Vilsmeier-Haack reaction of tertiary alcohols: formation of functionalisedpyridines and naphthyridines

Vilsmeier-Haack reaction of 2-arylpropan-2-ols proceeds with multiple imino alkylations leading to the formation of conjugated iminium salts which on a mmonium acetate-induced cyclisation afford 4-arylnicotinaldehydes in good y ields. Tertiary alcohols derived from aliphatic or alicyclic ketones by the addition of methyl Grignard are converted into substituted pyridines and n aphthyridines by the action of Vilsmeier's reagent in N,N-dimethylformamide followed by nucleophile-assisted cyclisation in the presence of ammonium a cetate.