N,N-Dimethylaniline → 6-Aminopenicillanic acid

Participants

Reaction Steps

To a suspension of 14.9 g of penicillin-G-potassium in 60 ml of absolute methylene chloride, 5.06 g (=40 mmols) of methylethylphosphinic acid chloride and 10 ml of dimethylaniline were added in the same manner as indicated in Example 1. The mixture was stirred for 1 hour and the solution of the mixed anhydride so prepared was converted at -5°C with 9.0 g (= 43 mmols) of phosphorus of pentachloride into the imidochloride. After addition of 60 ml of n-butanol and 2 ml of N,N-dimethylaniline, the mixture was stirred at -5°C for 30 minutes. 60 ml of ice water were added and the 6-aminopenicillanic acid was separated at pH 4. 6.47 g (= 76.4 % of the theory) of 6-aminopenicillanic acid were isolated in the form of colorless crystals having a melting point of 195°C (decomposition) which are identical with authentic 6-aminopenicillanic acid according to the IR-spectrum and the mixed melting point.

Provenance & Evidence