Antagonists of endothelin receptors

A compound of formula (I) ##STR46## Ar represents a direct bond or arylene;

• m is 0, 1, 2, or 3;
• R.sub.1 is lower alkyl, cycloalkyl-lower alkyl, aryl-lower alkyl, cycloalkyl, aryl, aryl-cycloalkyl, lower alkoxy, or aryloxy;
• R.sub.2 is hydrogen, lower alkyl, aryl-lower alkyl, cycloalkyl, or cycloalkyl-lower alkyl;
• R.sub.3 represents hydrogen, hydroxy, amino, nitro, lower alkyl, cycloalkyl, or aryl-lower alkyl, provided that Ar is a direct bond, or represents aryl;
• R.sub.3 ' represents hydrogen, lower alkyl, cycloalkyl, aryl-lower alkyl, or aryl;
• or
• R.sub.3 and R.sub.3 ' together form a ring structure, provided that Ar is a direct bond;
• R.sub.3 " is hydrogen, lower alkyl or aryl;
• or
• R.sub.2 and R.sub.3 " together form the lower alkylene group --(CH.sub.2).sub.n -- wherein n is an integer of 1, 2 or 3;
• or
• R.sub.2 and R.sub.3 " together form a group represented by the formula:
• --(CH.sub.2).sub.o --Ar.sub.1 -- or --Ar.sub.1 --(CH.sub.2).sub.o --, respectively, wherein o is zero or an integer of 1 or 2, and Ar.sub.1 is arylene;
• C(.dbd.X) is C(.dbd.O), C(.dbd.S), C(.dbd.NH), C(.dbd.N-lower alkyl);
• C.dbd.NH--OH, or CH.sub.2;
• and Y is a direct bond, --NH--, ##STR47## oxygen, or methylene;
• or C(.dbd.X) is CHOH and Y is a direct bond or methylene;
• R.sub.4 is lower alkyl, lower alkenyl, cycloalkyl, aryl-lower alkyl, aryl-lower alkenyl, or aryl;
• R.sub.5 is hydrogen, lower alkyl, aryl-lower alkyl, cycloalkyl, or cycloalkyl-lower alkyl;
• R.sub.6 represents lower alkyl, halo-lower alkyl, hydroxy-lower alkyl, acyloxy-lower alkyl, lower alkoxy-lower alkyl, aryloxy-lower alkyl, aryl-lower alkyl, lower alkenyl, lower alkenyl which substituted by at least one substituent selected from the group consisting of carboxy, lower alkoxycarbonyl, hydroxy, lower alkoxy, amino, lower alkylamino and di-lower alkylamino, or represents aryl-lower alkenyl, aryl or lower alkyl which is substituted by carboxy or lower alkoxycarbonyl and also by amino, lower alkylamino or di-lower alkylamino;
• or
• R.sub.5 and R.sub.6 together form the lower alkylene group --(CH.sub.2).sub.p -- wherein p is an integer of 3-5, or together form a group represented by the formulae:
• --(CH.sub.2).sub.q --Ar.sub.1 -- or --Ar.sub.1 --(CH.sub.2).sub.q --, wherein q is zero or an integer of 1 or 2, and Ar.sub.1 is arylene;
• and
• Y.sub.1 represents --SO.sub.2 --, --O--, --NH--, --NH--CO--, --NH--CO--O-- or --NH--SO.sub.2 --;
• and wherein "aryl", it being a mono- or bivalent aryl radical or aryl moiety, respectively, represents, in each case, a corresponding carbocyclic or heterocyclic aryl radical or aryl moiety, respectively;
• or a salt thereof.