Facile and efficient aromatization of 1,4-dihydropyridines with M(NO3)2·XH2O, TNCB, TBAP and HMTAI and preparation of deuterium labeled dehydronifedipine from nifedipine-d3

Facile aromatization of various 1,4-dihydropyridines was investigated using metal nitrates, TBAP, TNCB and HMTAI as oxidants. Efficient conversion of nifedipine-d3 to dehydronifedipine-d3 as an internal standard.