Annelation of 5 or 6 membered heterocycles to uracil derivatives via phosgeniminium salt(1) condensation

Abstract
PI salts condense with 1, 3‐dimethyl barbituric acid and 1, 3‐dimethyl‐4 ‐amino uracil to give new amide chlorides 4 and 5. These synthons lead to new aminated isoxazolo‐, or pyrimido‐ and pyrido‐pyrimidines 12, 16 & 18 on cyclisation with hydroxylamine, cyanamide and malononitrile, respectively.