Water → N-Benzyl-5-methoxyisatin

HRID 447351Notes

Reaction equation

HRID 447351 reaction equation
[CH3:1][O:2][C:3]1[CH:4]=[C:5]2[C:9](=[CH:10][CH:11]=1)[NH:8][C:7](=[O:12])[C:6]2=[O:13].[H-].[Na+].[CH:16]1[CH:21]=[CH:20][C:19]([CH2:22]Br)=[CH:18][CH:17]=1.O>CN(C=O)C>[CH2:22]([N:8]1[C:9]2[C:5](=[CH:4][C:3]([O:2][CH3:1])=[CH:11][CH:10]=2)[C:6](=[O:13])[C:7]1=[O:12])[C:19]1[CH:20]=[CH:21][CH:16]=[CH:17][CH:18]=1

Participants

6

Reactant 4

HCID 962WaterHCID 7498Benzyl BromideHCID 24758Sodium hydrideHCID 383335-Methoxyisatin

Product 1

HCID 11357627N-Benzyl-5-methoxyisatinYield 81.5%

Reagents, catalysts & solvents 1

HCID 6228DimethylformamideSolvent

Procedure

A stirred solution of 5-methoxyisatin (5.0 g, 28 mmol) in dry DMF (40 mL) was cooled in an ice bath before addition of sodium hydride (60 wt % in mineral oil, 1.7 g, 42 mmol) slowly, the dark red solution turning quickly black. After stiffing for 20 min, BnBr (3.7 mL, 31 mmol) was added to the reaction mixture by syringe and the resulting mixture was stirred for 1 h. Water (150 mL) was added with stirring, and the resulting dark red precipitate collected by filtration and washed with water to give 1-benzyl-5-methoxyindoline-2,3-dione as a dark red solid (6.1 g, 81%). 1H NMR (400 MHz, CDCl3) δ 7.39-7.31 (m, 5H), 7.17 (s, 1H), 7.03 (d, J=8.1 Hz, 1H), 6.68 (d, J=8.6 Hz, 1H), 4.92 (s, 2H), 3.79 (s, 3H). MS ESI 268.1 [M+H]+, calcd for [C16H13NO3+H]+ 268.09.

Workup

  1. stirringwith stirring
  2. filtrationthe resulting dark red precipitate collected by filtration
  3. washwashed with water

Sources & evidence

ORD record
ord-f3d0e299887e42b6b9cfb412a2b7850e
Source dataset
uspto-grants-2013_07
Patent number
US08481533B2

Reaction notes

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