Patent GB-1447672-A (GB)
Title: Amino derivatives of pyrazolopyridine carboxamides
IPC: A61P25/20
Filed: 1973-11-02
Abstract: 1447672 Pyrazolo[3,4-b]pyridine derivatives E R SQUIBB & SONS Inc 2 Nov 1973 [15 Nov 1972] 50984/73 Heading C2C Novel pyrazolo[3,4-b]pyridine derivatives of the formula wherein R 1  is H, C 1-8  alkyl, phenyl, phenyl- C 1-8  alkyl or C 3-7  cycloalkyl; R 2  is H, C 1-8  alkyl or phenyl; R 3  and R 4  each are H, C 1-8  alkyl, C 2-8  alkenyl, C 2-8  alkanoyl, optionally substituted phenyl, phenyl-C 1-8  alkyl, di(C 1-8  alkyl)amino-C 1-8  alkyl, optionally substituted benzoyl, phenyl-C 2-8  alkanoyl, alkanesulphonyl, or optionally substituted benzene-sulphonyl, or R 3  and R 4  together with the nitrogen atom to which they are attached form 3- to 6- membered heterocyclic ring optionally containing a further hetero atom; R 5  and R 6  are each H, C 1-8  alkyl mono- or di-(C 1-8  alkoxy)-C 1-8  alkyl or di-(C 1-8  alkyl)amino-C 1-8  alkyl, or R 5  and R 6  together with the nitrogen atom to which they are attached form a 5- to 7-membered heterocyclic ring optionally containing a further heteroatom; R 7  is H, C 1-8  alkyl or phenyl; and physiologically acceptable acid addition salts thereof are prepared by reacting compounds of the Formula II wherein X and Y are each halogen or alkoxy, with amines of the formulµ The following intermediates are also prepared: {[(1 - ethyl - s - pyrazolyl)amino]methylene}- malonic acid diethyl ester, 1-ethyl-1,7-dihydro- 4 - oxo - 4H - pyrazolo[4,3 -b]pyridine - s - carboxylic acid, its ethyl ester and the acid chloride thereof, 1 - ethyl - 1,7 - dihydro - 3 - methyl- 4 - oxo - 4H - pyrazolo[4,3 - b]pyridine - 8 - carboxylic acid and its ethyl ester, {[(1-ethyl-3- methyl - 5 - pyrazolyl)amino]methylene}- malonic acid diethyl ester, 4-chloro-1-ethyl- 3 - methyl - 1H- pyrazolo[3,4 - b]pyridine- 5-carboxylic acid chloride, 4-chloro-1-ethyl-N- (2,2-diethoxyethyl) - 3 - methyl - 1H - pyrazolo- [3,4 - b]pyridine - 5 - carboxamide, 4 - chloro- 1 - ethyl - 1H - pyrazolo[3,4 - b]pyridine - 5 carboxylic acid ethyl ester, 4-butylamino-1- ethyl - 1H - pyrazolo[3,4 - b]pyridine - 5 - carboxylic acid, its ethyl ester and acid chloride thereof {[(1 - (2 - furyl)methyl - 5 - pyrazolyl)- amino]methylene} - malonic acid diethyl ester, 1 - (2 - furyl)methyl - 1,7 - dihydro - 4 - oxo- 4H - pyrazolo[4,3 - b]pyridine - 5 - carboxylic acid ethyl ester, 4-ethoxy-1-(2-furyl)-methyl- 1H - pyrazole[3,4 - b]pyridine - 5 - carboxylic acid ethyl ester, 4 - ethoxy - 1H - pyrazolo- [3,4 - b] - pyridine - 5 - carboxylic acid ethyl ester, 4 - butylamino - 1H - pyrazolo[3,4 - b]- pyridine - 5 - carboxylic acid, its ethyl ester and the acid chloride thereof, {[( 1 - (4 - pyridyl)- methyl - 5 - pyrazolyl)amino] - methylene}- malonic acid diethyl ester, 1,7 - dihydro - 4, oxo - 1 - (4 - pyridyl)methyl - 4H - pyrazolo- [3,4 b]pyridine - 5 - carboxylic acid ethyl ester, 1,7 - dihydro - 4 - oxo - 4H - pyrazolo- [3,4 - b]pyridine - 5 - carboxylic acid ethyl ester, 4 - ethoxy - 1H - pyrazolo[3,4 - b]pyridine- 5 - carboxylic acid ethyl ester, and 4 - bylamino - 1H - pyrazolo[3,4 - b]pyridine - 5 - carboxylic acid, its ethyl ester and the acid chloride thereof. Pharmaceutical compositions, suitable for oral or parenteral administration, contain the above novel compounds or physiologically acceptable acid addition salts thereof and pharmaceutical carriers. The compounds possess central nervous system depressant, analgesic and hypotensive activities.