反应详情

In a 500 ml reactor fitted with mechanical stirring, thermometer, addition funnel, reflux condenser and nitrogen inlet, [2,1,3]-benzoxadiazole-5-carboxylic acid (28 g) was suspended in toluene (245 ml). To this suspension was added thionyl chloride (39.4 g) and DMF (0.35 ml). The resulting mixture was heated to reflux and maintained for 3 hours. A short pass column was installed and toluene was distilled (atmospheric pressure, 124 ml) off to remove excess reagent. After cooling the remaining toluene was distilled off, which resulted in a thick oil. This oil was distilled (90° C., 2 mm Hg) to remove impurities and the product crystallized on standing (79.8% yield), mp: 55-58° C.

1. customIn a 500 ml reactor fitted with mechanical stirring
2. additionthermometer, addition funnel
3. temperaturereflux condenser and nitrogen inlet
4. temperatureThe resulting mixture was heated
5. temperatureto reflux
6. temperaturemaintained for 3 hours
7. distillationtoluene was distilled (atmospheric pressure, 124 ml) off
8. customto remove excess reagent
9. temperatureAfter cooling the remaining toluene
10. distillationwas distilled off
11. customwhich resulted in a thick oil
12. distillationThis oil was distilled (90° C., 2 mm Hg)
13. customto remove impurities
14. customthe product crystallized