Process for producing 4-hydroxyacetophenone

Abstract

A process for producing 4-hydroxyacetophenone (4-HAP) comprises the steps of providing phenyl acetate; charging the phenyl acetate and anhydrous hydrogen fluoride (HF) in a reactor; and allowing the mixture of the phenyl acetate and the HF to react under conditions suitable for forming 4-HAP by Fries rearrangement. Process for recovery of 4-HAP, comprising:providing a 4-HAP containing phase;extracting the 4-HAP from the 4-HAP containing phase into a first organic solvent, preferably ethyl acetate, phase;evaporating the first organic solvent, preferably ethyl acetate, from the 4-HAP containing first organic solvent, preferably ethyl acetate, phase; subsequently, recrystallizing the 4-HAP from water; and optionally, recrystallizing the 4-HAP from a heptane phase before the recrystallization from water.

Description

[0001] Process for producing 4-hydroxyacetophenone

[0002] The present invention lies in the field of cosmetics and, more specifically, concerns a process for the production of 4-hydroxyacetophenone (4-HAP).

[0003] 4-hydroxyacetophenone (4-HAP) is a well-known large scale organic synthesis intermediate used in many life sciences syntheses including one of the industrial processes for paracetamol. A process for producing crude 4-HAP is known from EP 0 167 286 A1. In this process, phenol is acetylated to 4-HAP by contacting phenol with acetic acid or acetic anhydride. When acetic acid is the acetylating agent, per mole of phenol about 0.9 to 1 .4 moles of acetic is used in the presence of about 20 to 50 moles of hydrogen fluoride, at a temperature of reaction of about 40 to 90°C, for a reaction period of about 10 to 120 minutes. When acetic anhydride is the acetylating agent, per mole of phenol, about 0.9 to 2.0 moles of acetic anhydride is used, in the presence of about 8 to 60 moles of hydrogen fluoride (HF), at a temperature of reaction of about 30 to 95°C for a reaction period of at least about 10 minutes. The process is said to result in a phenol conversion of at least about 80% and a reaction selectivity to crude 4-HAP of at least about 70%.

[0004] As a drawback of the known process, the applicant observed that 90-94 % of the large HF excess can be recycled by distillation. However, 1 .2 to 2 equivalents of HF remain complexed in the crude product and cannot be recycled by means of distillation. Even at p < 3 mbar, the required temperature leads to decomposition / polymerization of the crude product. This prevents the full recovery of HF, and requires its neutralization by about 2 equivalents potassium hydroxide (KOH), which in turn, has a significant cost impact. Furthermore, recycling of the resulting mixture of potassium acetate (KOAc) and potassium fluoride (KF) is difficult and elaborate. Moreover, to achieve the quality and the olfactory specifications of cosmetic grade 4-HAP, crude 4-HAP has to undergo further purification. The object to be solved by the present invention is the provision of a process for producing 4-HAP that overcomes at least some advantages of the known process. In particular, it was the aim to circumvent the cost impact associated with the requirement of neutralization of HF using KOH and to obtain pure KF as recyclable byproduct without KOAc contamination.

[0005] This object is achieved by a process as set forth in appended claim 1 . The dependent claims define specific embodiments of the invention.

[0006] According to the present invention, the process for the production of 4-HAP is based on Fries rearrangement of phenyl acetate in (anhydrous) HF. It comprises the steps of: a) providing phenyl acetate and HF; b) feeding the phenyl acetate and the HF into a reactor; and c) allowing the mixture of the phenyl acetate and the HF (herein also referred to as “reaction mixture’") to react under conditions suitable for forming 4-HAP by Fries rearrangement.

[0007] The formation of 4-HAP by Fries rearrangement follows reaction scheme (I):

[0008] A number of advantages are associated with the Fries rearrangement of phenyl acetate in HF. In particular, the Fries rearrangement leads to (a) more complete HF recycling (which in turn decreases KOH consumption), (b) increased yield (referred to Fries-rearrangement), and (c) easier work-up because the only byproduct is KF, which is easy to recycle, whereas a mix of KOAc / KF (difficult to recycle) occurs as byproduct in the known process.

