tert-Butanol → [6-[3-(Trifluoromethyl)phenyl]-4-pyridazinyl]carbamic acid, 1,1-dimethylethyl ester

Participants

Reaction Steps

6-[3-(trifluoromethyl)phenyl]-4-pyridazinecarboxylic acid (30 g, 0.112 mole, Compound No. 2), diphenylphosphorylazide (33.9 g, 0.123 mole) and triethylamine (17 g, 0.168 mole) were refluxed under N2 in t-butanol (250 mL) for 4 h. The mixture was then partitioned between ethyl acetate and water. The organic layer was dried (MgSO4), filtered through silica gel and evaporated in vacuo to give a crude solid which can be utilized as is in the next step or chromatographed on a Prep-500 to give [6-[3-(trifluoromethyl)phenyl]-4-pyridazinyl]carbamic acid, 1,1-dimethylethyl ester (Compound No. 3) as a white solid which was recrystallized from cyclohexane/ethyl acetate.

Provenance & Evidence