Potassium Carbonate → Ethyl 1-(3-methyl-2-pyridyl)-4-formyl-pyrazole-3-carboxylate

HRID 1517604Notes

Reaction equation

Cl[C:2]1[C:3]([N:8]2[CH:12]=[C:11]([CH:13]=[O:14])[C:10]([C:15]([O:17][CH2:18][CH3:19])=[O:16])=[N:9]2)=[N:4][CH:5]=[CH:6][CH:7]=1.[CH3:20]B1OB(C)OB(C)O1.C(=O)([O-])[O-].[K+].[K+]>O1CCOCC1.O.C1(P(C2C=CC=CC=2)C2C=CC=CC=2)C=CC=CC=1.[Pd]>[CH3:20][C:2]1[C:3]([N:8]2[CH:12]=[C:11]([CH:13]=[O:14])[C:10]([C:15]([O:17][CH2:18][CH3:19])=[O:16])=[N:9]2)=[N:4][CH:5]=[CH:6][CH:7]=1

Participants

Conditions

Temperature: 110 °C

Procedure

A mixture of ethyl 1-(3-chloro-2-pyridyl)-4-formyl-pyrazole-3-carboxylate (1.0 g, 3.5 mmol), trimethylboroxine (0.44 g, 3.50 mmol) and potassium carbonate (1.4 g, 10.1 mmol) in dioxane (18 mL) and water (2 mL) is degassed with nitrogen gas for 10 min and then palladium triphenylphosphine (0.40 g, 0.3 mmol) is added and stirred at 110° C. for 16 h. After completion, the reaction mixture is partitioned between dichloromethane (50 mL) and water (25 mL). The aqueous layer is extracted with dichloromethane (2×25 mL) and the combined organic extracts are dried over sodium sulfate and concentrated in vacuo. The crude mixture is purified by column chromatography over silica gel eluting with hexane/ethyl acetate (70:30) to yield 0.12 g (13%) of the title compound. MS (m/z): 260 (M+1).

Workup

customis degassed with nitrogen gas for 10 min
customAfter completion, the reaction mixture is partitioned between dichloromethane (50 mL) and water (25 mL)
extractionThe aqueous layer is extracted with dichloromethane (2×25 mL)
dry with materialthe combined organic extracts are dried over sodium sulfate
concentrationconcentrated in vacuo
customThe crude mixture is purified by column chromatography over silica gel eluting with hexane/ethyl acetate (70:30)

Sources & evidence

ORD record: ord-3ff59e88883643b6b1ff9f9ecf12d4d3
Source dataset: uspto-grants-2012_07
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US08232289B2

Reaction notes

Loading…