[0009] In certain embodiments, the process is carried out batch-wise, e.g., in a batch reactor. In other embodiment, the process is carried out continuously, e.g., using a flow reactor. A reason for a batch process is its simplicity. However, on large-scale production, a batch process would require handling of large amounts of anhydrous HF in large excess, which is often not feasible. This drawback can be overcome by a continuous process.

[0010] Preferably, the HF is fed into the reactor at a temperature ranging from -30°C to -15°C, in particular at a temperature ranging from -25°C to -20°C. The Fries rearrangement can be initiated by and / or conducted at a temperature ranging from 30°C to 60°C, preferably at a temperature ranging from 35°C to 50°, more preferably at a temperature ranging from 40°C to 45°C. At elevated temperatures above 60°C, in turn, the formation of 2-HAP as byproduct increases.

[0011] In a preferred embodiment, the phenyl acetate is produced by acetylation of phenol with acetic anhydride so that the overall reaction follows reaction scheme (II):

[0012] Accordingly, when starting from phenol, the production of 4-HAP in accordance with the process of the invention involves two basic steps, namely, first, the acetylation of phenol and, second, the Fries-rearrangement of the phenyl acetate. Both steps are temporally, and optionally spatially, separated from each other.

[0013] In a preferred embodiment, the 4-HAP and / or the phenyl acetate is / are substantially non- petrochemical. A compound is considered “substantially non-petrochemical” herein, if at least 75 %, preferably at least 80 %, further preferably at least 85 %, particularly preferably at least 90 %, even further preferably at least 95 %, more preferably at least 97.5 % of its carbon is non- petrochemically-derived carbon, based on the total carbon content of the respective compound. Particular preferred is that the 4-HAP and / or the phenyl acetate is / are non-petrochemical, i.e. all carbon of the respective compound is non-petrochemically-derived carbon, based on the total carbon content of the respective compound.

[0014] Methods for determining whether and which proportion of the carbon of a compound is petrochemically-derived and / or non-petrochemically-derived are known to a skilled person. In the framework of the present invention radiocarbon dating is preferably used. Typically, the radiocarbon dating provides a proportion of 14C in a sample, wherein this proportion represents the percentage of 14C based on the total carbon content in the sample. 14C represents the non- petrochemically-derived carbon. Accordingly, if the 4-HAP and / or the phenyl acetate is / are substantially non-petrochemical as determined according to radiocarbon dating, this may mean that the proportion of 14C in the compound is at least 75 %, preferably at least 80 %, further preferably at least 85 %, particularly preferably at least 90 %, even further preferably at least 95 %, more preferably at least 97.5 %.

[0015] Non-petrochemical phenyl acetate can, for example, be produced from non-petrochemical phenol, following the above-mentioned route. Sources of non-petrochemical phenol are cyclic terpenes and terpenoids. Non-petrochemical phenol can be produced from lignocellulose-derived alkylmethoxyphenols.

[0016] In other embodiments, the 4-HAP is substantially petrochemical. A compound is considered “substantially petrochemical” herein, if at least 75 %, preferably at least 80 %, further preferably at least 85 %, particularly preferably at least 90 %, even further preferably at least 95 %, more preferably at least 97.5 % of its carbon is petrochemically-derived carbon, based on the total carbon content of the respective compound. In this embodiment, it is particularly preferred that the 4-HAP and / or the phenyl acetate is / are petrochemical, i.e. all carbon of the respective compound is petrochemically-derived carbon, based on the total carbon content of the respective compound.

[0017] Envisaged is further a mixture of petrochemical and non-petrochemical phenyl acetate and / or a mixture of petrochemical and non-petrochemical 4-HAP.

