatum prepared from the seeds of Endoandrum caudatum as described above, the extract composition of Endoandrum caudatum comprising at least one of the compounds according to Formula IIa and Formula IIb, the method comprising the following steps:

[0101] i) mixing ground seeds of Echinops caudatus with methanol, filtering, collecting and concentrating to obtain a concentrated methanol extract;

[0102] ii) mixing the concentrated methanol extract with a less polar solvent and a more polar solvent to obtain a two-phase composition, and discarding the more polar solvent phase to eliminate polar impurities and concentrating the less polar solvent phase, preferably by distillation, thereby obtaining an extract composition of Endoandromeda caudatus.

[0103] In an embodiment of the method, the less polar solvent in step ii) forms an azeotrope with water, preferably the less polar solvent comprises ethyl acetate and the more polar solvent comprises water. Preferably, the less polar solvent and the more polar solvent in step ii) are ethyl acetate and water, respectively, more preferably in a volume ratio of 2:1.

[0104] Process for producing the monohydrate of the compound of formula VI

[0105] In yet another aspect of the present invention, it relates to a method for producing the compound of formula VI (9R, 15S, 16S, 17S, 18S)-4-(furan-3-carbonyl)-15-hydroxy-18-(2-methoxy-2-oxoethyl)-4,12,17,19-tetramethyl-7-oxo-8,11,13,20-tetraoxacyclo[10.7.1.114,17.01,10.05,10.09,15.014,19]heneicosane-16-yl 2-methylpropanoate monohydrate.

[0106]

[0107] The method comprises the step of obtaining at least one of a compound of formula Ia (wherein R1 is methyl) and / or a compound of formula Ib (wherein R11 is methyl) using the method previously outlined. As a next optional step, the compound of formula Ia is collected separately and converted into a compound according to formula Ib using the method previously outlined. The collected compound according to formula Ib (wherein R2 is isopropyl) is then converted into formula VI using the method previously outlined. Finally, the monohydrate of formula VI is obtained using the purification and washing methods as previously outlined.

[0108] In an embodiment of the method, the starting material is an extract composition of Endoandrum caudatum, prepared as described above.

[0109] Experimental Section

[0110] Example 1: Preparation of extract composition from seeds of Echinops caudatus

[0111] Overview of the Program:

[0112] The extract composition of Endoandrophila caudatum is a natural product extracted from the ground seeds of Endoandrophila caudatum. The seeds are loaded into a glass reactor and methanol is added for extraction. The slurry is mixed at 40°C for at least 15 hours and then filtered under inert N2 pressure. Additional methanol is added to wash the filter cake and pipes. The filtered solution containing the extracted material is introduced into a container and loaded back into the glass reactor in batches, concentrated by vacuum distillation, and a methanol extract is obtained. The methanol extract is concentrated to dryness, dissolved in ethyl acetate and washed with water. The ethyl acetate is concentrated and the extract composition of Endoandrophila caudatum is collected as a dark yellow solution in ethyl acetate. The extract composition of Endoandrophila caudatum contains phragmalin-3,30-di-isobutyrate, phragmalin-3-isobutyrate-30-propionate, phragmalin-3-nicotinate-30-isobutyrate and a precursor of the compound of formula Ib.

[0113] Detailed description of the program:

[0114] Step 1: Preparation of methanol extract (for an overview of the procedure see Figure 2 )

[0115] Methanol (about 800L) is loaded into a nitrogen-filled glass reactor and stirring is started. About 100kg of ground seeds of the caudate neem are added. The glass reactor is then evacuated and refilled with nitrogen. The temperature of the reactor is set to 40°C and the contents are stirred for at least 15-20 hours. The mixture is then filtered on a polyamide filter cloth (25 μm) by applying a pressurized nitrogen atmosphere, and the filtrate is collected in a container. Methanol is then loaded into a feed container (about 100L), and methanol is directly loaded into the filter from the feed container bypassing the glass reactor (twice, 50L each time), and the filtrate is collected in a container. The mixture is then filtered again on a polyamide filter cloth by repeating the procedure. The filter cake is then dried under vacuum for at least one hour. The filtrate is then loaded into a glass reactor (about 800L in total) and the contents are stirred. The methanol solvent is then distilled off under vacuum at a temperature of 40-70°C jacket temperature (the internal temperature during distillation is about 21-29°C). The distillation was continued until approximately 200 L remained in the glass vessel. Care must be taken not to distill off too much methanol as the remaining contents would be too viscous to remove from the glass vessel. The jacket temperature was then adjusted to approximately 20-25°C and the concentrated methanol extract was collected.

