2,3,4,10b-tetrahydro-1H-pyrazino[1,2-b]isoindol-6-one

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A solution of 1,2,3,4,6,10b-hexahydropyrazino[2,1-a]isoindol-6-one (described in Example 8, 7.5 g, 0.04 mol) in 150 ml of benzene is added to sodium hydride (1.7 g of a 50% dispersion in mineral oil, 0.036 mol) in 200 ml of benzene and stirred at room temperature for 30 min. A solution of ethyl bromoacetate (8.8 g, 0.044 mol) in 150 ml of benzene is added and the reaction is refluxed with stirring for 3 hr and cooled. Water is cautiously added and the benzene layer is separated, washed with water, dried, and evaporated. The residue is chromatographed on silica gel using 50% acetone in benzene and the eluates are evaporated to give 6-oxo-1,2,3,4,6,10b-hexahydropyrazino[2,1-a]isoindole-1-acetic acid ethyl ester (5.5 g), nmr (CDCl3) δ1.3(t), 2.4-2.6(m), 2.8-3.5(m), 4.2(q), 4.6(m) and 7.3-7.7(m). the reaction is refluxed with stirring for 3 hr cooled the benzene layer is separated washed with water dried evaporated The residue is chromatographed on silica gel using 50% acetone in benzene the eluates are evaporated

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A solution of chloroacetyl chloride (657 mg, 0.0058 mol) in 30 ml of benzene is added dropwise to a stirring solution of 1,2,3,4,6,10b-hexahydropyrazino[2,1-a]isoindole-6-one (described in Example 8, 1.0 g, 0.0053 mol) and triethylamine (650 mg, 0.0064 mol) in 90 ml of benzene. The reaction is stirred at room temperature for 30 min and evaporated. A mixture of chloroform and water is added and the chloroform phase is collected, washed with water, dried and evaporated to afford 2-chloroacetyl-1,2,3,4,6,10b-hexahydropyrazino[2,1-a]isoindole-6-one, (1.2 g), nmr (CDCl3) δ 3.0-3.5(m), 4.2-4.8(m) and 7.3-7.9(m). evaporated A mixture of chloroform and water is added the chloroform phase is collected washed with water dried evaporated