Preparation of 2-Amino-4(3H)-oxopyrimidothiazines (5-Thiapterins) and Their Evaluation as Cofactors for Phenylalanine Hydroxylase

Article abstract of DOI:10.1021/jm00358a019

Reaction of diethyl chloromalonate with β-mercapto amines, 9, gave 1,4-thiazin-3-ones, 10, which were alkylated exclusively at the lactam oxygen with triethyloxonium tetrafluoroborate and subsequently condensed with guanidine to give the first reported 5-