207. Photo-Emde Degradation of 1,2,3,4-Tetrahydroquinolinium Salts

Article abstract of DOI:10.1002/hlca.19850680721

It is shown that 1,1-dimethyl-1,2,3,4-tetrahydroquinolinium ions undergo, under direct irradiation through quartz in CH3OH and independent of the nature of the counterion (I^-, BF4^-), a reductive cleavage of the N(1)-C(8a) bond (photo-Emde degradation).The corresponding N,N-dimethyl-3-phenylpropylamines are formed in high yields and without contamination by Hofmann degradation products of the tetrahydroquinolinium salts.Me groups at C(2) as well as substituents at C(6) (CH3, Cl, CH3O) favour the photo-Emde degradation.The aromatic Cl-substituent is reductively split off in the course of the photoreaction.