O-ALLYL-2,2,2-TRICHLOROACETIMIDATE

Reagent used for the protection of an alcohol as its allyl ether in the presence of base sensitive functionality.

O-allyl-2,2,2-trichloroacetimidate can be used to release allyl groups under mild conditions; used to prepare nitrogen-containing intermediates.

Sodium Hydride (0.5 g, 21 mmol) is slurried in anhydrous ether (20 mL) under a nitrogen blanket. Allyl alcohol (210 mmol) is introduced in ether (30 mL) dropwise with stirring to the slurry. After 20 min, the homogeneous solution is cooled to 0 °C and Trichloroacetonitrile (20 mL, 200 mmol) is added over 15 min. The mixture is allowed to warm to 20 °C over 60 min and then concentrated to a syrup. Pentane (20 mL) containing methanol (0.8 mL, 21 mmol) is added followed by vigorous shaking, filtration, and concentration of the filtrate and pentane washings (2 × 20 mL). The product imidate is obtained as a clear liquid (90-97%). No further purification is required. Alternatively, the imidate can be prepared by using sodium methoxide as a catalyst instead of sodium hydride. Other procedures for the preparation of allyl trichloroacetimidate have been reported.