ELECTROPHILIC SUBSTITUTION IN N-ARYL-2-PYRAZOLINES: REACTIONS WITH 1,3-DITHIOLES

Article abstract of DOI:10.1007/BF00505601

Dyes that absorb at 525-580 nm were obtained by the reaction of derivatives of 1,3-dithiolium iodide (or perchlorate) with 1-phenyl-3,5-di-R-2-pyrazolines, N,N-dimethylaniline, and benzaldehyde N-methylphenylhydrazone.It was demonstrated by alternative synthesis that the reaction takes place in the para position of the N-phenyl group.Dyes can be obtained in two steps from 2-dimethylamino-1,3-dithioles and activated aromatic compounds with subsequent oxidation of the intermediate leuco compounds with air oxygen.