Cl.[CH:2]1([CH2:15][C:16]([O:18]CC)=O)[C:7]2[NH:8][C:9]3[C:14]([C:6]=2[CH2:5][CH2:4][NH:3]1)=[CH:13][CH:12]=[CH:11][CH:10]=3.[O-:21][C:22]#[N:23].[Na+].[CH3:25]COCC>O>[CH3:25][N:23]1[C:16](=[O:18])[CH2:15][CH:2]2[C:7]3[NH:8][C:9]4[C:14]([C:6]=3[CH2:5][CH2:4][N:3]2[C:22]1=[O:21])=[CH:13][CH:12]=[CH:11][CH:10]=426 g (0.088 mol) of ethyl 2,3,4,9-tetrahydro-1H-pyrido[3,4-b]indole-1-acetate hydrochloride are dissolved in 1 liter of hot water. The pH should be 4-5. When the temperature of the reaction medium is 50° C., a solution of 8.7 g (0.13 mol) of sodium cyanate in 150 cm3 of water is added. The reaction medium is kept at 50° C., whilst stirring. It is stirred for 4 hours at 50° C. and left to stand overnight at ambient temperature; the supernatant water is drawn off. 200 cm3 of ether are added, the mixture is stirred, the ether solution is then drawn off and the same operation is repeated. The expected product is very soluble in ether. The ether extracts are combined and washed with acidified water, in order to remove traces of the starting material, and then with water. They are dried over Na2SO4 and the solvent is evaporated off. This yields an oil which changes into a foam on more thorough drying. The product is used as such in the following step.
Loading…
