Council of Scientific and Industrial Research

Celanese International Corporation

Milind Yashwant Gupte

Prashant Purushottam Barve

Ravindra William Shinde

Chandrashekhar Narayan Joshi

Shrikant Madhukar Ghike

Melchior A Meilchen

Ilias S Kotsianis

Sanjay Narayan Nene

Barbara F M Kimmich

Sanjay Pandurang Kamble

Hang Wang

Bhaskar Datttraya Kulkarni

Gopal Moreshwar Chaphekar

Sunil Shankar Joshi

Satish N Shintre

Raghavendra Venkatrao Naik

Bhaskar Dattatraya Kulkarni

Vilas Bhiku Chavan

Gandhali Arun Thite

Rajendra Anantrao Kulkarni

Aruna Narayan Bote

Tushar Ramchandra Deshpande

Bhaskar Dattatreya Kulkarni

Ravindra William c/o Anil D Kulkami Irp Co-Ordinator Shinde

A continuous process is provided for selective formation of a vinyl ester by reactive distillation from a corresponding carboxylic acid. Carboxylic acid, vinyl acetate, and a palladium acetate&#x2014;bidentate ligand catalyst complex are provided and reacted in a typical embodiment. Acetic acid and vinyl acetate are continuously removed from the reaction mixture and vinyl acetate is recycled to the reaction mixture. The vinyl ester product is separated from the vinyl acetate, residual carboxylic acid, residual acetic acid, and catalyst.

Process for the continuous transvinylation of carboxylic acids with vinyl acetate

A semi-continuous process is provided for selective formation of a vinyl ester by reactive distillation from a corresponding carboxylic acid. Carboxylic acid, vinyl acetate, and a palladium acetate&#x2014;bidentate ligand catalyst complex are provided and reacted in a typical embodiment. Acetic acid and vinyl acetate are continuously removed from the reaction mixture and vinyl acetate is recycled to the reaction mixture. The vinyl ester product is separated from the vinyl acetate, residual carboxylic acid, residual acetic acid, and catalyst.

Process for the semi-continuous transvinylation of carboxylic acids with vinyl acetate

The dehydrated alkali metal salts of carboxylic acid are dissolved in the alcohol such as methanol or ethanol or butanol to make their solution in corresponding alcohol. The solution alcohol is further treated with carbon dioxide under pressure or at atmospheric pressure at elevated temperature such as 150 to 200&#xb0; C. The carboxylic acid gets converted into corresponding alkyl ester and calcium carbonate or sodium carbonate or potassium carbonate as the byproduct. Calcium lactate or sodium lactate or sodium acetate or sodium benzoate or sodium salicylate as alkali metal salt solution prepared in methanol or ethanol or butanol when treated with carbon dioxide under pressure or at atmospheric pressure at elevated temperature gets converted to methyl lactate or ethyl lactate or methyl acetate or methyl benzoate or methyl salicylate as product.

Process for preparation of pure alkyl esters from alkali metal salt of carboxylic acid

The present invention provides a commercially viable process for the preparation of highly pure and optically active L-(+)-lactic acid and S-(&#x2212;)-methyl lactate, in high yield, obtained from esterification of aqueous crude lactic acid solution produced by sugar cane juice fermentation broth and methanol in continuous counter current trickle phase approach or in continuous counter current bubble column manner, using stabilizers and the methyl lactate so obtained is recovered and followed by purification of reasonably pure methyl lactate using reagent mixture such as sodium bi-carbonate, mono-ethanolamine or di-ethanolamine, urea or sodium-bicarbonate, mono-ethanolamine or di-ethanolamine, thiourea to reduce the impurity of dimethyl ester of dicarboxylic such as dimethyl oxalate or di-methyl succinate or methyl ester of mono-carboxylic acid such as methyl pyruvate present as an impurity, so as to get highly pure S-(&#x2212;)-methyl lactate followed by hydrolyzing highly pure S-(&#x2212;)-methyl lactate using highly pure lactic acid as a catalyst, using highly pure water as the hydrolysis media and by using pre-treated activated carbon with dilute L-(+)-lactic acid, in batch or continuous mode. This very high pure S-(&#x2212;)-methyl lactate constitutes an important product having interesting possibilities of application at an industrial level, in pharmaceuticals. Highly pure L-(+)-lactic acid thus obtained is used as an acidulant, as a food additive, for pharmaceutical applications, a monomer for making poly-lactic acid, as a monomer to prepare biodegradable polymer which are useful for manufacturing bags, application films, in the field of sanitary field, and has medical applications.

Process for preparing L- (+) -lactic acid

Process for recovery of highly pure acrylonitrile by quickly vaporizing under vacuum the contaminated acrylonitrile as well as fresh acrylonitrile followed by contacting with hydrophilic agents in an extractive distillation column using plural number of packed sections.

Process for recovery of pure acrylonitrile

The present invention provides a process for the preparation of highly pure 2-Methyl-2-propene-1-sulfonic acid, sodium salt in high yield, with very low iron content, by the reaction of distilled sulfur trioxide complexed with a Lewis base in a halogentated solvent, the unreacted sulfur trioxide vapors being removed from the reactor before the mixture is treated with liquefied isobutylene, and neutralization by a base with an iron content within the range of 0 to 20 ppm.

Process for the preparation of 2-Methyl-2-propene-1-sulfonic acid, sodium salt

The present invention provides a process for the preparation of highly pure 2-acrylamido-2-methyl-1-propanesulfonic acid in high yield, with improved appearance, by the reaction of acrylonitrile with more than 98% sulfuric acid or oleum and liquefied isobutylene in presence of weak inorganic acids or organic sulfonic acids.

Process for the preparation of 2-acrylamido-2-methyl-1-propanesulfonic acid

Growing community of inventors

Maharashtra, India

Milind Yashwant Gupte