[Omim][BF4], a green and recyclable ionic liquid medium for the one-pot chemoselective synthesis of benzoxazinones

An efficient procedure for the one-pot chemoselective synthesis of 2H-benzo[b][1,4]oxazin-3(4H)-one derivatives from their corresponding o-aminophenols is developed using DBU in the ionic liquid [omim][BF4]. Upon completion of the reaction and separation of the product, the ionic liquid is recovered and successfully reused over nine recycles without any noticeable loss of performance. (C) 2010 Elsevier Ltd. All rights reserved.