[0116] Step 2: Preparation of an extract composition of E. caudatum in ethyl acetate (for an overview of the procedure see Figure 3 )

[0117] The concentrated methanol extract (about 400 L, ie, two batches of step 1) prepared as described above in step 1 was charged into a nitrogen-filled glass reactor, and the temperature of the reactor was adjusted to 75°C and the stirrer was started.

[0118] Methanol was distilled off under vacuum to obtain a dry mixture, after which the temperature was adjusted to 20°C.

[0119] Ethyl acetate (EtOAc) (about 400 L) was then charged into the reactor. Water (about 170 L) was then charged. The temperature of the reactor was set to 40°C and the contents of the reactor were stirred for about 30 min while maintaining the temperature at 40°C.

[0120] The stirrer was then stopped and the two phases were allowed to separate for 30 to 60 min until layer separation was achieved. The aqueous layer was then discarded.

[0121] The temperature of the reactor was then adjusted to 55-75°C and the mixture remaining after the removal of water was concentrated under vacuum. When the volume was reduced to about 50 L (i.e., when about 350 L of distillate was collected), the distillation was stopped. The extract composition of Endoandros caudatus in ethyl acetate was then collected. When stored before further use, the extract composition was stored at 5°C ± 3°C.

[0122] Example 2 - Synthesis of Compounds of Formula V

[0123] Overview of the program (see also Figure 4 ):

[0124] The starting material for the synthesis of the compound of Formula V contains a mixture of material extracted from the seeds of E. caudatum and residual solvent from the extraction procedure. The extract composition of E. caudatum was prepared according to Example 1.

[0125] The starting material contains about 10% of mainly two different molecules of compounds of formula IIa and possibly precursor molecules of one or more compounds of formula Ib as materials of interest for further synthesis.

[0126] The two most important molecules of formula IIa identified in the extract composition of E. caudatum are:

[0127] a. Phragmalin 3,30-diisobutyrate

[0128] b. Phragmalin 3-isobutyrate-30-propionate

[0129] The precursor molecule of Formula Ib has not yet been fully identified.

[0130] The two compounds of formula IIa and possible precursors of formula Ib in the seed extract are converted to compounds of formula Ia and Ib, respectively, by a methanolysis procedure followed by purification to obtain pure compounds of formula Ia and Ib. The compound of formula Ia is then converted to the compound of formula Ib in three synthetic steps. The compound of formula Ib is finally converted to the compound of formula V in one step.

[0131] Detailed description of the program:

[0132] Conversion of the compound of formula IIa and the precursor of formula Ib into the compound of formula Ia and Ib

[0133] Methanol solution:

[0134] An overview of the methanolysis reaction is as follows Figure 4 as shown in .

[0135] The ethyl acetate extract (138 Kg from the previous step) was dissolved in methanol (690 L, 5 vol) and distilled until no distillate was observed. Methanol (690 L, 5 vol) was added to the material and further distilled until no effluent was observed at 45°C to obtain 105 kg of solvent-free extract residue as brown syrup.

[0136] The extract residue (105 kg, 1.0 eq) was dissolved in methanol (1050 L, 10.0 V) and cooled to 15 ± 5 ° C. Sodium methoxide (15.75 kg, 0.15% w / w) was added in four equal portions with a time interval of 10 minutes between each addition and a temperature below 30 ° C. (an exotherm of 5-10 ° C was observed during the addition of sodium methoxide). The reaction mixture was stirred at 45 ± 5 ° C for 40 h.

