Oxazoleacetic acid derivatives

A compound of the formula:

• ##STR21## wherein R.sup.1' is a group of the formula:
• ##STR22## where R.sup.5' is hydrogen;
• R.sup.6' and R.sup.7' is combined with the neighbouring carbon atom to represent a cycloalkyl group of 3 to 7 carbon atoms;
• R.sup.2 is a straight chain or branched alkyl group of 1 to 6 carbon atoms;
• and R.sup.3 is hydrogen, a straight chain or branched alkyl group of 1 to 6 carbon atoms, or an aralkylgroup, or a pharmaceutically acceptable salt thereof.

A pharmaceutical composition comprising an antidiabetically effective amount of compound of the formula:

• ##STR23## wherein R.sup.1 is (A) a groupd of the formula, ##STR24## where R.sup.4 is hydrogen, a halogen or trifluoromethyl group, or (B) a groupd of the formula, ##STR25## where n is 0 or an integer of 1 to 3;
• R.sup.5 is hydrogen, or a straight chain or branched alkyl group of 1 to 6 carbon atoms;
• R.sup.6 and R.sup.7 are respectively a straight chain or branched alkyl group of 1 to 6 carbon atoms, a straight chain or branched alkenyl group of 2 to 6 carbon atoms, a cycloalkyl group of 3 to 7 carbon atoms, or a cycloalkenyl group of 5 to 7 carbon atoms;
• R.sup.6 and R.sup.7 may be combined with the neighbouring carbon atom to represent a cycloalkyl group of 3 to 7 carbon atoms, a cycloalkenyl group of 5 to 7 carbon atoms, a bicycloalkyl group of 7 to 10 carbon atoms, or a bicycloalkenyl group of 7 to 10 carbon atoms;
• provided, however, that when n is 0 and R.sup.5 is hydrogen, R.sup.6 and R.sup.7 can be combined only to form a cycloalkenyl group of 5 to 7 carbon atoms, a bicycloalkyl group of 7 to 10 carbon atoms, or a bicycloalkenyl group of 7 to 10 carbon atoms;
• R.sup.2 is a straight chain or branched alkyl group of 1 to 6 carbon atoms;
• and R.sup.3 is hydrogen, a straight chain or branched alkyl group of 1 to 6 carbon atoms, or an aralkyl group, or a pharmaceutically acceptable salt thereof, and a pharmaceutically acceptable carrier, diluent or excipient thereof.

A method of treating diabetes by administering a thereapeutically effective amount of a compound of the formula:

• ##STR26## wherein R.sup.1 is (A) a group of the formula, ##STR27## where R.sup.4 is hydrogen, a halogen or trifluoromethyl group, or (B) a group of the formula, ##STR28## where n is 0 or an integer of 1 to 3;
• R.sup.5 is hydrogen, or a straight chain or branched alkyl group of 1 to 6 carbon atoms;
• R.sup.6 and R.sup.7 are respectively a straight chain or branched alkyl group of 1 to 6 carbon atoms, a straight chain or branched alkenyl group of 2 to 6 carbon atoms, a cycloalkyl group of 3 to 7 carbon atoms, or a cycloalkenyl group of 5 to 7 carbon atoms;
• R.sup.6 and R.sup.7 may be combined with the neighbouring carbon atom to represent a cycloalkyl group of 3 to 7 carbon atoms, a cycloalkenyl group of 5 to 7 carbon atoms, a bicycloalkyl group of 7 to 10 carbon atoms, or a bicycloalkenyl group of 7 to 10 carbon atoms;
• R.sup.2 is a straight chain or branched alkyl group of 1 to 6 carbon atoms;
• and R.sup.3 is hydrogen, a straight chain or branched alkyl group of 1 to 6 carbon atoms, or an aralkyl group, or a pharmaceutically acceptable salt thereof.