Studies Directed at the Synthesis of Trialkoxysilyl Substituted NLO Chromophores

by Kuhr, Ida J.

Kuhr,Ida J. M.S.,Department of Chemistry,Wright State University,2000. Studies Directed at the Synthesis of Trialkoxysilyl Substituted NLO Chromophores. The synthesis of trialkoxyalkyl substituted NLO chromophores has been investigated. The chromophore 2-(7-(3-hydroxydiphenylamino)-9,9-diethyl-2-fluorenyl)-benzothiazole was prepared by a five step process. Bromination of fluorene yielded 2,7-dibromo-fluorene which could be converted to 2,7-dibromo-9,9-diethylfluorene by alkylation with ethyl iodide in DMSO.Reaction of 2,7-dibromo-9,9-diethylfluorene with one equivalent of butyl lithium followed by reaction with DMF provides 2-bromo-7-formyl-9,9-diethylfluorene. Condensation of 2-bromo-7-formyl-9,9-diethylfluorene and 2-aminobenzenethiol in DMSO results in the formation of 2-(7-bromo-9,9-diethyl-2-fluorenyl)benzothiazole. The conversion of 3-hydroxydiphenylamine to 3-benzyloxy-diphenylamine was accomplished with benzyl bromide and potassium carbonate in DMF. A palladium catalyzed coupling of 3-benzyloxydiphenylamine and 2-(7-bromo-9,9-diethyl-2-fluorenyl)benzothiazole provided 2-(7-(3-hydroxydiphenyl-amino)-9,9-diethyl-2-fluorenyl)benzothiazole. Several attempts to alkylate 2-(7-(3-hydroxydiphenylamino)-9,9-diethyl-2-fluorenyl)benzothiazole with trimethoxysilylmethyl chloride were made but the alkylation product could not be isolated and appeared to be unstable.