Diisopropylethylamine → ethyl 5-tert-butyl-1-(4-chloro-2-methylphenyl)-1H-pyrazole-4-carboxylate

HRID 1799431Notes

Reaction equation

C(N(C(C)C)C(C)C)C.Cl.[Cl:11][C:12]1[CH:17]=[CH:16][C:15]([NH:18][NH2:19])=[C:14]([CH3:20])[CH:13]=1.CN(/[CH:24]=[C:25](/[C:31](=O)[C:32]([CH3:35])([CH3:34])[CH3:33])\[C:26]([O:28][CH2:29][CH3:30])=[O:27])C>C(O)C>[C:32]([C:31]1[N:18]([C:15]2[CH:16]=[CH:17][C:12]([Cl:11])=[CH:13][C:14]=2[CH3:20])[N:19]=[CH:24][C:25]=1[C:26]([O:28][CH2:29][CH3:30])=[O:27])([CH3:35])([CH3:33])[CH3:34]

Participants

Conditions

Temperature: 90 °C

Procedure

N-Ethyldiisopropylamine (1.553 mL, 8.97 mmol) was added to (4-chloro-2-methylphenyl)hydrazine hydrochloride (1.733 g, 8.97 mmol) and (Z)-ethyl 2-((dimethylamino)methylene)-4,4-dimethyl-3-oxopentanoate (Intermediate #83) (2.04 g, 8.97 mmol) in ethanol (30 mL). The resulting solution was stirred at 90° C. for 2 hours. The reaction mixture was evaporated to dryness and redissolved in DCM (50 mL), and washed sequentially with water (2×10 mL). The organic layer was dried over MgSO4, filtered and evaporated to afford crude product. The crude product was purified by flash silica chromatography, elution gradient 0 to 10% EtOAc in isohexane. Pure fractions were evaporated to dryness to afford ethyl 5-tert-butyl-1-(4-chloro-2-methylphenyl)-1H-pyrazole-4-carboxylate (0.891 g, 30.9%) as a orange oil.

Workup

customThe reaction mixture was evaporated to dryness
dissolutionredissolved in DCM (50 mL)
washwashed sequentially with water (2×10 mL)
dry with materialThe organic layer was dried over MgSO4
filtrationfiltered
customevaporated
customto afford crude product
customThe crude product was purified by flash silica chromatography, elution gradient 0 to 10% EtOAc in isohexane
customPure fractions were evaporated to dryness

Sources & evidence

ORD record: ord-678e3458ace94247a9475079b4daa105
Source dataset: uspto-grants-2013_01
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US08344016B2

Reaction notes

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