Iodine → tert-Butyl (6-chloro-4-iodopyridin-3-yl)carbamate

Participants

Reaction Conditions

Reaction Steps

To a solution of TMEDA (1.45 g, 12.5 mmol) in dry Et2O (30 mL) was added dropwise n-BuLi (5.0 mL, 12.5 mmol) at −78° C. The mixture was stirred for 0.5 h at −78° C. A solution of (6-chloro-pyridin-3-yl)-carbamic acid tert-butyl ester (1.14 g, 5.0 mmol) in dry Et2O (10 mL) was added dropwise to the reaction mixture at −78° C. and the resultant mixture was continued to stir for 1 h at −78° C. A solution of I2 (1.52 g, 6.0 mmol) in dry Et2O (10 mL) was added dropwised at −78° C. The mixture was continued to stir for 1 h at this temperature. The reaction was quenched with saturated aqueous NH4Cl. The organic layer was separated and the aqueous phase was extracted with ethyl acetate (50 mL×3). The combined organic layers were dried over anhydrous Na2SO4 and evaporated under reduced pressure to give a residue, which was purified by column (petroleum ether/ethyl acetate=10/1) to obtain (6-chloro-4-iodo-pyridin-3-yl)-carbamic acid tert-butyl ester (1.75 g, 30%). 1H NMR (400 MHz, CDCl3) δ 8.95 (br s, 1H), 7.73 (s, 1H), 6.64 (br s, 1H), 1.54 (s, 1H).

Provenance & Evidence