Syntheses from Pyrimidines

Abstract

Coupling of 4,5-diiodophthalonitrile with rerr-butyldimethylsilylacetylene and a palladium catalyst gave 4,5-bis(rerr-butyldimethylsilylethynyl)phthalonitrile. Cleavage of the silyl moiety with tetftibutylammonium fluoride gave 4,5-diethynylphthalonitrile, while condensation in 2-N,N-dimethylami-noethanol without or with Zn(OAc)2 gave metal-free 2,3,8,9,16,17,23,24-wtakis(tert-butyldimethylsilylethy-nyl)phthalocyanine or its zinc derivative. Cleavage of the silyl groups of the zinc derivative gave an insoluble product whose tH NMR spectrum was indicative of 2,3,9,10,16,17,23,?A.-octaettrynylphthalocyaninato zinc(Il). Bromination of phthalonitrile withN,lV{ibromoisocyanuric acid gave a separable mixture of 3,6-,3,21-and 4,S-dibromophthalonitrile along with the monobromophthalonitrites. Coupling of 3,4dibromophalonitrile with ren-butylacetylene gave 3,4-bis(ren-butylethynyl)phthalonitrile, which on condensation with lithium l-pentanolate gave 1,2,8,9,15,16,22,23-octzkjs(3,3-dimethyl-l-butynyl)phthalocyanins as a single isomer, the first known 1,2,8,9,15.16,22,23-octasubstituted phthalocyanine.