Improved two phase chemical reactions (liquid-liquid or liquid-gas) are provided by forming microdroplets of either or both liquid reagents and configuring the reaction as a collision between the microdroplet reagent and the other reagent. We have found that this approach can provide high reaction yields in short times (<1 s) without the use of a phase transfer catalyst.

Improved two phase chemical reactions (liquid-liquid or liquid-gas) are provided by forming microdroplets of either or both liquid reagents and configuring the reaction as a collision between the microdroplet reagent and the other reagent. We have found that this approach can provide high reaction yields in short times (<1 s) without the use of a phase transfer catalyst.

Processes for manufacturing a purified aromatic carboxylic acid include oxidizing a substituted aromatic compound in a reaction zone to form a crude aromatic carboxylic acid and a gaseous stream; heating the crude aromatic carboxylic acid in a pre-heating zone, contacting the crude aromatic carboxylic acid with hydrogen in the presence of a catalyst in a hydrogenation reactor to form a purified aromatic carboxylic acid, crystallizing the purified aromatic carboxylic acid in a crystallization zone to form a slurry stream comprising solid purified aromatic carboxylic acid and a vapor stream. At least a portion of the vapor stream is directed to the pre-heating zone and at least a portion of the vapor stream from the pre-heating zone is vented to the off-gas treatment zone in order to achieve energy savings.

Provided herein are compounds useful for the preparation of compounds that have retinoid-like biological activity. Also provided herein are processes for the preparation of compounds that have retinoid-like biological activity.

Provided herein are compounds useful for the preparation of compounds that have retinoid-like biological activity. Also provided herein are processes for the preparation of compounds that have retinoid-like biological activity.

Impure aromatic carboxylic acids such as are obtained by liquid phase oxidation of feed materials comprising aromatic compounds with substituent groups oxidizable to carboxylic acid groups, or comprising aromatic carboxylic acid and one or more aromatic carbonyl impurities that form hydrogenated species more soluble in aqueous solvents or with less color or color-forming tendencies than the aromatic carbonyl impurity, are purified to an aromatic carboxylic acid product with lower levels of impurities by a process comprising contacting an aqueous solution comprising the impure aromatic carboxylic acid with hydrogen at elevated temperature and pressure with an attrition-resistance, acid stable catalyst composition comprising at least one hydrogenation catalyst metal and a support comprising relatively high surface area of high porosity silicon carbide with low levels of iron and alkali metal impurities. The support may further contain titanium or rare earth metals.

Impure aromatic carboxylic acids such as are obtained by liquid phase oxidation of feed materials comprising aromatic compounds with substituent groups oxidizable to carboxylic acid groups, or comprising aromatic carboxylic acid and one or more aromatic carbonyl impurities that form hydrogenated species more soluble in aqueous solvents or with less color or color-forming tendencies than the aromatic carbonyl impurity, are purified to an aromatic carboxylic acid product with lower levels of impurities by a process comprising contacting an aqueous solution comprising the impure aromatic carboxylic acid with hydrogen at elevated temperature and pressure with an attrition-resistance, acid stable catalyst composition comprising at least one hydrogenation catalyst metal and a support comprising relatively high surface area of high porosity silicon carbide with low levels of iron and alkali metal impurities. The support may further contain titanium or rare earth metals.

A process for the preparation of a compound having the following formula (I):

##STR00001## wherein R is selected from the group consisting of: halogen, (C.sub.1-C.sub.6)alkoxy, (C.sub.1-C.sub.6)alkyl, halo(C.sub.1-C.sub.6)alkyl, and halo(C.sub.1-C.sub.6)alkoxy, said process including a step of intramolecular cyclisation, a step of bromination, a step of aromatization and a step of oxidation.

A process for the preparation of a compound having the following formula (I):

##STR00001## wherein R is selected from the group consisting of: halogen, (C.sub.1-C.sub.6)alkoxy, (C.sub.1-C.sub.6)alkyl, halo(C.sub.1-C.sub.6)alkyl, and halo(C.sub.1-C.sub.6)alkoxy, said process including a step of intramolecular cyclisation, a step of bromination, a step of aromatization and a step of oxidation.

Processes for manufacturing a purified aromatic carboxylic acid include oxidizing a substituted aromatic compound in a reaction zone to form a crude aromatic carboxylic acid and a gaseous stream; heating the crude aromatic carboxylic acid in a pre-heating zone, contacting the crude aromatic carboxylic acid with hydrogen in the presence of a catalyst in a hydrogenation reactor to form a purified aromatic carboxylic acid, crystallizing the purified aromatic carboxylic acid in a crystallization zone to form a slurry stream comprising solid purified aromatic carboxylic acid and a vapor stream. At least a portion of the vapor stream is directed to the pre-heating zone and at least a portion of the vapor stream from the pre-heating zone is vented to the off-gas treatment zone in order to achieve energy savings.