Stannous chloride dihydrate → 3-(4-bromo-2-isopropyl-2H-pyrazol-3-yl)-4-methoxy-phenylamine

HRID 407443Notes

Reaction equation

[Br:1][C:2]1[CH:3]=[N:4][N:5]([CH:18]([CH3:20])[CH3:19])[C:6]=1[C:7]1[CH:12]=[C:11]([N+:13]([O-])=O)[CH:10]=[CH:9][C:8]=1[O:16][CH3:17].O.O.Cl[Sn]Cl>C(O)C>[Br:1][C:2]1[CH:3]=[N:4][N:5]([CH:18]([CH3:20])[CH3:19])[C:6]=1[C:7]1[CH:12]=[C:11]([NH2:13])[CH:10]=[CH:9][C:8]=1[O:16][CH3:17]

Participants

Conditions

Temperature: 55 °C

Procedure

To a solution of 4-bromo-1-isopropyl-5-(2-methoxy-5-nitro-phenyl)-1H-pyrazole (0.50 g, 1.47 mmol) in ethanol (5.0 mL), was added SnCl2.2H2O (1.3 g, 5.88 mmol) and the mixture was heated at 55° C. overnight. The ethanol was evaporated and the residue was taken up in ethyl acetate (50 mL) and washed with 10% NaOH (10 mL). The organic layer was dried over MgSO4 and evaporated to yield a light yellow solid. The crude material was purified via Biotage silica chromatography (hexane/EtOAc, 3/1) to yield a pale yellow solid of 3-(4-bromo-2-isopropyl-2H-pyrazol-3-yl)-4-methoxy-phenylamine (0.38 g, 85%). LCMS m/z (%)=311 M+H+, (79Br, 100), (81Br, 96.5), 1H NMR (400 MHz, CDCl3) δ: 7.47 (s, 1H), 6.78 (d, J=8.08 Hz, 1H), 6.72 (dd, J1=8.01 Hz, J2=2.78 Hz, 1H), 6.54 (d, J=2.78 Hz, 1H), 4.14 (m, 1H), 3.63 (s, 3H), 1.4 (d, J=6.57 Hz, 3H), 1.23 (d, J=6.57 Hz, 3H).

Workup

customThe ethanol was evaporated
washwashed with 10% NaOH (10 mL)
dry with materialThe organic layer was dried over MgSO4
customevaporated
customto yield a light yellow solid
customThe crude material was purified via Biotage silica chromatography (hexane/EtOAc, 3/1)

Sources & evidence

ORD record: ord-264d318606d8443daccb9fdeed5279c8
Source dataset: uspto-grants-2014_06
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US08754238B2

Reaction notes

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