A method of treatment or prophylaxis of angina in mammals, such as humans, which comprises the administration to the sufferer of an effective amount of a compound of formula (I), or a pharmaceutically acceptable salt thereof, or a solvate of any of the foregoing: ##STR1## wherein R.sub.1, R.sub.2, R.sub.3, R.sub.4, A and B are herein defined.
This is a continuation of U.S. application Ser. No. 07/845,522, filed Mar. 4, 1992; now abandoned, which is a continuation of Ser. No. 07/514,675, filed Apr. 25, 1990; now abandoned, which is a continuation of Ser. No. 07/014,474, filed Feb. 13, 1987; abandoned.
A process for preparing a compound of formula (I) or an addition salt thereof and/or a solvate thereof: ##STR1## wherein R.sup.1, R.sup.2, R.sup.4 and R.sup.5 are each independently C.sub.1-4 alkoxy and R.sup.3 is C.sub.1-6 alkyl, which process comprises reacting an arylamine of formula (II): ##STR2## wherein R.sup.4 and R.sup.5 are as defined in relation to formula (I) with a .beta.-aminoaldehyde of formula (III): ##STR3## wherein R.sup.1, R.sup.2 and R.sup.3 are as defined in relation to formula (I); and thereafter reducing the intermediate so formed and, optionally, forming an addition salt of the compound of formula (I) and/or a solvate thereof.
