(Dimethyl sulfide)trihydroboron → 4-methyl-7-methoxy-3,4-dihydro-2H-[1,4]benzoxazine

Participants

Reaction Steps

7-Methoxy-4-methyl-4H-benzo[1,4]oxazin-3-one (13.07 g, 0.68 mol) was added to 100 mL dry THF, and the reaction mixture was refluxed under nitrogen. Borane-dimethyl sulfide (13.6 mL, 0.136 mol) was added dropwise over one hour, and the reaction mixture was allowed to reflux for two hours. The reaction mixture was cooled and then quenched by addition of 50 mL of 10% aqueous HCl. Precipitate was removed by filtration, and the liquid was concentrated under reduced pressure to give 11.17 g of 7-Methoxy-4-methyl-3,4-dihydro-2H-benzo[1,4]oxazine. (M+H)=180.

Provenance & Evidence