Diiodomethane → 5-Iodoquinoline

Participants

Reaction Conditions

Reaction Steps

A suspension of 10 g (0.07 mol) of 5- aminoquinoline, 94 ml (0.7 mol) of isoamylnitrite and 100 ml of diiodomethane was heated at 80° C. for 2 hours. The reaction mixture was evaporated under reduced pressure at 60°-70° C. The residue was slurried with diethyl ether, decanted and the filtrate was evaporated under reduced pressure. The resulting residue was chromatographed on a silica gel column eluting with 3:1 hexane-ethyl acetate to yield 2.81 g of 5-iodoquinoline. 1H-NMR (CDC13, 300MHz) δ 7.42(d, 1H, J=7.7 Hz); 7.48 (dd, 1H, J=4.3 Hz); 8.1 (m, 2H,); 8.38 (d, 1H, J=8.5 Hz); 8.88 (m, 1H,). Mass spec. m/e=255=p. ##STR27## 2.18 g (0.022 mol) of triethylamine were added to a suspension of 2.75 g (0.011 mol) of 5-iodoquinoline in acetonitrile (24 ml) and the solution formed on warming. The solution was allowed to cool briefly. To the solution were added 50 mg of triphenylphosphine, 50 mg of palladium(II) acetate and 3.1 ml (0.022 mol) of 3,3- zdiethoxy-1-propyne (propiolaldehyde diethylacetal). The reaction was heated at 80° C. for 1.5 hours. The reaction was poured into water and extracted with hexane. The hexane was removed under reduced pressure and the residue was chromatographed on a silica gel column and eluted with 1% methanol-dichloromethane to yield 1.44 g of 5-quinoline-[l- propiolaldehyde diethyl acetal]. 1H-NMR (CDC13, 300MHz) 6 1.3 (t, 6H, J=7.2 Hz); 3.73 (m, 2H,); 3.88 (m, 2H); 5.62 (s, 1H,); 7.48 (dd, IH, J=8.5 and 4.2 Hz); 7.66 (d, 1H, J=7.4 Hz); 7.76 (d, 1H, J=7.2Hz); 8.1 (d, 1H, J=8.5Hz); 8.6 (d, 1H, J=8.5Hz); 8.94 (m, 1H). Mass spec. m/e=255=p. ##STR28##

Provenance & Evidence