By-product formation in the synthesis of chromium(III) chelates of β-diketones

Abstract

A comparison is made of three common synthetic methods in the preparation of the chromium(III)chelate of 1,1,1-trifluoro-5,5-dimethylhexane-2,4-dine. One of these methods, involving homogeneous reaction with urea, is limited in general use by the possibility of reaction between urea and certain β-diketones to form insoluble, substituted pyrimidinones. Some specificity is demonstrated in the reaction, notably with pentane-2,4-dione and 4,4,4-trifluoro-1- pentafluorophenylbutane-1,3-dione.