[0018] In a further preferred embodiment of the present invention, after formation of the 4-HAP, the HF is recovered from the reaction mixture by distillation of the HF. Distillation may be performed at a temperature ranging from 30°C to 50°C, leaving a 4-HAP containing residue as remainder. The advantage of the distillation step is that the HF gas can be easily recycled, if desired. Alternatively or additionally, HF can be removed by flushing with nitrogen. That is, the reaction mixture is flushed with nitrogen to remove HF therefrom, or, if distillation of the 4-HAP has been carried out, the residue is flushed to remove even more HF therefrom. Expressions like “remove the HF", as used herein, are not to be understood to require a complete removal of the HF, but are rather to be understood to encompass any reduction of the amount of the HF.

[0019] A further preferred embodiment of the process involves - after formation of the 4-HAP and, if present, after recovery and / or removal of the HF - recovery of the 4-HAP from the reaction mixture or the residue by extraction and / or crystallization. Preferably, the recovery of the 4-HAP involves extracting the 4-HAP into a first organic solvent, preferably ethyl acetate, phase. To this end, the reaction mixture orthe residue can be brought into contact with the first organic solvent, preferably ethyl acetate, and be rigorously mixed. Thereby, the 4-HAP is enriched in the first organic solvent, ethyl acetate, phase, which can be recovered by phase separation. The 4-HAP can then be crystallized from the first organic solvent, preferably ethyl acetate, phase. After removal of the supernatant (mainly the first organic solvent, preferably ethyl acetate), the crude product can further be recrystallized from a second organic solvent different from the first organic solvent, e.g., heptane, and / or water, and / or can be further dried.

[0020] It is particularly preferred that the 4-HAP is recrystallized from water that contains 4-HAP in an amount of 10 to 20 wt.-%, preferably in an amount of 10 to 18 wt.-%, more preferably in an amount of 10 to 16 wt.-%. This is because recrystallization from water in higher dilution (e.g., 10 to 20 wt.- %) leads to higher purity and less discoloration compared to double recrystallization from organic solvent (e.g., heptane) and water and as compared to recrystallization from water in lower dilution (e.g., 25 to 35 wt.-%). That is, the lower the 4-HAP amount, the better the purity and coloration. If the recrystallization of 4-HAP is conducted at a concentration of 10 wt.-%, no further recrystallization step is required.

[0021] It is further preferred that, prior to the recovery of the 4-HAP from the reaction mixture, the pH of the reaction mixture or the residue is set to between 5 and 7. If the pH is 8 or higher, 4-HAP will dissolve better in aqueous phase than in organic phase. For instance, the Fries rearrangement reaction can be quenched by addition of water. The water may be added at a pH that results in the desired pH value, or the pH value is set after addition of the water. The pH values is preferably set with KOH.

[0022] A further aspect pertains to 4-HAP, preferably produced by the process as described herein. Preferably, the 4-HAP is substantially non-petrochemical, more preferably non-petrochemical. The 4-HAP may be contained in a product or composition, preferably a personal care product or composition, or a pharmaceutical product or composition.

[0023] Another aspect of the present invention concerns a process for recovery and / or purification of 4- HAP from a 4-HAP containing phase. The process comprises the following steps: (i) providing a 4-HAP containing phase; (ii) extracting the 4-HAP from the 4-HAP containing phase into an ethyl acetate phase; (iii) evaporating the ethyl acetate from the 4-HAP containing ethyl acetate phase; (iv) subsequently, recrystallizing the 4-HAP from water; and (v) optionally, recrystallizing the 4- HAP from a heptane phase before the recrystallization from water. This process results in recovery of 4-HAP in high purity.

