Diphosgene → 3-tert-Butyl-5-isocyanato-1-p-tolyl-1H-pyrazole

HRID 2069110Notes

Reaction equation

[C:1]([O-:4])(O)=O.[Na+].[C:6]([C:10]1[CH:14]=[C:13]([NH2:15])[N:12]([C:16]2[CH:21]=[CH:20][C:19]([CH3:22])=[CH:18][CH:17]=2)[N:11]=1)([CH3:9])([CH3:8])[CH3:7].ClC(OC(Cl)=O)(Cl)Cl>C(Cl)Cl>[C:6]([C:10]1[CH:14]=[C:13]([N:15]=[C:1]=[O:4])[N:12]([C:16]2[CH:17]=[CH:18][C:19]([CH3:22])=[CH:20][CH:21]=2)[N:11]=1)([CH3:9])([CH3:8])[CH3:7]

Participants

Conditions

Temperature: 0 °C

Procedure

A saturated aq. solution of NaHCO3 (14 mL) was added to a solution of 3-tert-butyl-1-p-tolyl-1H-pyrazol-5-amine (WO 2000043384) (206 mg, 0.900 mmol) in DCM (20 mL) and the mixture was cooled to 0° C. and stirred vigorously whilst trichloromethylchloroformate (325 μL, 2.70 mmol) was added in a single portion. The vigorous stirring was continued at 0° C. for a further 80 min. The organic layer was separated and dried and was then evaporated in vacuo to provide 3-tert-butyl-5-isocyanato-1-p-tolyl-1H-pyrazole, Intermediate B1 as orange oil. This material was pumped for 30 min under high vacuum and was then taken up into THF (6.0 mL) and kept under nitrogen at 0° C. and used directly in the next step.

Workup

additionwas added in a single portion
customThe organic layer was separated
customdried
customwas then evaporated in vacuo

Sources & evidence

ORD record: ord-26732cc99e044e44b4f9bb0d231b7acf
Source dataset: uspto-grants-2012_10
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US08299074B2

Reaction notes

Loading…