反应详情

For example, 5-bromo3-hydroxy-2 (1H)-pyridinone is protected as the 3-t-butyloxycarbonyl derivative (by treatment with di-t-butyl dicarbonate) and treated with e.g. an appropriately substituted benzyl bromide in the presence of silver carbonate in an inert solvent such as toluene. The resulting 2-benzyloxy substituted derivative is then reacted with cuprous cyanide in an inert solvent such as DMF at elevated temperature to yield 6-benzyloxy-5-hydroxynicotinonitrile. Condensation with a Grignard reagent (e.g. methylmagnesium bromide) yields 6-benzyloxy-5-hydroxy-3-acetylpyridine which is further reacted, with e.g. ethyl bromoacetate, to give the starting material for the Horner-Emmons condensation of process (a).