[0024] This process differs from that known from WO 2022 / 096755 in several aspects. The core of the prior art process is crystallization of 4-HAP from a solution of ethanol and ethyl acetate upon cooling, whereas the present invention resides on recrystallization from water. Further, WO 2022 / 096755 neither mentions extraction of 4-HAP into an ethyl acetate phase, nor describes an intermediate evaporation of ethyl acetate. Experiments

[0025] 1 . Synthesis of phenyl acetate

[0026] Phenyl acetate (PhOAc) synthesis was carried out by reacting phenol with acetic anhydride (Ac2O) in the presence of 10 mol% sodium acetate (NaOAc). To this end, phenol (50 g, 0.52 mol, 1 .0 eq) was charged at 70 °C to the reactor. NaOAc (5.0 g, 60 mmol, 0.11 eq) was added and the mixture heated up to 100 °C. Then Ac2O (68 g, 0.67 mol, 1.3 eq) was added dropwise over a period of 120 min. After complete addition, the reaction mixture was stirred for another 7 h at 100 °C. The conversion of Phenol was monitored by TLC. After reaction was complete, crude phenyl acetate was purified from the reaction mixture by removing acetic acid (AcOH) using distillation at 70°C and extraction using water and ethyl acetate (EtOAc). Specifically, AcOH (40 g) was distilled off at 70 °C and 15 mbar. Crude product was cooled to room temperature, diluted with water (50 g) and extracted with EtOAc (100 g). After phase separation, the organic layer was washed with aqueous NaOH (50 g, 2 %) and water (50 g). The solvent (82 g EtOAc) was removed at 70 °C and 20 mbar to yield PhOAc (66.9 g, 98 % purity, 0.48 mol, 92.5 % yield).

[0027] 2. Fries rearrangement to 4-HAP

[0028] 1 eq crude phenyl acetate from step 1 was charged into 20eq HF, and the reaction was allowed to proceed at 40°C for 1 h. Unreacted HF was distilled at 50°C over 2h for recovery. Residual HF was purged by nitrogen for 2h, and neutralized with 0.13 eq KOH 50%.

[0029] 3. Examples

[0030] 3.1 Example 1

[0031] Anhydrous HF (145 g, 7.28 mol, 20 eq) was charged to a 0.5 L autoclave at -20 to -25 °C. Phenyl acetate (50 g, 0.368 mol, 1 eq) was added at -15 to -10 °C. The reaction mass was heated under stirring at 40 °C for 1 h. Conversion was monitored by GC. HF (132 g, 91 %) was distilled off at 40 °C over 2 h, and could be recycled for the next batch. The residual crudes (59 g) were transferred by N2 flushing to a plastic beaker. Water (100 g) and KOH solution (37.8 g, 48 % in water, 0.32 mol, 0.89 eq) were added to adjust the pH to 6-6.5 at 5-10 °C. The aqueous phase was extracted with EtOAc (100 g) and the organic phase was washed with water (50 g). The combined organic layers were extracted with EtOAc (30 g) and the solvents of all combined organic layers (181 g) were removed (50 °C, 30 mbar, 30 min). After drying (40 °C, 20 mbar), Ethyl acetate (121 g, 93 %) was obtained, as well as crude product (57 g). The crude product was recrystallized (30 min at 90 °C and then 60 min at 25 °C) from water (400 g). The solids were washed with water (50 g) at 25 °C and then dried (50 °C, 30 mbar) to yield 4-HAP (46,5 g, 0.341 mol, 93.6 % or 87.3 % ref to Phenol). 3.2 Example 2

