Synthesis of chrysogine, a metabolite of Penicillium chrysogenum and some related 2-substituted 4-(3H)-quinazolinones

Article abstract of DOI:10.1016/S0040-4020(01)86694-1

Syntheses of both enantiomers of chrysogine, 2-(α-hydroxyethyl)-4(3H)-quinazolinone, 1 from 2-ammobenzamide are reported. Thus reaction of 2-aminobenzamide and optically active α-acetoxypropionyl chloride gave 9, which upon saponification and cyclization induced by aqueous sodium carbonate at room temperature gave chrysogine. The enantiomeric purity of 1 was determined by NMR. Inversion of (-)-(S)-1, using the Mitsunobo reaction, gave (+)-(R)-1. Reduction of 2-acetyl-4(3H)-qumazolinone 2 with baker's yeast gave the S-enantiomer of 1. The cyclization method used could be extended and a number of 2-(a-hydroxy)alkyl-4-(3H)-quinazolinones are also reported.