Process for production of biphenyl derivative

A production method of a biaryltetrazole derivative represented by the formula [I]:

• wherein X2 is a halogen atom, and R1 is a tetrazolyl-protecting group selected from a C7-19 aralkyl group, a substituted C7-19 aralkyl group and a trialkylsilyl group, or a salt thereof, which comprises
• 1) reacting an aryltetrazole derivative represented by the formula [II]:
• wherein R1 is as defined above with a benzene derivative represented by the formula [III]:
• wherein R2 is a methyl group, a methyl group substituted by hydroxyl group(s) protected by a protecting group, or a lower alkoxycarbonyl group, and X1 is a leaving group selected from a halogen atom, a C6-10 arylsulfonyloxy group optionally substituted by 1 to 3 C1-6 alkyl groups and a C1-6 alkylsulfonyloxy group optionally substituted by 1 to 3 halogen atoms in the presence of a ruthenium catalyst, a ligand and a base;
• 2) in the obtained compound represented by the formula [IV]:
• wherein the symbols are as defined above,
• (a) deprotecting the compound wherein R2 is a methyl group substituted by hydroxyl group(s) protected by a protecting group, or
• (b) reducing the compound wherein R2 is a lower alkoxycarbonyl group, to give a compound represented by the formula [V]:
• wherein the symbol is as defined above;
• and
• 3) halogenating
• the compound represented by the formula [IV] wherein R2 is a methyl group, or
• the compound represented by the formula [V] when R2 in the compound represented by the formula [IV] is a methyl group substituted by hydroxyl group(s) protected by a protecting group, or a lower alkoxycarbonyl group.