Water → Tert-butyl 4-(3-amino-4-nitrophenyl)piperazine-1-carboxylate

HRID 1465815Notes

Reaction equation

Cl[C:2]1[CH:3]=[CH:4][C:5]([N+:9]([O-:11])=[O:10])=[C:6]([CH:8]=1)[NH2:7].[C:12]([O:16][C:17]([N:19]1[CH2:24][CH2:23][NH:22][CH2:21][CH2:20]1)=[O:18])([CH3:15])([CH3:14])[CH3:13].C(=O)([O-])[O-].[K+].[K+].O>CN(C)C(=O)C>[C:12]([O:16][C:17]([N:19]1[CH2:24][CH2:23][N:22]([C:2]2[CH:3]=[CH:4][C:5]([N+:9]([O-:11])=[O:10])=[C:6]([NH2:7])[CH:8]=2)[CH2:21][CH2:20]1)=[O:18])([CH3:15])([CH3:13])[CH3:14]

Participants

Conditions

Temperature: 120 °C

Procedure

A mixture of 5-chloro-2-nitroaniline (5.0 g, 29 mmol), piperazine-1-carboxylic acid tert-butyl ester (17 g, 9.1 mmol) and anhydrous potassium carbonate (4.4 g, 32 mmol) in N,N-dimethylacetamide (20 ml) was stirred at 120° C. under nitrogen for 2 days. Sample NMR analysis showed almost complete conversion of the starting material. The resultant mixture was then cooled to room temperature, poured into cold water (50 mL) and stirred vigorously for 2 hours. The resulting yellow precipitate was collected by filtration, washed well with water then dried on the filter funnel. The resulting yellow brown solid was slurried in diethyl ether, filtered, washed with additional diethylether, dried to afford 4-(3-Amino-4-nitro-phenyl)-piperazine-1-carboxylic acid tert-butyl ester (8.0 g, 85.7%) as a yellow powder, and used in the next step without further purification.

Workup

stirringstirred vigorously for 2 hours
filtrationThe resulting yellow precipitate was collected by filtration
washwashed well with water
customthen dried on the filter funnel
filtrationfiltered
washwashed with additional diethylether
customdried

Sources & evidence

ORD record: ord-8d99eb10159d480f9c59e4eaed8a8bff
Source dataset: uspto-grants-2015_04
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US08999993B2

Reaction notes

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