Abstract
The behaviours of 7-amino-2, 3-dimethyl- and 7-amino-2, 3, 6-trimethylpyrazolo [1, 5-α]-pyrimidines (I, II) against acylation and alkylation were investigated. Mono- and diacylates were obtained from II but only monoacylate from I, of which reason was considered due to the steric effect of the methyl group at the 6-position. The substitution position of acyl groups was confirmed to be at 7-amino group but alkyl groups at N-4 position, respectively, from their chemical and physical evidences. Their nuclear magnetic resonance and ultraviolet spectra were also discussed briefly.
