Asymmetric chemoenzymatic synthesis of N-acetyl-α-amino esters based on lipase-catalyzed kinetic resolutions through interesterification reactions

Add time:08/16/2019    Source:sciencedirect.com

Several phenylalanine analogs have been synthesized through a four-step route starting from easily available ethyl acetamidocyanoacetate. In a first reaction, and making use of phase transfer catalysts, this compound reacted with several alkyl halides, being benzyltributylammonium chloride identified as the best one for the production of a series of quaternary amino acids in moderate to excellent yields (52–95%). Then, the corresponding N-acetyl-phenylalanine methyl and allyl ester derivatives were obtained through acidic hydrolysis, esterification, and N-acetylation. Rhizomucor miehei lipase was found as a versatile enzyme for the resolution of these amino esters, finding the best results through interesterification reactions with butyl butyrate in acetonitrile. A great influence in the stereoselectivity was found depending on the chemical structure of the compound, achieving for the non- or para-substituted in the phenyl ring excellent stereoselectivities, being moderate for the meta-nitro derivative, while the ortho-nitro amino ester did not react.

We also recommend Trading Suppliers and Manufacturers of 2-(2-CHLORO-ACETYLAMINO)-4-P-TOLYL-THIOPHENE-3-CARBOXYLIC ACID ETHYL ESTER (cas 138098-81-4). Pls Click Website Link as below: cas 138098-81-4 suppliers

Prev:Synthesis and in vivo evaluation of [18F]-N-(p-Nitrobenzyl)spiperone ([18F]PNBS) in rats
Next:Evaluation of glycolamide esters of indomethacin as potential cyclooxygenase-2 (COX-2) inhibitors☆)