2,4-Dimethyl-5-nitroaniline → 5-methyl-6-nitro-1H-indazole

HRID 386654Notes

Reaction equation

[CH3:1][C:2]1[CH:8]=[C:7]([CH3:9])[C:6]([N+:10]([O-:12])=[O:11])=[CH:5][C:3]=1[NH2:4].[N:13]([O-])=O.[Na+]>C(O)(=O)C.O>[CH3:9][C:7]1[CH:8]=[C:2]2[C:3](=[CH:5][C:6]=1[N+:10]([O-:12])=[O:11])[NH:4][N:13]=[CH:1]2

Participants

Conditions

Temperature: 0 °C

Procedure

2,4-Dimethyl-5-nitroaniline (1.662 g, 10.00 mmol) was dissolved in glacial acetic acid (100 ml) and the mixture was cooled to 0° C. A solution of sodium nitrite (1 eq, 690 mg) in water (2 ml) was added while maintaining a temperature below 25° C. Stirring was continued for three hours and the mixture was filtered. The filtrate was allowed to stand for three days at room temperature, then was concentrate under reduced pressure. The residue was diluted with water and the resulting mixture was stirred vigorously. The solid product was collected by filtration, washed thoroughly with cold water, and dried. The product was purified by flash chromatography (99:1 dichloromethane/methanol) to give 1.030 g (58.1%) of 5-methyl-6-nitro-1H-indazole as a solid.

Workup

temperaturewhile maintaining a temperature below 25° C
filtrationthe mixture was filtered
waitto stand for three days at room temperature
concentrationwas concentrate under reduced pressure
additionThe residue was diluted with water
stirringthe resulting mixture was stirred vigorously
filtrationThe solid product was collected by filtration
washwashed thoroughly with cold water
customdried
customThe product was purified by flash chromatography (99:1 dichloromethane/methanol)

Sources & evidence

ORD record: ord-0325add8818b44d78e5cc4465481c574
Source dataset: uspto-grants-2013_02
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US08372865B2

Reaction notes

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