[0137] Post-processing:

[0138] The pH of the reaction mass was adjusted to 6.0 to 7.0 using acetic acid (about 15.75 kg, about 0.15% w / w) at 15±5°C and purified water (315 L, 3.0 V) was added at less than 30°C. The reaction mass was concentrated under reduced pressure at a temperature below 45°C to remove methanol. The residue was diluted with ethyl acetate (1050 L, 10.0 V), purified water (420 L, 4.0 V) was added, followed by sodium chloride (21 kg, 0.2% w / w) and stirred for 15 min. The biphasic medium was separated and re-extracted with ethyl acetate (735 L, 7.0 V). The combined organic layer was washed with 10% sodium chloride solution (735 L, 7.0 V), separated, and dried over anhydrous sodium sulfate (about 21 kg, 0.2% w / w). The organic layer was concentrated under reduced pressure at a temperature below 45°C to obtain a crude mixture of compounds of Formula Ia and Ib.

[0139] The hexane slurry was then subjected to column purification:

[0140] Hexane (1050L, 10.0V) is added to the residue, heated to 40 ± 5 ° C and stirred for 2 hours. The mixture is cooled to 25 ± 5 ° C and stirred for 8 hours. The precipitated solid is collected by filtration and washed with hexane (210L, 2.0V) to obtain a crude mixture of about 13.36kg of formula Ia and Ib compounds in a light yellow solid (all non-polar impurities are washed out with hexane purification). The compound of formula Ia and Ib is separated from the crude mixture by column chromatography. After column chromatography, about 4.17kg of the compound of formula Ia and 2.94kg of the compound of formula Ib are obtained.

[0141] Purification of Compounds of Formula Ia:

[0142] The crude compound of formula Ia (4.17 kg) was stirred with isopropyl alcohol (IPA) (8.3 L, 2.0 V) at 50 ± 5 ° C for 1 hour and slowly warmed to 25 ± 5 ° C and stirred for 6 hours. The solid was collected by filtration and washed with IPA (2.1 L, 0.5 V). The wet solid (2.32 kg) was dried in a vacuum tray dryer at 40 ± 5 ° C to obtain about 2.13 kg of the compound of formula Ia.

[0143] Analytical data: Purity (HPLC): 98.4%

[0144] Purification of Compound of Formula Ib:

[0145] The crude compound of Formula Ib (2.94 kg) was stirred with IPA (8.8 L, 3.0 V) at 50±5° C. for 1 hour, and slowly warmed to 25±5° C. and stirred for 6 hours. The solid was collected by filtration and washed with IPA (2.9 L, 1.0 V).

[0146] The wet solid (1.53 kg (LOD corrected)) was stirred with ethyl acetate (4.6 L, 3.0 V) at 50 ± 5 ° C for 1 hour, and slowly warmed to 25 ± 5 ° C and stirred for 6 hours. The solid was collected by filtration and washed with ethyl acetate (1.5 L, 1.0 V).

[0147] The wet solid (1.07 kg) was stirred with ethyl acetate (4.6 L, 3.0 V) at 50 ± 5 ° C for 1 hour, and slowly warmed to 25 ± 5 ° C and stirred for 6 hours. The solid was collected by filtration and washed with ethyl acetate (1.5 L, 1.0 V).

[0148] The wet solid (0.85 kg) was stirred with ethyl acetate (1.7 L, 2.0 V) at 50 ± 5 ° C for 1 hour, and slowly warmed to 25 ± 5 ° C and stirred for 6 hours. The solid was collected by filtration and washed with ethyl acetate (0.4 L, 0.5 V). The wet solid (0.58 kg) was dried in a vacuum tray dryer at 40 ± 5 ° C to obtain about 0.335 kg of the compound of formula Ib.

[0149] Analytical data: Purity (HPLC): 99.5%

[0150] For a three-step synthesis of converting a compound of Formula Ia to a compound of Formula Ib, see Figure 5 .

