One-Pot Multicomponent Synthesis of 3-Methyl-4-(Hetero)Arylmethylene Isoxazole-5(4H)-Ones Using Guanidine Hydrochloride as the Catalyst under Aqueous Conditions

Here, we have developed an expeditious and efficient protocol for the synthesis of isoxazole-5(4H)-ones derivatives using guanidine hydrochloride as a catalyst using water as a solvent. The one-pot multicomponent reaction of aldehydes, ethyl acetoacetate, and hydroxylamine hydrochloride at room temperature to give a 3-methyl-4-(hetero)arylmethylene isoxazole-5(4H)-ones derivatives in an excellent yield. The key advantages of the reported method are shorter reaction time, energy-efficient, easy work-up procedure, wide substrate scope tolerance, economical, etc. further the catalyst was recycled up to 5 times along with high product yield without significant loss of its catalytic activity.

Automated summary

An expeditious and efficient protocol for the synthesis of isoxazole-5(4H)-ones derivatives has been developed using guanidine hydrochloride as a catalyst in water. The method offers shorter reaction time, energy-efficient, easy work-up procedure, wide substrate scope tolerance, and economical advantages. Additionally, the catalyst can be recycled up to 5 times with high product yield and without significant loss of catalytic activity.