A method for preparing 1-aryl-3-arylamino-2-pyrazolin-5-ones
申请人:EASTMAN KODAK COMPANY
(a New Jersey corporation)
公开号:EP0076212A2
公开(公告)日:1983-04-06
A method for preparing a 1-aryl-3-arylamino-2-pyrazolin-5-one comprises reacting an N-aryl-3-arylamino-3- oximinopropionamide with an acylating agent in an inert solvent, then heating in contact with a strong acid catalyst and a dehydrating agent in an inert solvent, and then heating in contact with an acid in water and a lower alkanol. The 1-aryl-3-arylamino-2-pyrazolin-5-one may be used as a color-forming coupler or as an intermediate in preparing a color-forming coupler which produces a dye in a photographic element.