62987-29-5

Upstream product

• 60761-30-0 (6R)-3-methylene-8-oxo-7t-(2-phenoxy-acetylamino)-(6rH)-5-thia-1-aza-bicyclo[4.2.0]octane-2c-carboxylic acid 4-nitro-benzyl ester 
• 80927-87-3 (6R,7R)-3-Carbamoyloxymethyl-8-oxo-7-(2-phenoxy-acetylamino)-5-thia-1-aza-bicyclo[4.2.0]oct-2-ene-2-carboxylic acid 4-nitro-benzyl ester 
• 61375-82-4 (6R)-3-methylene-5ξ,8-dioxo-7t-(2-phenoxy-acetylamino)-(6rH)-5λ⁴-thia-1-aza-bicyclo[4.2.0]octane-2c-carboxylic acid 4-nitro-benzyl ester 
• 62987-30-8 (6R)-3-acetoxymethyl-8-oxo-7t-(2-phenoxy-acetylamino)-(6rH)-5-thia-1-aza-bicyclo[4.2.0]oct-2-ene-2-carboxylic acid 4-nitro-benzyl ester 

Relevant academic research and scientific papers

Process for preparation of 3-halomethylcephems

3-Halomethyl-3-cephems are provided by reacting a 3-methylenecepham with an alkali metal salt of a lower alcohol or a bicyclic amidine base in the presence of a positive halogenating agent at a temperature ranging from -80° to about 20° C. The 3-halomethylcephems provided by this invention are useful intermediates for the preparation of known cephalosporin antibiotics.