| abstract |
The invention concerns compounds of the formula <CHEM> wherein R is C3-7 alkyl, C3-7 cycloalkyl, <CHEM> <CHEM> R<1> is hydrogen, lower alkyl or <CHEM> a is 1-3; b is 1-3; c is 0-2; X, Y and Z are each independently, a bond, O, S or NH, with the proviso that if one of X or Y is O, S or NH, the other must be a bond; R<2> is amino, loweralkylamino, arylamino, loweralkoxy or aryloxy; R<3> and R<3 min > are independently is hydrogen, halo, hydroxy, lower alkoxy, aryloxy, loweralkanoyloxy, amino, lower alkylamino, arylamino or loweralkanoylamino; R<4> and R<5> are each independently hydrogen or lower alkyl; m is 0-4; n is 1-4; and o is 1-4, and oxime and ketone intermediates thereto. The compounds of formula I selectively inhibit an isoenzyme of 3 min :5 min -cyclic AMP phosphodiesterase located in pulmonary smooth muscle tissue and inflammatory cells and are bronchodilatory or anti-inflammatory and so are useful in the treatment of acute and chronic bronchial asthma as associated pathologies. |