1H-IMIDAZO(4,5-B)PYRAZIN-2-ONES AND PROCESSES FOR THEIR PREPARATION

摘要

1,219,255. 1H - imidazo[4,5-b]pyrazin- 2- ones. MERCK & CO. Inc. 8 April, 1969 [12 April, 1968], No. 17825/69. Heading C2C. The invention comprises compounds of formula wherein RSP1/SP is H, C 2-6 alkylcarbonyl, C 3-7 cycloalkyl, C 3-5 alkenyl, (C 1-3 alkoxy)carbonyl, C 1-5 alkyl, C 1-5 hydroxyalkyl, (C 1-3 alkoxy)-C 1-3 - alkyl, RCH 2 (R = morpholino, piperazino, piperidino, amino, C 1-5 alkylamino, or di-C 1-5 - alkyl-amino), 1-(C 1-3 -alkoxy)carbonyl-C 1-5 -alkyl or 1-(RSP111/SP) 2 NNHCO-C 1-5 -alkyl (RSP111/SP = H or C 1-3 alkyl); RSP2/SP is as defined for RSP1/SP except C 3-5 alkenyl, C 1-5 hydroxyalkyl, (C 1-3 alkoxy)-C 1-3 - alkyl, NH 2 CH 2 or (C 1-5 alkyl)NHCH 2 ; RSP3/SP is H, C 1-5 alkyl, C 3-5 alkenyl, C 3-8 cycloalkyl, C 1-5 hydroxyalkyl, (C 1-3 alkoxy)-C 1-5 alkyl, phenyl- C 1-5 alkyl, (C 1-5 alkoxy)carbonyl-C 1-5 -alkyl, (mononuclear aroyl)-C 1-5 -alkyl, cyano-C 1-5 -alkyl or heterocyclic-substituted C 1-5 alkyl (the heterocyclic ring containing 5 or 6 members including 1 or 2 N atoms); X is H or halogen, and Y is O or S. These compounds may be prepared by (a) reacting an appropriately substituted 3-aminopyrazinoic acid hydrazide with HNO 2 and heating the 3-aminopyrazinoic acid azide so formed; (b) effecting substitution of the compounds of the above formula wherein RSP1/SP and/or RSP2/SP is hydrogen; (c) reacting the above compounds where RSP1/SP and/or RSP2/SP is 1-(C 1-3 - alkoxy)carbonyl-C 1-5 -alkyl, with N 2 H 4 . The hydrazides for method (a) are prepared from esters of substituted 3-aminopyrazinoic acids. Therapeutic compositions, for administration orally or by injection, comprise compounds of the above formula which are antihypertensive agents with some diuretic and saluretic activity.