Patent ID: 7153972

Claim:
A method for producing a compound represented by the formula: wherein the ring A is a benzene ring which may be substituted in addition to the group of —COOR 6 group; R 1 is hydrogen or an optionally substituted hydrocarbon residue; X is a direct bond or a spacer having an atomic length of two or less between the phenylene group and the phenyl group; Y is —O—, —S(O)m- or —N(R 4 )— wherein m is an integer of 0, 1 or 2 and R 4 is hydrogen or an optionally substituted alkyl group; R 6 is a lower (C 1-6 ) alkyl optionally substituted with lower (C 2-6 ) alkanoyloxy, 1-lower (C 1-6 ) alkoxycarbonyloxy; n is an integer of 1 or 2; or a pharmaceutically acceptable salt thereof, which comprises; (i) reacting a compound represented by the formula: wherein each symbol has the same meaning as defined above, or a pharmaceutically acceptable salt thereof with an alkylating agent to give a compound represented by the formula: wherein R is triphenylmethyl, 2-tetrahydropyranyl, methoxymethyl or ethoxymethyl and other symbols have the same meanings as defined above, or a pharmaceutically acceptable salt thereof; (ii) reacting the compound (Io) or a pharmaceutically acceptable salt thereof with an alkylating agent to give a compound represented by the formula: wherein each symbol has the same meaning as defined above; or a pharmaceutically acceptable salt thereof; and then, (iii) deprotecting the compound (Ip) or a pharmaceutically acceptable salt thereof.