57628-09-8

Basic information

• Product Name: (RS)-((2RS)-4t-methoxycarbonyl-5,5-dimethyl-thiazolidin-2r-yl)-(2-phenyl-acetylamino)-acetic acid methyl ester
• CAS NO: 57628-09-8
• Molecular Weight: 380.465
• Mol File: 57628-09-8.mol
• Article Data: 1

Chemical Properties

• CAS DataBase Reference: (RS)-((2RS)-4t-methoxycarbonyl-5,5-dimethyl-thiazolidin-2r-yl)-(2-phenyl-acetylamino)-acetic acid methyl ester(CAS DataBase Reference)
• NIST Chemistry Reference: (RS)-((2RS)-4t-methoxycarbonyl-5,5-dimethyl-thiazolidin-2r-yl)-(2-phenyl-acetylamino)-acetic acid methyl ester(57628-09-8)
• EPA Substance Registry System: (RS)-((2RS)-4t-methoxycarbonyl-5,5-dimethyl-thiazolidin-2r-yl)-(2-phenyl-acetylamino)-acetic acid methyl ester(57628-09-8)

Safety Data

• Hazardous Substances Data: 57628-09-8(Hazardous Substances Data)

Upstream product

• 186581-53-3 diazomethane 
• 653-89-4 penicillin G methyl ester 
• 94073-98-0 (RS)-amino-((2RS)-4c-methoxycarbonyl-5,5-dimethyl-thiazolidin-2r-yl)-acetic acid methyl ester; hydrochloride 
• 103-80-0 phenylacetyl chloride 
• 94073-98-0 (RS)-amino-((2RS)-4t-methoxycarbonyl-5,5-dimethyl-thiazolidin-2r-yl)-acetic acid methyl ester; hydrochloride 
• 59054-21-6 (3S,5S,6R)-dimethyl benzylpenicilloate 

Downstream Products

• 59054-21-6 (3S,5S,6R)-dimethyl benzylpenicilloate 

Relevant articles and documents

Thiazolidine Ring Opening in Penicillin Derivatives. Part 1. Imine Formation

The rate of epimerisation of (3S,5R,6R)-benzylpenicilloic acid at C-5 shows three distinct dependencies upon pH in aqueous solution.Below pH 6 the rate shows a sigmoidal dependence upon pH, whereas it is pH-independent between pH 6 and 12, and above pH 12 the rate is hydroxide-ion dependent.These different regions of pH dependence are interpreted in terms of three mechanistic pathways all of which involve opening the thiazolidine ring by C-S bond fission and re-closure to generate the epimer.At low pH the reaction occurs by unimolecular ring opening of the S-conjugate acid which is kinetically equivalent to the N-conjugate acid of pKa 5.14.The pH-independent pathway involves formation of a zwitterion by unimolecular opening of the neutral thiazolidine.At high pH the unprotonated imine intermediate is formed by concerted hydroxide-ion-catalysed ring opening.The mono- and di-methyl esters of benzylpenicilloate also epimerise at C-5.At low pH the rates are similar for all three compounds but above pH 6 the mono- and di-esters are, respectively, 21 and 1700 times less reactive than the dianion of the diacid.