The invention belongs to the field of
organic chemistry, and discloses a synthetic method for
nicotinamide. The method comprises the following steps: using
ethanol as a
solvent, using 3-methylpyridineas a
raw material, introducing a dried
nitrosyl chloride gas, performing a photonitrosation-
isomerization reaction under
irradiation of visible light at temperature of 0-30 DEG C, after the reactionis completed, introducing a
nitrogen gas, adding an alkali to adjust pH of the reaction solution to be 6-9, and performing
filtration to obtain a filtrate; and adding a
copper salt and a
nitrile intothe filtrate as a catalyst, performing heating, performing
reflux, performing an aldoxime
Beckmann rearrangement reaction, after the reaction is completed, adding
ethyl acetate crystals into the reaction solution, performing
filtration to obtain a crude product of the
nicotinamide, and performing recrystallization on the crude product of the
nicotinamide to obtain a pure product of the nicotinamide. The synthetic method provided by the invention has mild
reaction conditions, a simple process and a high yield, can obtain the high-purity nicotinamide product, has less three waste (waste water, waster gas and
solid waste) and high economy, and is suitable for industrialized large-scale production.