Mechanistic Investigations with the Aid of Isotopic Labeling, VIII. Investigations of the Reaction Pathway to Pyrrolopyrimidines from 4-Benzoyl-5-phenyl-2,3-furandione and Aryl Isocyanates
4-Benzoyl-5-phenyl-2,3-furandione (1) reacts with aryl isocyanates to yield the pyrrolopyrimidines 4 and the 2,3-pyrrolediones 2; using alkyl isocyanates the corresponding 2,3-pyrrolediones 2e - g are formed exclusively.The formation of 4 and 2 inc