反应详情

3-(5-Amino-2-chlorophenyl)-5-(1,1-dimethyl-ethyl) -1,3,4-oxadiazol-2(3H)-one (38.28 g) was dissolved in 95% acetic acid (138.20 g), and ammonium thiocyanate (27.64 g) was added thereto, followed by stirring at room temperature for 3 hours. To the resultant mixture, a solution of bromine (27.64 g) in acetic acid (41.46 g) was added, followed by stirring at room temperature for 12 hours. The reaction mixture was combined with hot water (274.7 ml), heated to 100° C. and filtered while hot. The filtrate was neutralized with sodium carbonate and extracted with ethyl acetate. The extract was washed with water, dried and distilled under reduced pressure to give 3-(2-amino-6-chloro-benzothiazol -5-yl)-5-(1,1-dimethylethyl)-1,3,4-oxadiazol-2(3H)-one (39.06 g) as a resinous substance.

1. stirringby stirring at room temperature for 12 hours
2. temperatureheated to 100° C.
3. filtrationfiltered while hot
4. extractionextracted with ethyl acetate
5. washThe extract was washed with water
6. customdried
7. distillationdistilled under reduced pressure