Triethylamine → (2-Chloro-3-nitro-6-trifluoromethyl-pyridin-4-yl)-carbamic acid ethyl ester

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Reaction Steps

2-Chloro-3-nitro-6-trifluoromethyl-pyridin-4-ylamine (2.2 g, 9.1 mmol) was stirred in 2-MeTHF (20 ml) and triethylamine added (1.52 ml, 10.9 mmol). The solution was cooled in an ice bath to ˜5° C. before the dropwise addition of ethyl chloroformate (1.04 ml, 10.9 mmol), the solution warmed to ambient temperature and left to stir under a nitrogen atmosphere for 16 h. 20 ml EtOAc and 10 ml H20 were added and the phases separated, washed with a additional 2×10 ml sat'd brine solution. The organic extract was dried over MgSO4, concentrated in vacuo and preabsorbed onto a silica column. Elution with Hept:EtOAc, 9:1 gave 2.1 g of the title compound as a white solid.

Provenance & Evidence