We wish to report the formation of interesting title compounds from the dialdehydes & which became available to us along with the monoaldehydes 2 from 1-methyl-3,4-dihydro- isoquinolines by a Vilsmeier reactionl. Our objective was the construction of the IF&iso- quino[2,1-b](2,7]naphthyridin -8-one ring system :, present in the Alangium alkaloids2 by means of a Hantzsch-type pyridine synthesis from 2 or & Reaction of 2 (R=R,=H) with methyl acetoacetate and ammonia ...
[Larsen, Robert D.; Reamer, Robert A.; Corley, Edward G.; Davis, Paul; Grabowski, Edward J. J.; et al. Journal of Organic Chemistry, 1991 , vol. 56, # 21 p. 6034 - 6038]
