METHOD OF OBTAINING 1-3-(6,7-DIHYDRO-1-METHYL-7-OXO-3-PROPYL-1H-PYRAZOLE4,3-DPYRIMIDYN-5-YL)-4-ETHOXYPHENYLSULPHONYL-4-METHYLOPIPERAZINE AND 1-ETHYL-4-3-3-ETHYL-6,7-DIHYDRO-7-OXO-2-(2-PYRIDILOMETHYL)-2H-PYRAZOLE4,3-DPYRIMIDIN-5-YL-4-PROPOXYPHENYLSULPHONYLPIPERAZINE, NOVEL PYRAZOLOCARBOXAMIDES, NOVEL (1H-PYRAZOLE-4,3-DPYRIMIDINYLPHENYSULPHONYL)PIPERAZINES AND NOVEL PIPERAZINYLSULPHONYLBANZOIC ACIDS

摘要

A process is provided for the preparation of a compound of formulae (IA) (sidenafil/ ViagraTm TM ) and (IB) CHEM comprising reacting a compound of formula (IIA) and (IIB) respectively in the presence of -OR, wherein R in the case of formation of compound (IA) is CH2CH3 and R in the case of formation of compound (IB) is CH2CH2CH3, where X is a leaving group: CHEM