Microwave Assisted Rapid Synthesis of β -Nitroalcohols

A major concern in base catalyzed Henry reaction for the synthesis of β-nitroalcohol from the reaction of aldehyde and nitroalkane is instantaneous formation of nitroalkene by dehydration, which in turn facilitates many side reactions. It is observed that rapid synthesis of β-nitroalcohol can be accomplished by carrying out the reaction in aqueous phosphate buffer at pH 7.0 under microwave irradiation without using any additional base. Use of microwave irradiation facilitated the formation of β-nitroalcohol within a very short time, yet no instantaneous formation of nitroalkene was observed even at 80 °C.