| abstract |
There is provided a process for producing a thiazolidinedione derivative having excellent prophylactic and therapeutic effects on a disease caused by insulin resistance with a high purity; a process for producing a compound represented by the general formula (A) or a salt thereof, comprising converting 4-[(2,4-dioxothiazolidin-5-yl)methyl]phenoxyacetic acid represented by the following formula into a compound of the general formula (I), wherein X = a halogen atom; then reacting the compound with a compound represented by the general formula (II), wherein R 1 , R 2 , R 3 and R 4 = a hydrogen atom, a hydroxyl group, C1-C6 alkyl, C1-C6 alkoxy, benzyloxy, acetoxy, trifluoromethyl or a halogen atom, R 5 = C1-C6 alkyl, and R 6 = a protecting group for an amino group, to produce a compound represented by the general formula (III); and subsequently cyclizing the compound into the final product, and crystals of a compound represented by the general formula (A) or a salt thereof. |