NONSOLVATE-FORM CRYSTAL OF POLYMETHINE COMPOUND AND PROCESS FOR PRODUCING THE SAME

摘要

Novel nonsolvate-form crystals of a polymethine compound which are satisfactorily stable in solutions, have a high gram extinction coefficient and excellent storage stability, are easy to handle, and are highly sensitive to common semiconductor lasers. The crystals are nonsolvate-form crystals of a polymethine compound represented by the formula (I). Also provided is a process for producing nonsolvate-form crystals of a polymethine compound represented by the formula (I), which is characterized by reacting a polymethine ether compound represented by the following formula (II) with hydrochloric acid or hydrobromic acid. (In the formula (I), X represents chlorine or bromine.). (In the formula (II), R represents alkyl, alkoxyalkyl, or optionally substituted aryl.)