ペニシリンの研究 (第7報)

Penicillamine合成の追加研究

抄録

1) Corresponding betaine hydrochloride was prepared from N-chloroacetylvaline and pyridine. Treatment of the former with excess of pyridine and acetic anhydride or of β-hydroxyvaline with acetic anhydride gives 2-methyl-4-isopropylidene-5-oxazolone.
2) By the hydrolysis of methyl α-acetylamino-β-benzylmercapto-β, β-dimethylpropionate to the corresponding acid, debenzylation of this with liquid ammonia and metallic sodium, and finally isolation of N-acetyl radical, penicillamine was obtained in good yield.
3) Addition of HS to 2-phenyl-4-isopropylidene-5-oxazolone gave N-benzoyl-penicillamine. This compound is easily benzylated to give S-benzyl-N-benzoyl-penicillamine.