✍ Scribed by Jose M. Rodríguez; M. Dolors Pujol
No coin nor oath required. For personal study only.
b-Nitroalcohol or nitroethylene derivatives can be obtained from aryl aldehydes and nitromethane under Henry condensation conditions. We present a new modification using microwave irradiation or ultrasound as the energy source. Microwave irradiation allowed a novel one-pot synthesis of nitroolefins from aryl aldehydes using ammonium acetate as a catalyst without solvent. Different reaction conditions, such as base, solvent, and reaction time were studied. Only small amounts of b-hydroxyl nitro compounds were isolated, using microwave irradiation for less than 25 min. In contrast, the use of ultrasound increased the yield of the nitroalcohols.
📜 SIMILAR VOLUMES
In a solventless system and under microwave irradiation, nitroaikanes react with arylaldehydes in the presence of a catalytic amount of ammonium acetate to afford, in one step, conjugated nitroalkenes without the isolation of intermediary ~-nitro alcohols.
Several pyrimido [4,5-b]quinolines, flavin analogues, have been prepared by assisted microwave intramolecular cyclization of N 4 -substituted-2,4-diamino-6-chloropyrimidine-5-carbaldehydes. The reaction takes place with hydrolysis of amino-group and chlorine. Particularly valuable features of this m