Abstract
Formamide and ethyl orthoformate-acetic anhydride mixture (1 : 1) have been compared for their cyclization properties to form various 4, 5-diamino-6-substituted-aminopyrimidines. It has been confirmed that the former yields 9-substituted-purines and the latter, 6-sub-stituted-aminopurines, indicating that the ring closure occurs between 5-and 6-amino groups in the former and between 4-and 5-amino groups in the latter. Identification of the reaction products was made through their ultraviolet spectral data.
