| 摘要 |
<p>Method for the preparation of 3-unsubstituted 2,3,4,4a,5,6-hexahydro-1H-pyrazino (1.2-a)quinolines (I). where R1 = nitro, amino, acylamino, hydroxyl, acyloxy, alkyl, alkoxy, and alkenyloxy, halogen, and trifluoromethyl. R2 and R3 = H or lower straight or branched alkyl. n, and p = 0,1,2, or 3. The compounds act on the CNS, in particular, they have antihypertensive activity. 250 ml acetic acid and 30ml 8N HCl in ethanol is added to a solution of 95 g 3-benzyl-8-methyl-2,3,4,4a,5,6-hexahydro -1H-pyrazino (1.2-a) quinoline in 500 ml ethanol, and the solution is hydrogenated in the presence of 4 g 10% palladium/charcoal until the theoretical amount of hydrogen is taken up. The catalyst is filtered off and the filtrate is evaporated to dryness, followed by adding ice water to the residue and 10 N NaOH solution until the mixture is alkaline. The base is extracted with dichloromethane and the organic phase is washed with water and dried on sodium sulphate. The solvent is removed to give 8-methyl-2, 3, 4, 4a, 5, 6-hexahydro-1H-pyrazino (1.2-a) quinoline, which is a yellow oil, b.p. 95-100 deg.C at 0.07 mm Hg.</p> |
