SE380023

1,247,081. 4 - Imino - -1,4 - dihydropyridines. MERCK & CO. Inc. 1 July, 1969 [5 July, 1968; 1 May, 1969], No. 33111/69. Heading C2C. Novel compounds of the Formula I in which the hetero substituent has the Formulµ II or III each of R1, R2, R4, R5 and R7 is H or C 1-3 alkyl and each of R3 and R6 is H, C 1-3 alkyl or phenyl, and their acid addition salts, are prepared generally by condensing an appropriate 4- aminopyridine with a 2-X-pyrimidine or 2-X- pyrazine in which X is halogen, sulpho, C 1-3 alkylthio, C 1-3 alkylsulphinyl, C 1-3 alkylsulphonyl, C 1-3 alkoxy, phenoxy, benzyloxy, tri - (C 1-3 alkyl) ammonium salt or nitro. They may also be prepared by (a) generation of the 4-imino substituent attached to the pyridine residue; (b) formation of the pyridine ring, the pyrimidine ring, or both rings; (c) aromatization by oxidation of dihydro up to dodecahydro derivatives; (d) removal of extraneous groups attached to either or both of the heterocyolic rings; (e) ring expansion to form the 1,4-dihydropyridine ring; and (c) interchange of quaternary residues. Intermediates.-The following compounds are prepared in the examples: 2-fluoropyrimidine, 2 - methylsulphonylpyrimidine, 2 - methylsulphinylpyrimidine, 2 - pyrimidinyltrimethylammonium chloride, 2-nitropyrimidine, 1-(2- pyrimidinyl) - 4 - acetylimino - 1,4 - dihydropyrimidine, N - (4 - pyridyl) bromoformamidine, N - methyl - N1 - (4 - pyridyl) guanidine, 4 - pyridylacetamidine, 4 - (bemylideneamino)pyridine, 1 - (2 - pyrimidinyl) - 4 - carbamoyl - pyridinium chloride, 1 - (2 - pyrimidinyl) - 4 - oxo - 1,4 - dihydropyridine, 1 - (2- pyrimidinyl) - 4 - thio - 1,4 - dihydropyridine, 1 - (2 - pyrimidinyl) - 4 - chloropyridinium chloride, 1 - (2 - pyrimidinyl) - 4,4 - dimethoxy- 1,4 - dihydropyridine, 1 - (2 - pyrimidinyl) - 4- mercaptopyridinium chloride, 4 - methylsulphinylpyridine, N - amidino - 1,4 - dihydropyridin - 4 - one, 1 - amidino - 4 - chloropyridinium chloride, N - amidino - 4 - imino - 1,4- dihydropyridine, 3 - ketoglutaraldehyde tetraethylacetal, 3,31 - azino bis - (glutaraldehyde tetraethyl bis - acetal), 2 - chloro - 1,4,5,6 - tetra hydropyrimidine, 1 - [2 - (1,4,5,6 - tetrahydro)- pyrimidinyl] - 4 - imino - 1,4 - dihydropyridine 1 - (2 - pyrimidinyl) - 2,6 - dicarboxy - 4 - imino- 1,4 - dihydropyridine, 1 - (2 - pyrimidinyl) - 4- imino - tetrahydropyridine, 1 - (5 - carboxy - 2- pyrimidinyl) - 4 - imino - 1,4 - dihydropyridine, 3,31 - dithio bis (4 - ethoxycarbonylaminopyridine) 1 - (2 - pyri