6-chloro-3,3-dimethyl-1,4-dihydroquinoxalin-2-one

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

Procedure: Aqueous titanium trichloride (20%, 260 ml) is added dropwise over 10 min to a mixture of N-(5-chloro-2-nitrophenyl)-2-methylalanine methyl ester, (XI, EXAMPLE 11, 14.1 g), sodium acetate (240 g), methanol (504 ml) and water (156 ml). The mixture is stirred for 2.5 hr at 20°-25°. The material is partitioned between aqueous sodium bicarbonate and ethyl acetate, the phases are separated, the organic phase is dried over magnesium sulfate and concentrated under reduced pressure with heat to give the title compound, mp 166°-170°; IR (mineral oil) 3311, 2964, 2954, 2925, 1658, 1614, 1505, 1404 and 1355 cm-1 ; NMR (CDCl3) 8.67, 6.73, 6.6-6.7, 3.78 and 1.42 δ; MS (FAB) m/z 210, 195 and 167. The material is partitioned between aqueous sodium bicarbonate and ethyl acetate the phases are separated the organic phase is dried over magnesium sulfate concentrated under reduced pressure with heat

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

Procedure: Aqueous titanium trichloride (20%, 260 ml) is added dropwise over 10 min to a mixture of N-(5-chloro-2-nitrophenyl)-2-methylalanine methyl ester, (XI, EXAMPLE 11, 14.1 g), sodium acetate (240 g), methanol (504 ml) and water (156 ml). The mixture is stirred for 2.5 hr at 20°-25°. The material is partitioned between aqueous sodium bicarbonate and ethyl acetate, the phases are separated, the organic phase is dried over magnesium sulfate and concentrated under reduced pressure with heat to give the title compound, mp 166°-170°; IR (mineral oil) 3311, 2964, 2954, 2925, 1658, 1614, 1505, 1404 and 1355 cm-1 ; NMR (CDCl3) 8.67, 6.73, 6.6-6.7, 3.78 and 1.42 δ; MS (FAB) m/z 210, 195 and 167. The material is partitioned between aqueous sodium bicarbonate and ethyl acetate the phases are separated the organic phase is dried over magnesium sulfate concentrated under reduced pressure with heat

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

Procedure: Aqueous titanium trichloride (20%, 260 ml) is added dropwise over 10 min to a mixture of N-(5-chloro-2-nitrophenyl)-2-methylalanine methyl ester, (XI, EXAMPLE 11, 14.1 g), sodium acetate (240 g), methanol (504 ml) and water (156 ml). The mixture is stirred for 2.5 hr at 20°-25°. The material is partitioned between aqueous sodium bicarbonate and ethyl acetate, the phases are separated, the organic phase is dried over magnesium sulfate and concentrated under reduced pressure with heat to give the title compound, mp 166°-170°; IR (mineral oil) 3311, 2964, 2954, 2925, 1658, 1614, 1505, 1404 and 1355 cm-1 ; NMR (CDCl3) 8.67, 6.73, 6.6-6.7, 3.78 and 1.42 δ; MS (FAB) m/z 210, 195 and 167. The material is partitioned between aqueous sodium bicarbonate and ethyl acetate the phases are separated the organic phase is dried over magnesium sulfate concentrated under reduced pressure with heat