Pyridine → HCID 131713654, compound

Participants

Reaction Steps

In the manner described in Example 12, 3.63 g of 3-acetoxymethyl-7β-[(2S)-2-(4-aminophenyl)-2-(4-ethyl-2,3-dioxopiperazine-1-carboxamido)-acetamido]-3-cephem-4-carboxylic acid diphenylmethyl ester p-toluenesulphonate are reacted with 3.03 g of (2R)-2-BOC-amino-2-diphenylmethoxycarbonylethoxycarbonyl chloride and 0.76 ml of pyridine in 100 ml of tetrahydrofuran and worked up. The crude product is chromatographed over 400 g of silica gel (500 ml fractions), fractions 1-12 being eluted with toluene/ethyl acetate (1:1), fractions 13-19 with toluene/ethyl acetate (2:3) and the later fractions with ethyl acetate. By reprecipitating fractions 14-25 from CH2Cl2 /ether/hexane, 3-acetoxymethyl-7β-{(2S)-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 =19°±1° (0.96% in CHCl3), IR: 3570, 3400, 1795, 1750-1700 (wide), 1620, 1608, 1510 cm-1 (CH2Cl2).

Provenance & Evidence