Electrochemical C–H Arylation of Quinazolinone with Aryl Tetrafluoroborate Diazonium Salts in Aqueous Solution of Ionic Liquids

Abstract

A process for the electrochemical direct C−H arylation of quinazolinones and aryl tetrafluoroborate diazonium salts with ionic liquid [EMIM]BF 4 (1-ethyl-3-methylimidazolium tetrafluoroborate):H 2 O (2:1) as electrolyte was developed for the synthesis of 2-arylquinazolinones, and a series of 2-arylquinazolinones were synthesized with moderate to good yields. This method was applied for the synthesis of a key intermediate of an IKK β inhibitor CU160 and a quinazolinone alkaloid 2-(1H-indol-3-yl) quinazolin-4(3H)-one. The mild and green synthesis scheme provides an effective alternative to the traditional synthesis of 2-arylquinazolinone.

Electroreduction strategy: a sustainable tool for the generation of aryl radicals

“…Furthermore, in 2023, Chu et al disclosed a similar electroreductive heteroarylation of aryl diazonium salts with quinazolinones in an aqueous solution of an ionic liquid, [EMIM]BF 4 (1-ethyl-3-methylimidazolium tetrafluoroborate), enriching the application of aryl diazonium salts in C(sp 2 )–C(sp 2 ) cross-coupling reactions (Scheme 30). 65…”