[0032] Anhydrous HF (289 g, 14.45 mol, 20 eq) was charged to a 0.5 L autoclave at -20 to -25 °C. Phenyl acetate (100 g, 0.73 mol, 1 eq) was added at -15 to -10 °C. The reaction mass (389 g) was heated under stirring at 40 °C for 1 h. Conversion was monitored by HPLC. HF (270 g, 93 %) was distilled off at 40 °C over 2 h and could be recycled for the next batch. The residual crudes (1 18 g) were transferred by N2 flushing (3 h) to a plastic beaker. Water (100 g) and KOH solution (9 g, 48 % in water, 0.08 mol, 0.11 eq) were added to adjust pH to 6-6.5 at 5-10 °C. The aqueous phase was extracted with EtOAc (200 g) and the organic phase was washed with water (100 g). The solvents of all combined organic layers (297 g) were removed (50 °C, 30 mbar, 40 min). After drying (40 °C, 20 mbar), Ethyl acetate (179 g, 89.5 %) was obtained, as well as crude product (102 g). The crude product was recrystallized (30 min at 90 °C and then slowly cooled to 25 °C) from heptane (200 g). After filtration, the solids were washed with heptane (50 g). Parts of the applied heptane (193 g, 77 %) could be redistilled. The obtained solids were recrystallized (30 min at 90 °C and then 60 min at 10 °C) from water (200 g). The solids were washed with water (50 g) at 25 °C and then dried (50 °C, vacuum) to yield 4-Hydroxy acetophenone (92.60 g, 0.678 mol, 93 %).

[0033] 3.3 Example 3

[0034] Anhydrous HF (288 g, 14.4 mol, 20 eq) was charged to a 0.5 L autoclave at -20 to -25 °C. Phenyl acetate (100 g, 0.73 mol, 1 eq) was added at -15 to -10 °C. The reaction mass (388 g) was heated under stirring at 40 °C for 1 h. Conversion was monitored by HPLC. HF (271 g, 94 %) was distilled off at 40 °C over 2 h and could be recycled for the next batch. The residual crudes (1 15 g) were transferred by N2 flushing (3 h) to a plastic beaker. Water (100 g) and KOH solution (8 g, 48 % in water, 0.07 mol, 0.09 eq) were added to adjust pH to 6-6.5 at 5-10 °C. The aqueous phase was extracted with EtOAc (200 g) and the organic phase was washed with water (100 g). The solvents of all combined organic layers (299 g) were removed (50 °C, 30 mbar, 40 min). After drying (40 °C, 20 mbar), ethyl acetate (175 g, 87.5 %) was obtained, as well as crude product (100 g). The crude product was recrystallized (30 min at 90 °C and then slowly cooled to 25 °C) from heptane (200 g). After filtration, the solids were washed with heptane (50 g). Parts of the applied heptane (183 g, 73 %) could be redistilled. The obtained solids were recrystallized (30 min at 90 °C and then 60 min at 10 °C) from water (200 g). The solids were washed with water (50 g) at 25 °C and then dried (50 °C, vacuum) to yield 4-HAP (91 .80 g, 0.671 mol, 92 %).

[0035] 3.4 Example 4 (comparative example)

[0036] Anhydrous HF (325 g, 16.3 mol, 20 eq) was charged to a 0.5 L autoclave at -20 to -25 °C. Phenol (78.0 g, 0.82 mol, 1 eq) and acetic anhydride (83.76 g, 0.82 mol, 1 eq) were added at -15 to - 10 °C. The reaction mass (487 g) was heated under stirring at 40 °C for 2 h. Conversion was monitored by HPLC. HF (299 g, 92 %) was distilled off at 40 °C over 2 h and could be recycled forthe next batch. The residual crudes (140 g) were transferred by N2 flushing to a plastic beaker. Water (270 g) and KOH solution (178 g, 48 % in water, 1 .53 mol, 1 .86 eq) were added to adjust the pH to 6-6.5 at 5-10 °C. The aqueous phase was extracted with EtOAc (270 g) and the organic phase was washed with water (100 g). The combined organic layers were extracted with EtOAc (100 g) and the solvents of all combined organic layers (369 g) were removed (50 °C, 30 mbar, 30 min). After drying (40 °C, 20 mbar), ethyl acetate (345 g, 93 %) was obtained, as well as crude product (103 g). The crude product was recrystallized (30 min at 90 °C and then 60 min at 25 °C) from water (400 g). The solids were washed with water (50 g) at 25 °C and then dried (50 °C, 30 mbar) to yield 4-HAP (96.0 g, 0.703 mol, 85.7 %).