[0151] Step 1: Opening of the lactone ring (compound of formula III)

[0152] A suspension of barium hydroxide octahydrate (1.16 kg, 1.0 eq) in methanol (10.3 L, 5.0 V) was cooled to 0-5° C. and the compound of Formula Ia (2.06 kg, 1.0 eq) was added in 4 equal portions at 0-5° C. over a period of 15 min. The resulting reaction mixture was stirred at 0-10° C. for 2 h (the reaction mass became homogeneous as the reaction proceeded). The product was visualized by TLC (60% ethyl acetate / hexane for starting material consumption, and 10% methanol / dichloromethane (MeOH / DCM) for product elution; visualization: KMnO 4 staining) to monitor the progress of the reaction.

[0153] Post-treatment: After complete consumption of the starting material by TLC, the reaction mixture was acidified to pH 5-6 using 10% aqueous acetic acid (about 8.24 L, 4.0 V) and concentrated at a temperature below 40° C. to remove methanol. The residue was extracted twice with (10.3 L*2, 5 V*2). The combined organic layer was washed with brine solution (8.2 L, 4.0 V), dried over anhydrous sodium sulfate, filtered and the organic layer was used as is in the next stage.

[0154] Analytical data: Purity (HPLC): 99.5%

[0155] Step 2: Oxidation (Compound of Formula IV)

[0156] To the stirred organic layer (compound of Formula III) was added a suspension of Dess-Martin periodinane (1.72 kg, 1.1 eq) in DCM (16.5 L, 8 V) at 0-5°C. The resulting reaction mixture (white suspension) was stirred at 10-15°C for 3 h. Visualization by TLC (5% MeOH / DCM + one drop of AcOH; KMnO 4 staining) to monitor the progress of the reaction.

[0157] Workup: After complete consumption (compound of formula III) by TLC, the reaction mixture was quenched with 20% sodium thiosulfate in purified water (20.6 L, 10 V) and stirred for 30 minutes (the reaction mass became clear and clear separation of the organic and aqueous layers was observed). The layers were separated and the aqueous layer was extracted with DCM (10.3 L, 5.0 V). The combined organic layers were washed with brine solution (10.3 L, 5.0 V), dried over anhydrous sodium sulfate and filtered. The organic layer was concentrated to a 10.0 volume level relative to the compound of formula Ia at less than 40° C. and used in the next stage as is.

[0158] Step 3: Cyclization (Compound of Formula Ib)

[0159] To the stirred organic layer of the compound of Formula IV was added N-(3-dimethylaminopropyl)-N′-ethylcarbodiimide hydrochloride (EDC.HCl) (0.702 kg, 1.0 eq) followed by diisopropylethylamine (DIPEA) (0.957 L, 1.5 eq) at 10±5°C over a period of 30 minutes. The resulting reaction mixture was stirred at 10±5°C for 2 h. The product was visualized by TLC (10% MeOH / DCM for starting material consumption, and 80% ethyl acetate / hexane for product elution; visualization: KMnO 4 staining) to monitor the progress of the reaction.

[0160] Workup: After complete consumption of the compound of Formula IV by TLC, the reaction mixture was quenched with water (20.6 L, 10.0 L), the layers were separated, and the aqueous layer was extracted with DCM (10.3 L, 5.0 V). The combined organic layers were washed with brine solution (10.3 L, 5.0 V), dried over anhydrous sodium sulfate and filtered. The combined organic layers were dried over anhydrous sodium sulfate and concentrated at 40° C. under reduced pressure until no distillate was observed.

[0161] Purification of the compound of formula Ib: The crude compound of formula Ib was driven out with ethyl acetate (12.3 L, 6.0 V) at less than 40 ° C, concentrated to 3.0 volume levels relative to the compound of formula Ib, and stirred at 50 ± 5 ° C for 1 hour. The reaction mass was gradually cooled to 25 ± 5 ° C for 1 hour and stirred at 25 ± 5 ° C for 6 hours. The solid was collected by filtration and washed with ethyl acetate (2.1 L, 1.0 V) to obtain 1.1 kg of wet solids of the compound of formula Ib. The wet solid was dried in a vacuum tray dryer at 40 ± 5 ° C to obtain 0.85 kg of the compound of formula Ib.

