Hydrochloric Acid → HCID 12901730, compound

Participants

Reaction Steps

3,4-Dihydropyrazino[2,1-a]isoindole-1,6(2H,10bH)-dione (described in Example 6, 14 g, 0.0674 mol) is added portionwise to 700 ml of 1 M borane in tetrahydrofuran over a 0.5 hr period and then refluxed with stirring for 18 hr. The reaction is cooled, water is added dropwise until the hydrolysis is complete and then 140 ml of 6 N hydrochloric acid is added cautiously. Most of the tetrahydrofuran is distilled off until the distillation temperature reaches 90° C. Then 6 N sodium hydroxide (140 ml) is added and the solution is extracted with chloroform. The chloroform extract is washed with water, dried and evaporated to give the title compound (10 g), nmr (CDCl3) δ 2.63(s), 2.6-4.3(m) and 7.3(m). The title compound is treated with a solution of hydrogen bromide in diethyl ether to give a solid. The solid is crystallized from ethanol to obtain the hydrobromide salt of the title compound, mp 155°-160° C. The title compound (8.9 g) is dissolved in a solution of ethanol containing maleic acid (6.45 g), charcoal is added and the mixture is filtered. The filtrate is evaporated and the residue is crystallized from ethanol-diethyl ether to obtain the maleate salt of the title compound, mp 133°-136° C., Anal. Calc'd. for C11H14N2.C4H4O4 : C, 62.06%, H, 6.25% N, 9.65% and Found: C, 62.00% H, 6.29% N, 9.70%.

Provenance & Evidence