75636-71-4

Upstream product

• 17672-53-6 bis-(2,2,2-trichloroethyl)phosphorochloridate 
• 3956-31-8 (2S,6R)-6-Amino-3,3-dimethyl-7-oxo-4-thia-1-aza-bicyclo[3.2.0]heptane-2-carboxylic acid benzyl ester 

Downstream Products

• 62801-95-0 (2S,6S)-6-[Bis-(2,2,2-trichloro-ethoxy)-phosphorylamino]-6-methoxy-3,3-dimethyl-7-oxo-4-thia-1-aza-bicyclo[3.2.0]heptane-2-carboxylic acid benzyl ester 
• 35353-33-4 benzyl 6α-methoxy-6β-(phenylacetamido)penicillanate 

Relevant academic research and scientific papers

A Method for the Preparation of 7α-Methoxycephalosporins

A method for the preparation of 7α-methoxycephalosporins has been developed. 7β-Phosphoramidodeacetoxycephalosporin (6) and 7β-phosphoramidocephalosporin (14) obtained from the 7β-amino-derivatives (5) and (13), were converted into 7α-methoxy-7β-phosphoramidodeacetoxycephalosporin (7) and 7α-methoxy-7β-phosphoramidocephalosporin (15), respectively, by reaction with LiOMe and ButOCl.Treatment of (7) with BunLi and Et3N followed by acylation with phenylacetyl chloride gave 7α-methoxy-7β-phenylketenimino-derivative (11), which were easily hydrated to 7α-methoxy-7β-(phenylacetamido)deacetoxycephalosporin (12).Treatment of (15) under similar conditions afforded, contrary to the result obtained with (7), 7α-methoxy-7β-(phenylacetamido)cephalosporin (16), without any of the corresponding ketenimine.This method was also successfully applied to the synthesis of 6α-methoxypenicillins.