[0037] 3.5 Example 5 (comparative example)

[0038] Anhydrous HF (250 g, 12.5 mol, 20 eq) was charged to a 0.5 L autoclave at -20 to -25 °C. Phenol (60 g, 0.63 mol, 1 eq) and acetic anhydride (65 g, 0.64 mol, 1 eq) were added at -15 to -10 °C. The reaction mass (375 g) was heated under stirring at 40 °C for 2 h. Conversion was monitored by HPLC. HF (224 g, 90 %) was distilled off at 40 °C over 2 h and could be recycled for the next batch. The residual crudes (140 g) were transferred by N2 flushing to a plastic beaker. Water (200 g) and KOH solution (158 g, 48 % in water, 1.35 mol, 2.15 eq) were added to adjust pH to 6-6.5 at 5-10 °C. The aqueous phase was extracted with EtOAc (200 g) and the organic phase was washed with water (100 g). Combined aqueous layers were washed with EtOAc (100 g). The solvents of all combined organic layers were removed (50 °C, 30 mbar, 40 min). After drying (40 °C, 20 mbar), Ethyl acetate (272 g, 90 %) was obtained, as well as crude product (81 g). The crude product was recrystallized (30 min at 90 °C and then 60 min at 25 °C) from water (200 g). The solids were washed with water (50 g) at 25 °C and then dried (50 °C, vacuum) to yield 4-HAP (75.9 g, 0.548 mol, 87 %).

[0039] 3.6 Example 6 (comparative example)

[0040] Anhydrous HF (250 g, 12.5 mol, 20 eq) was charged to a 0.5 L autoclave at -20 to -25 °C. Phenol (60 g, 0.63 mol, 1 eq) and acetic anhydride (65 g, 0.64 mol, 1 eq) were added at -15 to -10 °C. The reaction mass (375 g) was heated under stirring at 40 °C for 2 h. Conversion was monitored by HPLC. HF (228 g, 91 %) was distilled off at 40 °C over 2 h and could be recycled for the next batch. The residual crudes (138 g) were transferred by N2 flushing to a plastic beaker. Water (200 g) and KOH solution (152 g, 48 % in water, 1.30 mol, 2.06 eq) were added to adjust pH to 6-6.5 at 5-10 °C. The aqueous phase was extracted with EtOAc (200 g) and the organic phase was washed with water (100 g). Combined aqueous layers were washed with EtOAc (100 g). The solvents of all combined organic layers were removed (50 °C, 30 mbar, 40 min). After drying (40 °C, 20 mbar), Ethyl acetate (275 g, 92 %) was obtained, as well as crude product (80.5 g). The crude product was recrystallized (30 min at 90 °C and then 60 min at 25 °C) from heptane (150 g). After washing the solids with heptane (50 g) and redistillation, parts of the heptane (194 g, 78 %) could be recycled. The crude product (74 g) was recrystallized (30 min at 90 °C and then 60 min at 25 °C) from water (200 g). The solids were washed with water (50 g) at 25 °C and then dried (50 °C, vacuum) to yield 4-HAP (72.0 g, 0.529 mol, 84 %).

[0041] 4. Results

[0042] The results are summarized in the following table:

[0043] Example starting material Crystallization required recycled recycled yield rxn yield ref KOH [eq] HF EtOAc to PhOH

[0044] 1 PhOAc Recryst. from water c 11 wt-% 0,89 91% 93% 93,60% 87,30%

[0045] 2 PhOAc 1st recryst. heptane, 2nd recryst. water c 32 wt.-% 0,11 93% 90% 93,20% 86,20%

[0046] 3 PhOAc 1st recryst. heptane, 2nd recryst. water c 32 wt.-% 0,09 94% 88% 92,20% 85,30%

