抄録
The present work was undertaken in order to synthesize oxazolo[4, 5-d]pyrimidines which are of interest as antimetabolites. The Schotten-Baumann reaction of 2, 4-diamino-5-hydroxy-6-methylpyrimidine (III) with ethyl chlorocarbonate gave 2, 4-diamino-5-ethoxycarbonyloxy-6-methylpyrimidine (XII). XII was refluxed in pyridine to give 5-amino-7-methyloxazolo[4, 5-d]pyrimidin-2(3H)-one (XIII), which was alkylated with alkyl halide to give 3-alkyloxazolo[4, 5-d]pyrimidine derivatives (XIVa-d). Also the Schotten-Baumann reaction of III with ethyl bromoacetate and ethyl α-bromopropionate gave pyrimido[5, 4-b][1, 4]oxazine derivatives (XV) and (XVII), respectively.