[0162] Analytical data: Purity (HPLC): 95.4%

[0163] Table 1: Residual solvents

[0164] Methanol NMT 3000ppm BDL Acetonitrile NMT 410ppm BDL acetone NMT 5000ppm BDL Dichloromethane NMT 2000ppm 2443 Hexane NMT 290ppm BDL Ethyl acetate NMT 10000ppm 4198 n-Heptane NMT 5000ppm BDL Isopropyl alcohol NMT 5000ppm BDL

[0165] BDL = below detection level, NMT = not exceeding

[0166] Synthesis of compounds of formula V from compounds of formula Ib

[0167] To a solution of the compound of Formula Ib (322 g, 1.0 eq.) in anhydrous dimethylformamide (DMF) (1.6 L, 5.0 V) was added 4-N,N-dimethylaminopyridine hydrochloride (DMAP.HCl) (91 g) followed by isobutyryl chloride (92 g, 1.5 eq) at 25±5°C. The reaction mass was heated to 60±5°C and stirred for 6 hours. After 6 hours, DMAP.HCl (45.6 g) was added to the reaction mass at 60±5°C followed by isobutyryl chloride (61.2 g, 1.0 eq) and the reaction was continued for another 4 hours. The reaction was monitored by HPLC.

[0168] Post-processing:

[0169] After the reaction was completed, the reaction mixture was cooled to 25±5°C, filtered through a celite bed, and washed with DMF (320 ml, 1.0 V). The filtrate was passed through a 0.2 micron column and washed with DMF (320 ml, 1.0 V).

[0170] Purified water (8.0 L, 25.0 V) was added to another reaction vessel and cooled to 15 ± 5 ° C. The filtrate was slowly added to the reaction contents at 15 ± 5 ° C over a period of 1 hour (reverse quenching). The reaction contents were brought to a temperature of 25 ± 5 ° C and stirred at the same temperature for 4 hours. The solid was collected by filtration and washed with purified water (0.65 L, 2.0 V).

[0171] The wet solid was stirred with purified water (1.6 L, 5 V) at 40 ± 5 ° C for 2 hours. The solid was collected by filtration and washed with purified water (0.65 L, 2 V). The wet solid was dried under reduced pressure at 40 ± 5 ° C for 12 hours to obtain 456 g of the crude product of Formula V (purity of crude material by HPLC: 79.97%)

[0172] Ethyl acetate purification:

[0173] Ethyl acetate slurry-1: The crude product (456 g) was stirred with ethyl acetate (1.36 L, 3.0 V) at 50 ± 5 ° C for 1 h. The reaction mass was gradually warmed to 25 ± 5 ° C for 1 hour and stirred at 25 ± 5 ° C for 4 h. The solid was collected by filtration and washed with ethyl acetate (0.45 L, 1.0 V). (Wet solid weight: 295 g, after loss on drying (LOD) correction: 249 g (LOD: 15.6% w / w)) (Purity by HPLC: 97.7%, and impurities: RRT 0.68: 1.38%)

[0174] Ethyl acetate slurry-2: The crude product (249 g) was stirred with ethyl acetate (373 ml, 1.5 V) at 50 ± 5 ° C for 1 h. The reaction mass was gradually warmed to 25 ± 5 ° C for 1 hour and stirred at 25 ± 5 ° C for 4 h. The solid was collected by filtration and washed with ethyl acetate (0.45 L, 1.0 V). (Wet solid weight: 236.6 g, after LOD correction: 230 g (LOD: 2.6% w / w)) (Purity by HPLC: 98.68%, and impurities: RRT 0.68: 1.38%)

[0175] Ethyl acetate slurry-3: The crude product (230 g) was stirred with ethyl acetate (460 ml, 2.0 V) at 50 ± 5 ° C for 1 h. The reaction mass was gradually warmed to 25 ± 5 ° C for 1 hour and stirred at 25 ± 5 ° C for 4 h. The solid was collected by filtration and washed with ethyl acetate (115 ml, 1.0 V). (Wet solid weight: 191.6 g, purity by HPLC: 99.8%, and impurities: RRT0.68: 0.12%)

[0176] The wet solid was dried under reduced pressure at 40±5°C for not less than (NLT) 10 hours to obtain 185.4 g of the crude compound of Formula V.

