Efficient Synthesis of 2,3,4,5-Tetrahydro-1H-3-benzazepines by Intramolecular Heck Reaction

All articles of this category A new facile method for the synthesis of the pharmacologically interesting 3-benzazepine skeleton is described. The easily available iodinated benzene derivative 3 is alkylated with allyl halides 4a-c to afford compounds 5a-c . Pd-catalyzed Heck-type cyclization leads to 3-benzazepines 6 , 7 , and 8 in 75-92 % yield, with 7 and 8 being mixtures of isomers. Hydrogenation gives uniform 1-alkyl substituted compounds 9a-c , of which 9c is transformed into the derivatives 10 , 11 , and 12 .