An Efficient and Environmentally Benign Protocol for the 1,6-Michael Addition of Nitroalkanes to 3-Methyl-4-nitro-5-styrylisoxazoles in WERSA

Herein, we describe a mild and convenient protocol for Michael addition of nitroalkanes to 3-methyl-4-nitro-5-styrylisoxazoles using neat water extract of rice straw ash (WERSA) as a catalyst and medium at room temperature. Method developed is simple to operate and yields range from good to excellent. This eco-friendly protocol also successfully used for the synthesis of pharmaceutical interest, such as gamma-nitrobutyricacid an intermediate for the preparation of Baclofen.