| 摘要 |
PROBLEM TO BE SOLVED: To obtain the subject derivative useful as an antiphlogistic-sedative- drug by cyclizing a specified compound under a specified condition, distilling the reaction solvent, thereafter, adding dimethylformaldehyde and a specified composition, performing an alkylation reaction and hydrolyzing and decarboxylating the product. SOLUTION: This derivative is 2-[4-(2-oxocyclopentan-1-ylmethyl)phenyl] propionic acid (general name; loxoprofen) of formula IV and obtained by subjecting a compound of the formula R'O2CCH2CH2CH2CH2COR' (R' is a lower alkyl) to cyclization reaction in N-N-dimethylformaldehyde in the presence of an alkali metal alkoxide to obtain a compound of formula I, distilling off the reaction solvent therefrom, then adding N-N-dimethylformaldehyde and a compound of formula II (R2 is a lower alkyl; X is a halogen), subjecting to alkylation reaction of an active methylene group at 25-70 deg.C to obtain a compound of formula III and subjecting the compound to hydrolysis and decarboxylation reaction. |