[0177] Purify acetone / purified water to obtain the desired monohydrate form:

[0178] The crude compound of formula V (181.4 g) was stirred with acetone (1.3 L, 7.0 V) at 45 ± 5 ° C for 30 minutes to obtain a clear solution. Purified water (2.8 L, 15.0 V) was added to the reaction mass over a period of 1 hour and stirred for another 1 hour at 45 ± 5 ° C. The reaction mass was gradually cooled to 25 ± 5 ° C and stirred for 6 hours. The solid was collected by filtration and washed with acetone / purified water (278 ml, 1.0 V) to obtain a wet product of 188 g of formula V monohydrate. The wet solid was dried under reduced pressure at 40 ± 5 ° C for NLT 16 hours, then sieved to obtain 179 g of the compound of formula V monohydrate.

[0179] Analytical data: Purity (HPLC): 99.9%

[0180] Table 2: Residual Solvents

[0181] Solvents limit result Methanol NMT 3000ppm BDL Acetonitrile NMT 410ppm BDL Toluene NMT 890 BDL acetone NMT 5000ppm BDL Dichloromethane NMT 600ppm BDL MTBE NMT 5000ppm BDL Hexane NMT 290ppm BDL Ethyl acetate NMT 5000ppm BDL n-Heptane NMT 5000ppm BDL DMF NMT 880ppm BDL Isopropyl alcohol NMT 5000ppm BDL

[0182] BDL = below detection level, NMT = not exceeding

[0183] Specific rotation: -49.8°

[0184] The IR spectrum of the resulting compound is seen at Figure 6 middle.

[0185] NMR data:

[0186] 1 H-NMR (DMSO, 400MHz): δ8.64(s,1H),7.78(s,1H),6.75(dd,1H),5.09(s, 1H),4.69(s,1H),3.92(s,1H),3.41(s,3H),2.68(m,3H),2.35(m,2H),2.2 4(m,3H),1.95(m,2H),1.67(m,1H),1.55(d,4H),1.42(s,3H),1.26(d,6H) ,1.18(m,1H),1.04(s,1H),0.76(s,3H)LCMS: 453.3[M+H], HPLC purity: 98.50%

[0187] It should be understood that although the present invention has been described in conjunction with the specific description of the present invention, the foregoing description is intended to illustrate rather than limit the scope of the present invention, and the scope of the present invention is defined by the scope of the appended claims. Other aspects, advantages and modifications are within the scope of the following claims.

[0188] References

[0189] EP 2807170

Claims

1. A method for obtaining at least one of the compounds of formula Ia and formula Ib wherein R1 is a linear, branched or cyclic alkyl group having 1 to 6 carbon atoms, which is unsubstituted or substituted, for example, by OH or halogen, such as F, the method comprising (i) providing a composition comprising: At least one of the compounds of formula IIa and formula IIb, in R1 is as defined above, R2 and R3 are independently selected from linear, branched or cyclic, substituted or unsubstituted alkyl groups having 1 to 6 carbon atoms or from nicotinoyl groups; and / or Provided is an extract composition from Entandrophragma caudatum comprising at least a compound of formula IIa, wherein c) R2 and R3 are independently selected from a linear or branched alkyl group having 1 to 6 carbon atoms or a nicotinyl group; and d) R1 is methyl; (ii) subjecting the extract composition and / or optionally the composition from step (i) to one or more distillations and introducing a solvent comprising an aliphatic alkanol; (iii) conducting an alkanolysis reaction by adding an aliphatic metal alkoxide in the presence of an aliphatic alcohol to initiate the reaction, and then adding an acid, preferably an organic acid such as acetic acid, to terminate the alkanolysis reaction, thereby obtaining at least one of the compounds of Formula Ia and Formula Ib.

