5-Nitroindole → 3-(2-Methoxy-4-methoxycarboxybenzyl)-5-nitroindole
Reaction equation
[N+:1]([C:4]1[CH:5]=[C:6]2[C:10](=[CH:11][CH:12]=1)[NH:9][CH:8]=[CH:7]2)([O-:3])=[O:2].Br[CH2:14][C:15]1[CH:24]=[CH:23][C:18]([C:19]([O:21][CH3:22])=[O:20])=[CH:17][C:16]=1[O:25][CH3:26]>O1CCOCC1.[Ag-]=O>[CH3:26][O:25][C:16]1[CH:17]=[C:18]([CH:23]=[CH:24][C:15]=1[CH2:14][C:7]1[C:6]2[C:10](=[CH:11][CH:12]=[C:4]([N+:1]([O-:3])=[O:2])[CH:5]=2)[NH:9][CH:8]=1)[C:19]([O:21][CH3:22])=[O:20]Participants
Conditions
- Temperature
- 60 °C
Procedure
Silver (I) oxide (7.15 g.) was added to a solution of 5-nitroindole (5 g.) and methyl 4-bromomethyl-3-methoxybenzoate (B) (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 dichloromethane and hexane to give methyl 3-methoxy-4-(5-nitroindol-3-ylmethyl)benzoate (C) (4.6 g., 45%) as yellow needles, m.p. 153°-155° C. NMR: 3.83(s,3H, COOCH3), 3.93(s,3H, OCH3), 4.12(s,2H, CH2.Ar), 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).
Workup
- customdioxane removed by evaporation and ethyl acetate (50 ml.)
- additionadded to the residue
- customThe resulting suspension was separated by filtration through diatomaceous earth
- customThe filtrate was evaporated
- customto give a dark viscous oil, which
- customwas purified by flash chromatography on silica gel (600 ml.)
- washeluting with 3:7 v/v ethyl acetate
- customThe viscous yellow oil obtained
- customwas crystallized from a mixture of dichloromethane and hexane
Sources & evidence
- ORD record
- ord-29458551a96d473ca106499ecf378d29
- Source dataset
- uspto-grants-1995_02
- Patent number
- US05391758
Reaction notes
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