One-pot synthesis of simple alkaloids: 2,3-polymethylene-4(3H)-quinazolinones, luotonin A, tryptanthrin, and rutaecarpine

One-pot synthesis of various 2,3-polymethylene-4(3H)-quinazolinones from anthranilic acid, corresponding lactam and SOCl2 is described, which can be applicable to the synthesis of simple 4(3H)-quinazolinone-derived alkaloids, such as luotonin A, tryptanthrin, and rutaecarpine.