7-Aminocephalosporanic acid → 7-Amino-3-(1-carbamoylmethyl-1H-tetrazol-5-ylthio)methylceph-3-em-4-carboxylic acid

Participants

Reaction Steps

7-Aminocephalosporanic acid (5.44 g., 20 mmole) and 5-Mercapto-1H-tetrazol-1-ylacetamide (3.50 g., 2.2 mmole) were suspended in 50% aqueous acetone (200 ml) and solid sodium bicarbonate added until a clear solution was obtained, ~pH 7.0. The solution was heated at 60° for 6 hours, uncovered for the final hour which allowed most of the acetone to evaporate, then acidified to pH 4.0 and stirred in an ice bath for one hour. The solid product was collected, washed with a little cold water and dried in vacuo, 3.22 g (43.4%), δ(CF3CO2H) 4.00 (2H,bs, C2 methylene), 4.69 (2H,bs, --CH2S--), 5.56 (4H,s, --CH2CO2NH2 and β-lactam protons), 7.4-7.8 (2H,m, --CONH2).

Provenance & Evidence