[0047] 4 PhOH / Ac2O Recryst. from water c 19 wt.-% 1 ,86 92% 93% 85,70% 85,70%

[0048] 5 PhOH / Ac2O Recryst. from water c 28 wt.-% 2,15 90% 90% 86,70% 86,70%

[0049] 6 PhOH / Ac2O 1st recryst. heptane, 2nd recryst. water c 26 wt.-% 2,06 91% 92% 83,70% 83,70%

Claims

Claims1 . Process for producing 4-hydroxyacetophenone (4-HAP) comprising: a) providing phenyl acetate and anhydrous hydrogen fluoride (HF); b) feeding the phenyl acetate and the anhydrous hydrogen fluoride (HF) into a reactor; and c) allowing the phenyl acetate and the HF to react under conditions suitable for forming 4-HAP by Fries rearrangement to yield a 4-HAP containing phase.

2. Process of claim 1 , wherein the process is carried out batch-wise, continuous or semi- continuous, and / or wherein the reactor is a flow reactor or a batch reactor.

3. Process of claim 1 or 2, wherein the phenyl acetate and / or the 4-HAP is / are substantially petrochemical, or substantially non-petrochemical.

4. Process of any of the preceding claims, wherein the HF is charged into the reactor at a temperature ranging from -30°C to -15°C, preferably from -25°C to -20°C.

5. Process of any of the preceding claims, wherein step c) involves heating the mixture to 30 to 60°C, more preferably to 35 to 50°C, most preferably 40 to 45°C.

6. Process of any of the preceding claims, wherein step a) comprises preparing the phenyl acetate by acetylation of phenol using acetic anhydride.

7. Process of any of the preceding claims, wherein, after formation of the 4-HAP, the HF is recovered from the 4-HAP containing phase by distillation of the HF.

8. Process of any of the preceding claims, wherein, after formation of the 4-HAP and, if present, after recovery of the HF, the HF is removed from the 4-HAP containing phase by flushing with nitrogen.

9. Process of any of the preceding claims, wherein, after formation of the 4-HAP and, if present, after recovery and / or removal of the HF, the 4-HAP is recovered from the 4-HAP containing phase by extraction and / or evaporation and / or recrystallization.

10. Process of claim 9, wherein the recovery of the 4-HAP involves extracting the 4-HAP into a first organic solvent, preferably ethyl acetate, phase, preferably wherein the recovery ofthe 4-HAP further involves evaporating the first organic solvent, preferably ethyl acetate, from the 4-HAP containing first organic solvent, preferably ethyl acetate, phase.11 . Process of claim 9 or 10, wherein the recovery of the 4-HAP involves recrystallizing 4-HAP from a second organic solvent other than the first organic solvent and / or from water; and / or wherein the recovery of the 4-HAP involves recrystallizing 4-HAP from water containing 4- HAP in an amount of 10 to 20 wt.-%, preferably 10 to 18 wt.-%, preferably 10 to 16 wt.-%.

12. Process of any of claims 9 to 11 , wherein prior to the recovery of the 4-HAP, the pH of the 4-HAP containing phase is set to between 5 and 7.

13. 4-HAP, preferably produced by the process of any of claims 1 to 12, which is substantially petrochemical or substantially non-petrochemical.

14. Product or composition comprising 4-HAP according to claim 13, preferably wherein the product or composition is a personal care product or composition, or a pharmaceutical product or composition.

15. Process for recovery of 4-HAP, comprising: providing a 4-HAP containing phase; extracting the 4-HAP from the 4-HAP containing phase into a first organic solvent, preferably ethyl acetate, phase; evaporating the first organic solvent, preferably ethyl acetate, from the 4-HAP containing first organic solvent, preferably ethyl acetate, phase; subsequently, recrystallizing the 4-HAP from water; and optionally, recrystallizing the 4-HAP from a heptane phase before the recrystallization from water.

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