Pyrazolopyridazine antihypertensives

A compound in accordance with claim 1, 2,3,5,8-Tetrahydro-2-(2-mercaptoethyl)-2-methyl-1,3-dioxo-1H-pyrazolo[1,2- a]pyridazine-5-carboxylic acid.

A compound of the formula ##STR19## wherein R.sup.3 is hydrogen, lower alkyl, aryl or aryl-(lower alkyl)-, R.sup.20 lower alkoxy and R.sup.40 is hydrogen, lower alkyl, aryl or aryl-(lower alkyl)-.

A compound of the formula ##STR20## wherein A is methylene, ethylene or propylene which may be substituted by lower alkyl, B is carbonyl or methylene, R.sup.2 hydroxy, lower alkoxy or amino, R.sup.3 is hydrogen, lower alkyl, aryl or aryl-(lower alkyl)-, R.sup.5 is hydroxy, R.sup.41 is hydrogen, lower alkyl, aryl or aryl-(lower alkyl)- or a group of the formula -A-R.sup.5 in which A and R.sup.5 are as described above and the broken line denotes an optional carbon-carbon bond which can be present only when B is carbonyl.

A method of controlling or preventing hypertension which comprises administering to a host requiring such treatment a pharmaceutical composition containing an effective amount of a compound of the formula ##STR21## wherein A is methylene, ethylene or propylene which may be substituted by lower alkyl, B is carbonyl or methylene, R.sup.1 is halogen, carboxyl, lower alkoxycarbonyl, hydroxyaminocarbonyl, mercapto, lower alkanoylthio or aryl-(lower alkylthio)-, R.sup.2 is hydroxy, lower alkoxy or amino, R.sup.3 is hydrogen, lower alkyl, aryl or aryl-(lower alkyl)-, R.sup.4 is hydrogen, lower alkyl, aryl or aryl-(lower alkyl)- or a group of the formula -A-R.sup.1 wherein A and R.sup.1 are as described above and the broken line denotes an optional carbon-carbon bond which can be present only when B is carbonyl, or a salt of a compound of formula 1, wherein R.sup.1 is carboxy and/or R.sup.2 is hydroxy, with a pharmaceutically acceptable base.

A compound of the formula ##STR22## wherein A is methylene, ethylene or propylene which may be substituted by lower alkyl, B is carbonyl or methylene, R.sup.2 is hydroxy, lower alkoxy or amino, R.sup.3 is hydrogen, lower alkyl, aryl or aryl-(lower alkyl)-, R.sup.6 is lower alkylsulfonyloxy or arylsulfonyloxy, R.sup.43 is hydrogen, lower alkyl, aryl or aryl-(lower alkyl)- or a group of the formula -A-R.sup.6 in which A and R.sup.6 are as described above and the broken line denotes an optional carbon-carbon bond which can be present only when B is carbonyl.

A compound of the formula ##STR23## wherein A is methylene, ethylene or propylene which may be substituted by lower alkyl, B is carbonyl or methylene, R.sup.2 is hydroxy, lower alkoxy or amino, R.sup.3 is hydrogen, lower alkyl, aryl or aryl-(lower alkyl)-, R.sup.8 is aryloxycarbonyl, R.sup.44 is hydrogen, lower alkyl, aryl or aryl-(lower alkyl)- or group of the formula -A-R.sup.8 in which A and R.sup.8 are as described above and the broken line denotes an optional carbon-carbon bond which can be present only when B is carbonyl.

A compound of the formula ##STR24## wherein A is methylene, ethylene or propylene which may be substituted by lower alkyl, R.sup.20 is lower alkoxy, R.sup.3 is hydrogen, lower alkyl, aryl or aryl-(lower alkyl)-, Z is benzyloxycarbonyl and R.sup.45 is hydrogen, lower alkyl, aryl or aryl-(lower alkyl)- or a group of the formula -A-Z in which A and Z are as described above.

A pharmaceutical composition for controlling or preventing hypertension comprising an effective amount of a compound of the formula ##STR25## wherein A is methylene, ethylene or propylene which may be substituted by lower alkyl, B is carbonyl or methylene, R.sup.1 is halogen, carboxyl, lower alkoxycarbonyl, hydroxyaminocarbonyl, mercapto, lower alkanoylthio or aryl-(lower alkylthio)-R.sup.2 is hydroxy, lower alkoxy or amino, R.sup.3 is hydrogen, lower alkyl, aryl or aryl-(lower alkyl)-, R.sup.4 is hydrogen, lower alkyl, aryl or aryl-(lower alkyl)- or a group of the formula -A-R.sup.1 wherein A and R.sup.1 are as described above and the brokenline denotes an optional carbon-carbon bond which can be present only when B is carbonyl, or a salt of a compound of formula I, wherein R.sup.1 carboxy and/or R.sup.2 hydroxy, with a pharmaceutically acceptable base, and a pharmaceutical carrier material.