Trifluoromethanesulfonic anhydride → 5-Methyl-3-(3-allyl-4-trifluoromethylsulphonyloxyphenyl)-1,2,4-oxadiazole

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Reaction Steps

Triflic anhydride (1.4 ml) was added dropwise to a stirred solution of 5-methyl-3-(3-allyl-4-hydroxyphenyl)1,2,4-oxadiazole (1.2 g) in pyridine (10 ml) cooled in an ice-bath. The mixture was stirred for 45 minutes. The mixture was diluted with 1M aqueous hydrochloric acid (200 ml) and extracted with ethyl acetate (200 ml). The organic extract was washed with 1M aqueous hydrochloric acid, aqueous sodium bicarbonate solution, and brine, then dried (MgSO4), and evaporated to give 5-methyl-3-(3-allyl-4-trifluoromethylsulphonyloxyphenyl)-1,2,4-oxadiazole (1.37 g) as a solid, NMR: 8.1(2H,m), 7.6(1H,d), 6.1-5.9(1H,m), 5.3-5.1(2H,m), 3.55(2H,d) and 2.7(3H,s); m/z 351 (M+H).

Provenance & Evidence