Novel Method for Preparing Fluorination Reagent and Its Application to Synthesis of Fluoropyridazinones

Abstract

4-Chloro-5-fluoro-2-aryl-3(2H)-pyridazinones were obtained by the fluorination of 4,5-dichloro-2-aryl-3(2H)-pyridazinones with ethylhexamethylenetetramine fluoride in excellent yields. The ethylhexamethylenetetramine fluoride was synthesized by the reaction of hydrofluoric acid with ethylhexamethylenetetramine hydroxide prepared from ethylhexamethylenetetramine bromide and alkali.

Keywords:

• Ethylhexamethylenetetramine fluoride
• fluorination
• halopyridazinones
• onium fluorination reagent

Notes

^a Reaction conditions: 5a (1 mmol), fluorination reagent (2 mmol), solvent (10 mL), 8h.

^b Isolated yield.

^a All products were characterized by ¹H NMR, MS, and IR.

^b Isolated yields.