Dimethylformamide → 1-Methyl-6-nitro-1H-indole

HRID 2268162Notes

Reaction equation

[N+:1]([C:4]1[CH:12]=[C:11]2[C:7]([CH:8]=[CH:9][NH:10]2)=[CH:6][CH:5]=1)([O-:3])=[O:2].[C:13](=O)([O-])[O-].[K+].[K+].CN(C)C=O.C(=O)(OC)OC>CCCCCCC.O.C(OCC)(=O)C>[CH3:13][N:10]1[C:11]2[C:7](=[CH:6][CH:5]=[C:4]([N+:1]([O-:3])=[O:2])[CH:12]=2)[CH:8]=[CH:9]1

Participants

Conditions

Temperature: 126 °C

Procedure

A 1L, three-necked flask equipped with a thermocouple, condenser, and addition funnel was charged with 6-nitroindole (60.0 g, 0.37 mol), potassium carbonate (12.0 g, 87 mmol), N,N-dimethylformamide (240 mL) and dimethyl carbonate (66 mL, 0.784 mol) and the resulting stirred mixture was heated to 126±3° C. The progress of the reaction was monitored by HPLC or TLC (solvent system: 30% ethyl acetate in heptane). After 1 h at this temperature, residual 6-nitroindole could not be detected. Then, the reaction mixture was cooled to 10±5° C. and slowly diluted with water (480 mL). As the water was added, a yellow precipitate formed. The resulting mixture was stirred at room temperature for 2 h, then the solid was recovered by filtration, washed with water (250 mL) and dried under high vacuum at 60-65° C. for 24 h to give 62.6 g of 1-methyl6-nitroindole (96.1% yield) as a yellow solid.

Workup

temperatureThen, the reaction mixture was cooled to 10±5° C.
customa yellow precipitate formed
stirringThe resulting mixture was stirred at room temperature for 2 h
filtrationthe solid was recovered by filtration
washwashed with water (250 mL)
customdried under high vacuum at 60-65° C. for 24 h

Sources & evidence

ORD record: ord-7e05af9ae5674763be1395172607edd1
Source dataset: uspto-grants-2001_12
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US06326501B1

Reaction notes

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