Abstract: Compounds having the formula ##STR1## and pharmaceutically acceptable salts thereof wherein R represents 6,7-di(lower alkoxy) or 6,7,8-tri(lower alkoxy);m is 1 or 2,X is --CHR.sup.1 -- or --CH.sub.2 CH.sub.2 --;each R.sup.1 and R.sup.0 may be the same or different and is hydrogen or lower alkyl;each of R.sup.2 and R.sup.3 is hydrogen, lower alkoxy, lower alkyl, halogen, lower alkanoyl, lower alkoxycarbonyl, --CONR.sup.4 R.sup.5 or --SO.sub.2 NR.sup.4 R.sup.5 wherein each of R.sup.4 and R.sup.5 is hydrogen or lower alkyl;processes for their preparation; and their use as regulators of the cardiovascular system, and particularly in the treatment of hypertension.

Abstract: 6,7-Dialkoxy-4-[4-(substituted)piperidino]quinazolines wherein the 4-substituent is -(CHR.sup.1).sub.m -Z wherein R.sup.1 is hydrogen or lower alkyl; m is 1 or 2, with the proviso that when m is 2, each R.sup.1 can be the same or different; Z is -N(R.sup.2)COR.sup.3, -OCONR.sup.4 R.sup.5, N(R.sup.2)SO.sub.2 R.sup.3 or -N(R.sup.2)CONR.sup.4 R.sup.5 wherein R.sup.2 is hydrogen or lower alkyl; R.sup.3 is lower alkyl, benzyl or phenyl; and each of R.sup.4 and R.sup.5 is hydrogen or is selected from group R.sup.3 ; and methods for their preparation. The compounds are phosphodiesterase inhibitors and cardiac stimulants.