2. The method according to claim 1, which is carried out using the extract composition of Endoandrum caudatum.

3. The method according to claim 1 or 2, wherein the extract composition of Endoandraceae caudatus comprises at least one of phragmalin-3,30-di-isobutyrate, phragmalin-3-isobutyrate-30-propionate, phragmalin-3-nicotinate-30-isobutyrate and / or a precursor of the compound of formula Ib.

4. The method according to any one of claims 1 to 3, further comprising removing polar impurities from the compounds of Formula Ia and Formula Ib by: a) removing the fatty alcohol; b) adding one or more polar extracting liquids, and optionally c) removing water by adding a water absorbing agent, for example selected from sodium sulfate, MgSO4, CaSO4, CaCl2, K2CO3, to obtain a crude mixture of the compounds.

5. The method according to any one of claims 1 to 4, further comprising removing non-polar impurities by dissolving the non-polar impurities in a water-immiscible solvent, and discarding the solvent phase with the non-polar impurities to obtain a crude mixture, wherein the water-immiscible solvent is preferably hexane or a solvent having a polarity index similar to that of hexane, such as pentane, cyclohexane, heptane.

6. A process according to claim 4 or 5, comprising concentrating the crude mixture obtained or obtainable by claim 5 and contacting the crude mixture at least once with the water-immiscible solvent according to claim 5, thereby obtaining a compound of formula Ia and / or formula Ib in solid form.

7. The process according to any one of claims 1 to 6, comprising the further step of chromatographically separating the compound of formula Ia from the compound of formula Ib, and further separately collecting and purifying the compounds of formula Ia and formula Ib, respectively, preferably wherein the final purity of each of the compounds is at least 90%.

8. A process according to any preceding claim, wherein the alkanolysis is a methanolysis reaction in a methanol solvent comprising the addition of a methoxide, preferably sodium methoxide.

9. A method for producing a compound of formula Ib from a compound of formula Ia, the method comprising: (i) reacting the compound of formula Ia with a base strong enough to open the lactone ring but not to hydrolyze the group R1 to form a carboxyl group, preferably the base is barium hydroxide octahydrate in methanol, to obtain a compound of formula III; (ii) reacting a compound of formula III with a selective oxidizing agent, preferably Dess-Martin periodinane, to obtain a compound of formula IV; as well as (iii) reacting a compound of formula IV with a coupling agent, preferably a carbodiimide coupling agent, such as 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride (EDC.HCl) in the presence of a sterically hindered organic base, preferably N,N-diisopropylethylamine (DIPEA), thereby obtaining a compound of formula Ib.

10. The process according to claim 9, wherein the compound of formula Ia is or is obtainable by a process according to any one of claims 1 to 6.

11. A process for producing a compound of formula V from a compound of formula Ib, said process being carried out by reacting a compound of formula Ib with an esterifying agent and a sterically hindered base to selectively introduce a group R2' of formula V, wherein R2′ is a linear, branched or cyclic optionally substituted alkyl group having 1 to 6 carbon atoms.

12. The process according to claim 11, wherein R2' is isopropyl and R1 is methyl, and wherein DMAP-HCl is used as the sterically hindered base and isobutyryl chloride is used as the esterifying agent.

13. The process according to claim 11 or 12, wherein the compound of formula Ib is obtained according to the process according to any one of claims 9 or 10.

14. The process according to any one of claims 11 to 13, further comprising continuously purifying the compound of formula V with a less polar solvent, preferably ethyl acetate and successively with a bipolar solvent, preferably acetone and water and mixtures thereof, thereby obtaining a solid monohydrate of the compound of formula V.

