A compound of the formula ##STR1## wherein R is a straight or branched chain alkyl group having 1 to 17 carbon atoms or a cycloalkyl group having 3 to 6 carbon atoms; as well as the physiologically acceptable acid addition salts thereof. A method of production of the compounds, pharmaceutical compositions containing them, and methods of use are also disclosed. The compounds of the present invention are useful in the treatment of angina pectoris, hypertension, and certain forms of arrhythmia.
A silver halide color photographic material containing a compound capable of the timed release of photographically useful groups is disclosed. The material contains at least one compound of the formula (I): ##STR1## wherein R.sub.1 is an alkyl group; R.sub.2 is an alkyl or aryl group; R.sub.3 is an oxycarbonyl, sulfonamido, carbamoyl, acylamino, ureido, oxycarbonylamino, sulfonyloxy, carbonyloxy or sulfamoyl group; R.sub.4 is a substituent; n is 0, 1, 2 or 3; and X is a group, preferably of the formula (II) or (III), which, when eliminated upon coupling with the oxidation product of a developing agent, forms an o-quinonemethide or p-quinonemethide to release a development inhibitor or a precursor thereof.
