Hydrogen Peroxide → HCID 9945682, compound

Participants

Reaction Steps

A solution of 2-(2-chlorobenzyl)-5-chloro-7-allylbenzoxazole (40 g, 0.126 mol) in THF (63 ml) was added to a solution at 0° C. of di-iso-amylborane prepared in THF from 10.8 g of borane-tetrahydrofuran complex and 19.5 g of 2-methyl-2-butene. The reaction mixture was allowed to warm to room temperature. After 16 hours, the reaction mixture was cooled to 5° C. and 3 N sodium hydroxide (50 ml) was added slowly followed by the slow addition of 30% hydrogen peroxide (50 ml). After 3 hours, the reaction mixture was diluted with dichloromethane (300 ml) and water (300 ml). The layers were separated and the aqueous solution was extracted with dichloromethane (2×150 ml). The dichloromethane extracts were combined and washed with water (3×200 ml) and evaporated under reduced pressure to give an oil. The crude product was purified by flash chromatography (silica gel; 300 g). Elution with 2 l of 1:1 hexane/dichloro-methane gave starting material (3.5 g). Elution with dichloromethane (5 l) afforded 32 g of the title compound, mp 87-89° C. (from toluene).

Provenance & Evidence