MANUFACTURE OF 22SUBSTITUTEDD66ALKOXYCARBONYLL 88ETHYLL55OXOO5*88DIHYDROOPYRIDOO*2*33D** PYRIMIDINES AND CORRESPONDING FREE ACIDS

摘要

The invention relates to a process for the preparation of 2-substituted 6-alkoxycarbonyl-8-ethyl- 5-oxo-5, 8-dihydro-pyrido-[2, 3,-d]-pyrimidines and corresponding free acids, having the following general formula: CHEM wherein R1 = H, CH3, C2H5, and R2 = Cl, CH3O, C2H5O, CH3S, CH3SO2 which are useful intermediates for the preparation of bacteriostatic agents, such as pyromidic and pipemidic acid. The process, in the essential part, is characterized by an oxidation of the corresponding tetrahydroderivative.