反应详情

A dispersion of sodium hydride (50% oil; 0.16 g) in dry N,N-dimethylformamide (3 ml) was cooled to 0° C., and a solution of 3-[6-chloro-2(3H)-benzothiazolon-5-yl]-5-(1,1-dimethylethyl) -1,3,4-oxadiazol-2(3H)-one (1.00 g) in dry N,N-dimethylformamide (3 ml) was dropwise added thereto at the same temperature, followed by stirring at the same temperature for 30 minutes. Upon addition of propargyl bromide (0.44 g), the resultant mixture was heated to 50° C. and stirred for 5 hours. The reaction mixture was allowed to cool, combined with water and extracted with ethyl acetate. The extract was washed with water, dried and concentrated. The residue was purified by silica gel thin layer chromatography with a mixture of ether and hexane (1 : 1) as an eluent to give 3-[6-chloro-3-(2-propenyl)-2(3H)-benzothiazolon-5-yl] -5-(1,1-dimethylethyl)-1,3,4-oxadiazol -2(3H)-one (0.28 g). nD25.5 1.5703.

1. stirringstirred for 5 hours
2. temperatureto cool
3. extractionextracted with ethyl acetate
4. washThe extract was washed with water
5. customdried
6. concentrationconcentrated
7. customThe residue was purified by silica gel thin layer chromatography with a mixture of ether and hexane (1 : 1) as an eluent