抄録
1-Cyano-2-methoxy (or ethoxy)-1, 2-dihydroquinoline (4a, b) was obtained in a high yield by the reaction of quinoline (1) with cyanogen bromide in methanol (or ethanol) or by the reaction of 1-cyano-2-hydroxy-1, 2-dihydroquinoline (2) in methanol (or ethanol). 3-Bromo-1-cyano-2, 4-dimethoxy (or diethoxy)-1, 2, 3, 4-tetrahydroquinoline (5a, b), obtained in a high yield by the application of bromine to 4a, b in methanol (or ethanol), followed by reaction with sodium carbonate, was reacted with conc. hydrochloric acid in methanol, and 3-bromoquinoline (7) was obtained quantitatively. 7 was also obtained by the application of sodium borohydride to 5a in ethanol. Reaction mechanism for these reactions was considered from some byproducts obtained at the same time. This reaction condition was applied to 2-, 4-, 6-, 7-, and 8-methylquinolines, and 3-bromomethylquinolines (16, 23-25), which were difficult to synthesize, were obtained in a high yield from 4-, 6-, 7-, and 8-methylquinolines (14, 17-19), via 3-bromo-1-cyano-2, 4-dimethoxymethyl-1, 2, 3, 4-tetrahydroquinolines (15, 20-22). 2-Methylquinoline (quinaldine) (26) formed ω-dibromoquinaldine (27) by reaction with cyanogen bromide in methanol and could not be derived to 3-bromoquinoline (28).
