Ammonium Chloride → 3-[2(R)-isopropyl-3(p-tert-butyl-phenyl)-propionyl]-4(R)-benzyl-oxazolidin-2-one

Participants

Reaction Conditions

Reaction Steps

A solution of 4(R)-benzyl-3-isovaleroyl-oxazolidin-2-one (13.2 g) in tetrahydrofuran (20 ml) is added dropwise under an inert atmosphere, with stirring, at -70° C. to a 1M lithium hexamethyldisilazide solution in tetrahydrofuran (31 ml) which has been diluted with tetrahydrofuran (30 ml), and the reaction mixture is stirred at -70° C. for 1 hour. A solution of p-tert-butyl-benzyl bromide (9.6 g) in tetrahydrofuran (20 ml) is then added dropwise and the mixture is stirred for a further one hour at -25° C. and for 4 hours at 0° C. 6 ml of a saturated ammonium chloride solution are added to the reaction mixture which is then freed of tetrahydrofuran by concentration under reduced pressure and extracted with diethyl ether. The title compound is obtained from the residue of the extract by purification by means of FC (700 g of silica gel, eluant dichloromethane/hexane 1:1): Rf (dichloromethane/hexane 1:1)=0.30; m.p. 123.5°-124° C.

Provenance & Evidence