| abstract |
Disclosed is a method for purifying (Z)-11-(3-dimethylaminopropylidene)-6,11-dihydrodibenz- [b,e]oxepin-2-acetic acid represented by the formula [I] or an acid addition salt thereof, which comprises dissolving (Z)-11-(3-dimethylaminopropylidene)-6,11-dihydrodibenz- [b,e]oxepin-2-acetic acid or the acid addition salt thereof in a mixed solvent of water and a ketone solvent and causing a crystal to be precipitated from the solution. The method can purify (Z)-11-(3-dimethylaminopropylidene)-6,11-dihydrobenz[b,e]- oxepin-2-acetic acid, which is useful as a medicinal substance, or an acid addition salt thereof efficiently in an industrially advantageous manner. |