Nonapeptide and decapeptide analogs of LHRH useful as LHRH antagonists

Claim 1

A compound of the formula ##STR11## and the pharmaceutically acceptable salts thereof, wherein: A is an amino acyl residue selected from the group consisting of N-Ac-D,L-Δ 3 ,4 -prolyl, N-Ac-D,L-prolyl, N-Ac-L-alkylprolyl, N-Ac-D,L-phenylalanyl, N-Ac-D,L-p-chlorophenylalanyl, N-Ac-D,L-seryl, N-Ac-D,L-threonyl, N-Ac-D,L-alanyl, 3-(1-naphthyl)-D,L-alanyl, 3-(2-naphthyl)-D,L-alanyl, 3-(2,4,6-trimethylphenyl)-D,L-alanyl, and 3-(4-trifluoromethylphenyl)-D,L-alanyl; B is an amino acyl residue selected from the group consisting of D-phenylalanyl, D-p-Cl-phenylalanyl, D-p-F-phenylalanyl, D-p-nitrophenylalanyl, 3-(3,4,5-trimethoxyphenyl)-D-alanyl, 2,2-diphenylglycyl, D-α-methyl-p-Cl-phenylalanyl and 3-(2,4,6-trimethylphenyl)-D-alanyl; C is an amino acyl residue selected from the group consisting of D-tryptophanyl, D-phenylalanyl, D-Me 5 phenylalanyl, 3-(3-pyridyl)-D-alanyl, 3-(1-naphthyl)-D-alanyl, and 3-(2-naphthyl)-D-alanyl; D is an amino acyl residue selected from the group consisting of L-seryl, and D-alanyl; E is an amimo acyl residue selected from the group consisting of L-phenylalanyl and L-tyrosyl; F is an amino acyl residue selected from the group consisting of the radicals represented by the following structural formulas: (a) ##STR12## wherein n is 1 to 5; R 1 is alkyl of 1 to 12 carbon atoms, --NHR 3 wherein R 3 is alkyl of 1 to 12 carbon atoms, cycloalkyl, phenyl, benzyl, morpholino or --(CH 2 ) n N(R 4 ) 2 wherein n is 1 to 5 and R 4 is lower alkyl; R 2 is R 1 ; or R 1 and R 2 comprise a ring represented by the following structural formulas: ##STR13## wherein n is 1 to 7; A is hydrogen, alkyl of 1 to 6 carbon atoms or cycloalkyl; and X is halo or A or (b) a substituent of the formula ##STR14## wherein R 9 is hydrogen, alkyl of 1 to 12 carbon atoms, phenyl or phenylloweralkyl; G is an amino acyl residue selected from the group consisting of L-leucyl, L-norleucyl and L-norvalyl; H is D-alaninamide, D-leucinamide, glycinamide or --NHR 5 wherein R 5 is lower alkyl or NHCONH 2 .