Sodium hydride → (R)-tert-butyl 3-(6-chloropyrazin-2-yloxy)piperidine-1-carboxylate

Participants

Reaction Conditions

Reaction Steps

Sodium hydride (225.6 g, 5.64 mol) is dispersed into THF (3 L) and the temperature is lowered to 0-5° C. A solution of (R)-3-hydroxy-1-boc piperidine (891.6 g, 4.43 mol) in THF (3 L) is added over 1 h while maintaining the temperature between 0-5° C. The reaction is stirred for 1 h. 2,6-Dichloropyrazine (600 g, 4.03 mol) as a solution in THE (3 L) is added dropwise over 1.5 h maintaining the same temperature. The reaction is stirred for 2 h at 25-30° C., and then poured onto ice. The mixture is diluted with water and extracted with ethyl acetate. The extracts are dried over anhydrous sodium sulfate, filtered, and concentrated. The residual oil is triturated with 5% dichloromethane in hexane to give the product as a white solid. The solid is collected by filtration and dried, to give 1538 g crude material. The crude product is retriturated with 5% dichloromethane in hexanes to give a white solid in quantitative yield. ES/MS m/z 314.1 [M+H]+.

Provenance & Evidence