97679-32-8Relevant academic research and scientific papers
1,2-Didehydrophenothiazines: Preparation of 1-Alkyl and 1-Aryl-substituted Phenothiazines by Lithium-directed Alkylation
Hallberg, Anders,Dunbar, Philip,Hintermeister, Nalukui Mwisya,Svensson, Arne,Martin, Arnold R.
, p. 969 - 972 (2007/10/02)
A general route to 1-alkyl substituted phenothiazines is described.Reactions of 2-chlorophenothiazine with an excess of methyl-, n-butyl-, s-butyl-, t-butyl- or phenyl-lithiums give the corresponding 1-substituted phenothiazines via 10-lithio-1,2-dehydrophenothiazine.Attempts to trap the presumed 1,10-dilithio intermediate failed.The reaction of 1-chlorophenothiazine with s-butyl-lithium results in preferential metallation of the 9-position. 2-Chlorophenothiazine reacts with nitrogen nucleophiles (lithium dialkylamides) to give 2-substituted products.
