Uracil 5-bromo-1,3-dimethyl

A more promising method is the cyclization of a prop-2-ynamino group in the 5-position. Thus, treatment of l,3-dimethyl-5-(prop-2-ynamino)uracil, prepared from 5-bromo-l,3-dimethyluracil and prop-2-ynamine, with palladium(II) acetate affords a 40% yield of 1,3-dimethylpyrido[3,2-t/]pyrimidine-2,4(l//,3//)-dione (6).212... 

---