A NOVEL-APPROACH TO 1-ARYL-2-(P-TOLYLAZO)ALKENES FROM ALKYL ARYL KETONES

1-Aryl-2-(p-tolylazo)alkenes were synthesized starting from alkyl aryl ketones in good overall yield. The employed three-step procedure invo lves: i) alpha-p-tolylhydrazonylation of ketone enolates with tert-but yl p-tolylazosulfide 1; ii) selective reduction of the carbonyl functi on of the obtained alpha-p-tolylhydrazono ketones 3 with NaBH4; iii) d ehydration of the ensuing hydrazono alcohols 4 either in an Et2O/dil. H2SO4 two-phase system or in pyridine/acetic anhydride. (C) 1998 Elsev ier Science Ltd. All rights reserved.