Compositions comprising hydroquinone and catechol, method for preparing these compositions
The present invention describes compositions comprising at least one compound chosen from hydroquinone and catechol, characterised in that it further comprises between 0.1 and 10,000 ppm of at least one compound chosen from 2-(alkoxy)phenol, 4-(alkoxy)phenol, 2-(alkyl)phenol, 4-(alkyl)phenol, (alkyl)catechol and (alkyl)hydroquinone. Another aspect of this invention concerns a method for preparing a composition comprising at least one compound chosen from hydroquinone and catechol according to the invention, characterised in that it comprises a step (a) of reacting the phenol with hydrogen peroxide in the presence of a catalyst, in a solvent comprising an alcohol.
1. A composition, comprising:
at least one compound selected from the group consisting of hydroquinone and catechol, and between 0.1 and 10,000 ppm of at least one compound selected from the group consisting of
2-(alkoxy)phenols, 4-(alkoxy)phenols, 2-(alkyl)phenols, 4-(alkyl)phenols, (alkyl)catechols, (alkyl)hydroquinones, and alkoxybenzenes, wherein the alkoxy is selected from the group consisting of tert-butoxy 2,2-dimethylpropoxy and isopropoxy and the alkyl is selected from the groups consisting of tert-butyl, 2,2-dimethylpropyl and isopropyl.
2. The composition as claimed in claim 1 , wherein the composition comprises at least 80% of hydroquinone and between 0.1 and 1000 ppm of at least one compound selected from the group consisting of 2-(alkoxy)phenols, 4-(alkoxy)phenols, (alkyl)catechols, and (alkyl)hydroquinones.
3. The composition as claimed in claim 1 , wherein the composition comprises at least 80% of catechol and between 0.1 and 1000 ppm of at least one compound selected from the group consisting of 2-(alkyl)phenols and 4-(alkyl)phenols.
4. The composition as claimed in claim 1 , wherein the at least one compound selected from the group consisting of 2-(alkoxy)phenols, 4-(alkoxy)phenols, 2-(alkyl)phenols, 4-(alkyl)phenols, (alkyl)catechols, (alkyl)hydroquinones, and alkoxybenzenes comprises at least one of 2-(tert-butoxy)phenol, 4-(tert-butoxy)phenol, 2-(tert-butyl)phenol, 4-(tert-butyl)phenol, (tert-butyl)catechol, (tert-butyl)hydroquinone and tert-butoxybenzene.
5. The composition as claimed in claim 1 , wherein the at least one compound selected from the group consisting of 2-(alkoxy)phenols, 4-(alkoxy)phenols, 2-(alkyl)phenols, 4-(alkyl)phenols, (alkyl)catechols, (alkyl)hydroquinones, and alkoxybenzenes comprises at least one of 2-(isopropoxy)phenol, 4-(isopropoxy)phenol, 2-isopropylphenol, 4-isopropylphenol, isopropylcatechol, isopropylhydroquinone and isopropylbenzene.
6. A process for the preparation of a composition according to claim 1 , comprising:
(a) reacting phenol with hydrogen peroxide in the presence of a catalyst, in a solvent consisting of an alcohol, or a mixture of alcohols or water and an alcohol or a mixture of alcohols, wherein the alcohol or mixture of alcohols is selected from the group consisting of isopropanol, 2,2-dimethylpropanol, tert-butanol, and mixtures thereof.
7. The process as claimed in claim 6 , further comprising:
(b) purifying the composition obtained in step (a).
8. The process as claimed in claim 7 , wherein the composition comprises hydroquinone and catechol, further comprising:
(a) separating hydroquinone and catechol, and, optionally:
(b) shaping the hydroquinone and catechol obtained in step (c).
9. The process as claimed in claim 6 , wherein the catalyst is a heterogeneous catalyst.
10. The process of claim 8 , wherein the process comprises step (d) and the products obtained in step (d) are in the form of a crystalline or amorphous powder.
11. The process of claim 9 , wherein the heterogeneous catalyst is a titanium-comprising zeolite.
12. The process of claim 9 , wherein the heterogeneous catalyst is a TS-1, TS-2, Ti-MWW, or Ti-MCM68 zeolite.
13. The process of claim 9 , wherein the heterogeneous catalyst is a TS-1 zeolite.