15. A compound of formula III.

16. The compound according to claim 15, wherein R1 is methyl.

17. A compound according to claim 15 or 16, which is obtainable or obtainable by the process of step (i) of claim 9.

18. A compound of formula IV.

19. The compound according to claim 18, wherein R1 is methyl.

20. A compound according to claim 18 or 19, which is obtainable or obtainable by the process of step (ii) of claim 9.

21. A monohydrate salt of a compound according to formula V, wherein R1 is preferably methyl.

22. A compound according to formula V, provided that R1 is not hydrogen, methyl or ethyl.

23. An extract composition of Endoandrum caudatum prepared from the seeds of Endoandrum caudatum, the extract composition of Endoandrum caudatum comprising at least one of a compound according to Formula IIa and a precursor of Formula Ib, wherein the extract composition of Endoandrum caudatum is produced by: (i) mixing ground seeds of Echinops caudatus with methanol, filtering, collecting and concentrating to obtain a concentrated methanol extract; (ii) mixing the concentrated methanol extract with a less polar solvent and a more polar solvent to obtain a two-phase composition, and discarding the polar solvent phase to eliminate polar impurities and concentrating the less polar solvent phase, preferably by distillation, thereby obtaining the extract composition of Endoandromeda caudatus.

24. The extract composition according to claim 23, wherein the less polar solvent in step (ii) forms an azeotrope with water, preferably the less polar solvent comprises ethyl acetate and the polar solvent comprises water.

25. The extract composition according to claim 24, wherein the less polar solvent and the more polar solvent in step ii) are ethyl acetate and water, respectively, in a volume ratio of 2:

1.

26. The extract composition according to any one of claims 23 to 25, comprising at least one of the compounds phragmalin-3,30-di-isobutyrate, phragmalin-3-isobutyrate-30-propionate and phragmalin-3-nicotinate-30-isobutyrate.

27. A method for producing an extract composition of Endoandrum caudatum prepared from the seeds of Endoandrum caudatum, the extract composition of Endoandrum caudatum comprising at least one of the compound according to Formula IIa and / or the precursor of Formula Ib, the method comprising the following steps: i) mixing ground seeds of Echinops caudatus with methanol, filtering, collecting and concentrating to obtain a concentrated methanol extract; ii) mixing the concentrated methanol extract with a less polar solvent and a more polar solvent to obtain a two-phase composition, and discarding the more polar solvent phase to eliminate polar impurities and concentrating the less polar solvent phase, preferably by distillation, thereby obtaining the extract composition of Endoandromeda caudatus.

28. The process of claim 27, wherein the less polar solvent in step (ii) forms an azeotrope with water, preferably the less polar solvent comprises ethyl acetate and the more polar solvent comprises water.

29. The method according to claim 27 or 28, wherein the solvent with less polarity and the solvent with greater polarity in step ii) are ethyl acetate and water, respectively, in a volume ratio of 2:

1.

30. A method for producing the compound of formula VI 9R,15S,16S,17S,18S-4-(furan-3-carbonyl)-15-hydroxy-18-(2-methoxy-2-oxoethyl)-4,12,17,19-tetramethyl-7-oxo-8,11,13,20-tetraoxacyclo[10.7.1.114,17.01,10.05,10.09,15.014,19]heneicosane-16-yl 2-methylpropanoate monohydrate The method comprises the following steps: (i) using the method according to any one of claims 1 to 8 to obtain at least one of the compound of formula Ia wherein R1 is methyl and the compound of formula Ib wherein R1 is methyl; (ii) collecting the compound of formula Ia separately and converting it into a compound according to formula Ib using the method according to claim 9; as well as (iii) converting the compound according to formula Ib collected from steps (i) and (ii) using a process according to claim 11 or 12 to obtain a compound of formula lib, wherein R2 is isopropyl.

31. The process according to claim 30, further comprising obtaining a monohydrate of the compound according to formula VI by carrying out the process according to claim 14.

32. The method according to claim 30 or 31, wherein the starting material in step i) is the extract composition of Endoandrum caudatum according to any one of claims 27 to 29.

33. A process for obtaining at least one of the compounds of formula Ia and Ib, said process comprising carrying out a process according to claims 27 to 29 followed by a process according to any one of claims 1 to 8.

34. The process according to claim 33, further comprising obtaining a compound of formula V by carrying out the process according to claims 11 to 14.

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