Dimethylformamide → 3-chloro-2-(3-(trifluoromethyl)-1H-pyrazol-1-yl)pyridine

HRID 924612Notes

Reaction equation

[F:1][C:2]([F:9])([F:8])[C:3]1[CH:7]=[CH:6][NH:5][N:4]=1.Cl[C:11]1[C:16]([Cl:17])=[CH:15][CH:14]=[CH:13][N:12]=1.CN(C)C=O.C(=O)([O-])[O-].[K+].[K+]>O>[Cl:17][C:16]1[C:11]([N:5]2[CH:6]=[CH:7][C:3]([C:2]([F:9])([F:8])[F:1])=[N:4]2)=[N:12][CH:13]=[CH:14][CH:15]=1

Participants

Conditions

Temperature: 120 °C

Procedure

1.72 kg (10.75 mol) of the raw 3-trifluoromethylpyrazole obtained in step a), 1.75 kg (11.83 mol) of 2,3-dichloropyridine and 4.73 kg of dimethyl formamide were charged to a reaction vessel. 2.97 kg (21.50 mol) of potassium carbonate were added, the mixture was heated to 120° C. with stirring and kept at 120-125° C. for further 3 h. The reaction mixtures was cooled to 25° C. and poured into 20 l of water. The thus obtained mixture was extracted twice with 5 L of tert.-butylmethyl ether. The combined organic phases were washed with 4 l of water and then evaporated to dryness. Toluene was added and the mixture was again evaporated to dryness. Thereby, the 2.7 kg of the title compound was obtained (purity >75% as determined by GC; yield 81.5%). The product can be purified by distillation.

Workup

customThe reaction mixtures
temperaturewas cooled to 25° C.
extractionThe thus obtained mixture was extracted twice with 5 L of tert.-butylmethyl ether
washThe combined organic phases were washed with 4 l of water
customevaporated to dryness
additionToluene was added
customthe mixture was again evaporated to dryness

Sources & evidence

ORD record: ord-81cdf960130f45e392b01cabf392f335
Source dataset: uspto-grants-2016_03
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US09282741B2

Reaction notes

Loading…