5-Nitroindole → 3-(2-Methoxy-4-methoxycarboxybenzyl)-5-nitroindole

Participants

Reaction Conditions

Reaction Steps

Silver(I) oxide (7.15 g) was added to a solution of 5-nitroindole (5 g) and methyl 4-bromomethyl-3-methoxybenzoate (prepared as described in step (a) of Example 1) (7.99 g) in dioxane (30 ml), under a nitrogen atmosphere. The mixture was stirred at 60° C. for 20 hours, dioxane removed by evaporation, and ethyl acetate (50 ml) added to the residue. The resulting suspension was separated by filtration through diatomaceous earth. The filtrate was evaporated to give a dark viscous oil, which was purified by flash chromatography on silica gel (600 ml), eluting with 3:7 v/v ethyl acetate:hexane. The viscous yellow oil obtained was crystallized from a mixture of methylene chloride and hexane to give methyl 3-methoxy-4-(5-nitroindol-3-ylmethyl)benzoate (F) (4.6 g, 45%) as yellow needles; mp 153°-155° C.; NMR: 3.83(s, 3H, COOCH3), 3.93(s, 3H, OCH3), 4.12(s, 2H, CH2Ar), 7.25(d, 1H), 7.43(d, 1H), 7.49(m, 3H), 7.95(dd, 1H, H6 -indole), 8.47(d, 1H, H4 -indole), 11.65(broad s, 1H, H1 -indole).

Provenance & Evidence