| 主权项 |
1. A method of producing a compound represented by the formula [3]: wherein R1 is an alkyl group, an aralkyl group or an aryl group, each of which is optionally substituted, or a salt thereof, or the formula [4]: wherein the symbol is as defined above, or a salt thereof, comprising (i) reducing a compound represented by the formula [1]: wherein R1 is as defined above, each R2 is an alkyl group, an alkoxy group or a nitro group, or two alkoxy groups are optionally bonded to form an alkylenedioxy group, and p is an integer of 0 to 5, or a salt thereof, or a compound represented by the formula [2]: wherein each symbol is as defined above, or a salt thereof, in the presence of a metal catalyst and an alkaline earth metal salt, or (ii) reacting a compound represented by the formula [1] or a salt thereof or a compound represented by the formula [2] or a salt thereof with 0.1 equivalents-50 equivalents of Brønsted acid relative to compound [1] or compound [2]. |
