Indazolyl carboxylic acid amides useful for treating migraine clusters headache, trigeminal neuralgia or emesis

A compound of formula (I), or a pharmaceutically acceptable salt thereof:

• ##STR22## wherein X is CO and Y is NH;
• Z is NR.sub.3 wherein R.sub.3 is hydrogen, C.sub.1-6 alkyl, C.sub.3-7 alkenyl-methyl, phenyl or phenyl C.sub.1-4 alkyl either of which phenyl moieties may be substituted by one or two of halogen, CF.sub.3, C.sub.1-6 alkoxy or C.sub.1-6 alkyl;
• R.sub.b is present when X-Y-R.sub.2 is attached at the phenyl ring and is selected from hydrogen, halogen, CF.sub.3, hydroxy, C.sub.1-6 alkoxy or C.sub.1-6 alkyl;
• R.sub.1 is hydrogen, halogen, CF.sub.3, C.sub.1-6 alkyl, C.sub.1-6 alkoxy, C.sub.1-6 alkylthio, C.sub.1-7 acyl, C.sub.1-7 acylamino, C.sub.1-6 alkylsulphonylamino, N-(C.sub.1-6 alkylsulphonyl)-N-C.sub.1-4 alkylamino, C.sub.1-6 alkylsulphinyl, hydroxy, nitro or amino, aminocarbonyl, aminosulphonyl, aminosulphonylamino or N-(aminosulphonyl)-C.sub.1-4 alkylamino optionally N-substituted by one or two groups selected from C.sub.1-6 alkyl, C.sub.3-8 cycloalkyl, C.sub.3-8 cycloalkyl C.sub.1-4 alkyl, phenyl or phenyl C.sub.1-4 alkyl groups or optionally N-disubstituted by C.sub.4-5 polymethylene;
• R.sub.2 is a group of formula (a), ##STR23## wherein n is 2 or 3;
• and R.sub.4 is C.sub.1-7 alkyl, C.sub.3-8 cycloalkyl, C.sub.3-8 cycloalkyl-C.sub.1-2 alkyl, or a group (CH.sub.2).sub.t R.sub.6 where t is 1 or 2 and R.sub.6 is thienyl, pyrrolyl or furyl optionally substituted by one or two substituents selected from C.sub.1-6 alkyl, C.sub.1-6 alkoxy, trifluoromethyl or halogen, or is phenyl optionally substituted by one or two substituents selected from C.sub.1-4 alkoxy, trifluoromethyl, halogen, nitro, carboxy, esterified carboxy, and C.sub.1-4 alkyl optionally substituted by hydroxy, C.sub.1-4 alkoxy, carboxy, esterified carboxy or in vivo hydrolysable acyloxy.