Di-tert-butyl dicarbonate → tert-Butyl 5-amino-3-methyl-1H-indazole-1-carboxylate

HRID 2070872Notes

Reaction equation

[CH3:1][C:2]1[C:10]2[C:5](=[CH:6][CH:7]=[C:8]([N+:11]([O-])=O)[CH:9]=2)[N:4]([C:14]([O:16][C:17]([CH3:20])([CH3:19])[CH3:18])=[O:15])[N:3]=1.CC1C2C(=CC=C([N+]([O-])=O)C=2)NN=1.C(OC(OC(C)(C)C)=O)(OC(C)(C)C)=O>C(O)C>[NH2:11][C:8]1[CH:9]=[C:10]2[C:5](=[CH:6][CH:7]=1)[N:4]([C:14]([O:16][C:17]([CH3:19])([CH3:18])[CH3:20])=[O:15])[N:3]=[C:2]2[CH3:1]

Participants

Conditions

Temperature: 50 °C

Procedure

tert-Butyl 3-methyl-5-nitro-1H-indazole-1-carboxylate. To a solution of 3-methyl-5-nitro-1H-indazole (0.95 g, 5.36 mmol) in ethanol (12 mL) was added di-tert-butyl dicarbonate (1.755 g, 8.04 mmol). The reaction was stirred at 50° C. for 5 h. The reaction mixture was cooled down to room temperature and the solvent was removed under reduced pressure. The crude was diluted with ethyl acetate (150 mL), washed with saturated sodium bicarbonate (100 mL), and brine (100 mL). The organic layer was dried over magnesium sulfate, filtered and concentrated down to give the title compound as an off-white solid, which was used in the next step without further purification. MS (ESI) m/z 278.4 [M+1]+.

Workup

temperatureThe reaction mixture was cooled down to room temperature
customthe solvent was removed under reduced pressure
additionThe crude was diluted with ethyl acetate (150 mL)
washwashed with saturated sodium bicarbonate (100 mL), and brine (100 mL)
dry with materialThe organic layer was dried over magnesium sulfate
filtrationfiltered
concentrationconcentrated down

Sources & evidence

ORD record: ord-43b5b050ac9d400aaf5dc72a40b3f220
Source dataset: uspto-grants-2012_10
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US08299056B2

Reaction notes

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