Phosphonyl hydroxyacyl amino acid derivatives as antihypertensives

A compound of the formula ##STR431## and pharmaceutically acceptable salts thereof wherein:

• ##STR432## R.sub.4 is hydrogen, lower alkyl, halogen, keto, hydroxy, ##STR433## azido, amino, ##STR434## a 1- or 2-naphthyl of the formula ##STR435## --(CH.sub.2).sub.m --cycloalkyl, ##STR436## --O--lower alkyl, ##STR437## a 1- or 2-naphthyloxy of the formula ##STR438## --S--lower alkyl, ##STR439## or a 1- or 2-naphthylthio of the formula ##STR440##
• R.sub.5 is keto, halogen, ##STR441## --O--lower alkyl, a 1- or 2-naphthyloxy of the formula ##STR442## --S--lower alkyl, ##STR443## or a 1- or 2-naphthylthio of the formula ##STR444## R.sub.7 is keto or ##STR445## each R.sub.8 is the same or different and is halogen or --Y--R.sub.14 ;
• R.sub.11 is hydrogen, lower alkyl of 1 to 4 carbons, lower alkoxy of 1 to 4 carbons, lower alkylthio of 1 to 4 carbons, chloro, bromo, fluoro, trifluoromethyl, hydroxy, phenyl, phenoxy, phenylthio, or phenylmethyl;
• R.sub.12 is hydrogen, lower alkyl of 1 to 4 carbons, lower alkoxy of 1 to 4 carbons, lower alkylthio of 1 to 4 carbons, chloro, bromo, fluoro, trifluoromethyl, or hydroxy;
• m is zero, one, two or three;
• p is one, two or three provided that p is more than one only if R.sub.11 or R.sub.12 is hydrogen, methyl, methoxy, chloro, or fluoro;
• R.sub.13 is hydrogen or lower alkyl of 1 to 4 carbons;
• Y is oxygen or sulfur;
• R.sub.14 is lower alkyl of 1 to 4 carbons, ##STR446## or the R.sub.14 groups join to complete an unsubstituted 5- or 6-membered ring or said ring in which one or more of the carbons has a lower alkyl of 1 to 4 carbons or a di(lower alkyl of 1 to 4 carbons) substituent;
• R.sub.1 is alkyl of 1 to 10 carbons, aminoalkyl, haloalkyl, ##STR447## wherein q is zero or an integer from 1 to 7 and R.sub.11 and p are as defined above;
• and
• R.sub.19 and R.sub.20 are independently selected from the group consisting of hydrogen, lower alkyl, halo substituted lower alkyl, ##STR448## wherein m, R.sub.11 and p are as defined above;
• R.sub.2 is hydrogen, lower alkyl, halo substituted lower alkyl, ##STR449## wherein r is as defined hereinbefore;
• R.sub.3 and R.sub.6 are independently selected from hydrogen, lower alkyl, benzyl, benzhydryl, alkali metal, or ##STR450## wherein R.sub.15 is hydrogen, lower alkyl, cycloalkyl, or phenyl, and R.sub.16 is hydrogen, lower alkyl, lower alkoxy, phenyl, or R.sub.15 and R.sub.16 taken together are --(CH.sub.2).sub.2 --, --(CH.sub.2).sub.3, --CH.dbd.CH-- or ##STR451## R.sub.17 is lower alkyl, benzyl, or phenethyl;
• and R.sub.18 is hydrogen, lower alkyl, benzyl, or phenethyl.