Phamacologically active 5-carboxy-2-(5-tetrazolyl) pyridines

A member selected from the group consisting of

• (a) a compound of formula ##STR6## wherein A represents 5-tetrazolyl which is unsubstituted or is substituted in the 2-position by a member selected from the group consisting of (1) C.sub.1 -C.sub.20 alkyl, (2) amino-lower alkyl, (3) mono-lower alkylamino-lower alkyl, (4) di-lower alkylamino-lower alkyl, (5) carboxy-lower alkyl, (6) lower alkoxycarbonyl-lower alkyl, (7) aryl-lower alkyl, (8) hydroxy-lower alkyl, (9) lower alkanoyloxy-lower alkyl, (10) lower alkoxy-lower alkyl, (11) hydroxy-lower alkoxymethyl, (12) lower alkanoyloxy-lower alkoxymethyl, (13) lower alkoxy-lower alkoxymethyl, (14) 1-alkoxycarbonyl-1-lower alkoxy-methyl, (15) 3-phthalidyl, (16) lower alkyl-3-phthalidyl, (17) lower alkoxy-3-phthalidyl, (18) halogen-3-phthalidyl, (19) lower alkoxycarbonyloxy-lower alkyl and (20) lower alkanoyl;
• R.sub.1 represents carboxy or a pharmaceutically acceptable ester group thereof;
• R.sub.2 represents hydrogen or a member selected from the group consisting of lower alkyl, cycloalkyl, aryl-lower alkyl, heteroaryl-lower alkyl and aryl each of which members can be unsubstituted or substituted;
• and
• R.sub.3 represents hydrogen;
• (b) a tautomer thereof and (c) a pharmaceutically acceptable salt thereof.