Method for the treatment of reversible airways obstruction and asthma

A method for the treatment of reversible airways obstruction, in mammals, which method comprises administering to a mammal in need of such treatment an effective amount of a compound of formula (I):

• ##STR4## wherein:
• either one of R.sub.1 or R.sub.2 is hydrogen and the other is C.sub.1-6 alkylcarbonyl, C.sub.1-6 alkoxycarbonyl, C.sub.1-6 alkylcarbonyloxy, C.sub.1-6 alkylhydroxymethyl, nitro, cyano, chloro, trifluoromethyl, C.sub.1-6 alkylsulphinyl, C.sub.1-6 alkoxysulphonyl, C.sub.1-6 alkylcarbonylamino, C.sub.1-6 alkoxycarbonylamino, C.sub.1-6 alkyl-thiocarbonyl, C.sub.1-6 alkoxy-thiocarbonyl, C.sub.1-6 alkyl-thiocarbonyloxy, C.sub.1-6 alkyl-thiolmethyl, formyl, aminosulphinyl, aminosulphonyl or aminocarbonyl, the amino moiety being unsubstituted or substituted by one or two C.sub.1-6 alkyl groups, or C.sub.1-6 alkylsulphinylamino, C.sub.1-6 alkylsulphonylamino, C.sub.1-6 alkoxysulphinylamino, C.sub.1-6 alkoxysulphonylamino or ethylenyl terminally substituted by C.sub.1-6 alkylcarbonyl, nitro, cyano, --C(C.sub.1-6 alkyl) NOH or --C(C.sub.1-6 alkyl)NNH.sub.2, or either one of R.sub.1 or R.sub.2 is nitro, cyano or C.sub.1-3 alkylcarbonyl and the other is methoxy or amino unsubstituted or substituted by one or two C.sub.1-6 alkyl or by C.sub.2-7 alkanoyl;
• either one of R.sub.3 or R.sub.4 is hydrogen or C.sub.1-4 alkyl and the other is C.sub.1-4 alkyl or R.sub.3 and R.sub.4 together are C.sub.2-5 polymethylene;
• R.sub.5 is hydrogen, hydroxy, C.sub.1-6 alkoxy or C.sub.1-7 acyloxy and R.sub.6 is hydrogen, or R.sub.5 and R.sub.6 together are a bond;
• R.sub.7 is hydrogen, C.sub.1-6 alkyl unsubstituted or substituted by hydroxy, C.sub.1-6 alkoxy, C.sub.1-6 alkoxycarbonyl or carboxy, C.sub.1-6 alkyl substituted by halogen, or C.sub.2-6 alkenyl, phenyl, naphthyl or heteroaryl each of which is unsubstituted or substituted by C.sub.1-6 alkoxy, hydroxyl, halogen, trifluoromethyl, nitro, cyano, C.sub.1-12 carboxylic acyl or amino or aminocarbonyl unsubstituted or substituted by one or two C.sub.1-6 alkyl groups and wherein the heteroaryl moiety is selected from the list of groups as defined hereinafter;
• R.sub.8 is hydrogen or C.sub.1-6 alkyl;
• or
• R.sub.7 and R.sub.8 are joined together to form C.sub.3-4 polymethylene or --CH.sub.2 --(CH.sub.2).sub.n --Z--(CH.sub.2)m-- where m and n are integers of 0 to 2 such that m+n is 1 or 2 and z is oxygen, sulphur or NR.sub.9 wherein R.sub.9 is hydrogen, C.sub.1-9 alkyl, C.sub.2-7 alkanoyl, phenyl C.sub.1-4 alkyl, naphthylcarbonyl, phenylcarbonyl or benzylcarbonyl unsubstituted or substituted in the phenyl or naphthyl ring by one or two C.sub.1-6 alkyl, C.sub.1-6 alkoxy or halogen;
• heteroaryl carbonyl;
• and wherein heteroaryl moieties in R.sub.7 and R.sub.9 are selected from the group consisting of furanyl, thiophenyl, pyrryl, oxazolyl, thiazolyl, imidazolyl, thiadiazolyl, pyridinyl, pyridazinyl, pyrimidinyl, pyrazinyl, triazinyl, benzofuranyl, benzothiophenyl, indolyl, indazolyl, quinolinyl, isoquinolinyl and quinazoninyl;
• X is oxygen or sulphur;
• and the R.sub.8 NCXR.sub.7 moiety is trans to the R.sub.5 group when R.sub.5 is hydroxy, C.sub.1-6 alkoxy or C.sub.1-7 acyloxy;
• or a pharmaceutically acceptable salt or hydrate thereof.