Reaction #2122515

Reaction equation

Chlorosulfonic acid

2-methylbenzoxazole

→

Compound 8

Yield 59.9%

2-methylbenzoxazole-6-sulfonyl chloride

Yield 59.9%

Solvents

Conditions

Workup

1. 1
   Otherof 15 min
2. 2
   TemperatureAfter cooling
3. 3
   workup.ADDITIONmix
4. 4
   OtherThe white solid that separated
5. 5
   Filtrationwas collected by filtration
6. 6
   Washwashed with water until washings
7. 7
   Otherdried

Procedure

Chlorosulfonic acid (12.5 ml, 187.8 mmol) was cooled in an ice bath and 2-methylbenzoxazole (5.0 g, 37.5 mmol) was carefully added drop wise over a period of 15 min. The combined mixture was heated at 115-120° C. for 16 hours. After cooling, the mixture was added very slowly to ca. 100 ml ice/water mix. The white solid that separated was collected by filtration, washed with water until washings were neutral and dried to yield 5.2 g (59%) of Compound 8, whose structure is given below:

Source