Pyridine → HCID 131713653, compound

Participants

Reaction Steps

In the manner described in Example 12, 4.56 g of 3-acetoxymethyl-7β-[(2R)-2-(4-aminophenyl)-2-(4-ethyl-2,3-dioxopiperazine-1-carboxamido)-acetamido]-3-cephem-4-carboxylic acid diphenylmethyl ester p-toluenesulphonate are reacted with 3.8 g of (2R)-2-BOC-amino-2-diphenylmethoxycarbonylethoxycarbonyl chloride and 0.95 ml of pyridine in 135 ml of tetrahydrofuran and worked up. Th resulting crude product is chromatographed over 400 g of silica gel (500 ml fractions), fractions 1-12 being eluted with toluene/ethyl acetate (3:2) and the later fractions with toluene/ethyl acetate (1:1). By reprecipitating fractions 9-23 from CH2Cl2 /ether/hexane, 3-acetoxymethyl-7β-{(2R)-2-[4-((2R)-2-BOC-amino-2-diphenylmethoxycarbonylethoxycarbonylamino)-phenyl]-2-(4-ethyl-2,3-dioxopiperazine-1-carboxamido)-acetamido}-3-cephem-4-carboxylic acid diphenylmethyl ester is obtained. [α]D20 =+8°±1° (0.82% in CHCl3).

Provenance & Evidence