Reaction #64595

Reaction equation

2-amino-4-methoxycarbonylphenol

O-ethylxanthic acid potassium salt

HCl

→

5-methoxycarbonylbenzoxazol-2-thione

Yield 95.0%

Solvents

pyridine

Conditions

Workup

1. 1
   OtherIn a round bottom flask equipped with a mechanical stirrer
2. 2
   Temperaturereflux condenser
3. 3
   Otherdrying tube
4. 4
   Temperatureheated
5. 5
   Temperatureat reflux for 2 hours
6. 6
   OtherThe product was collected as a solid
7. 7
   Washwashed thoroughly with water
8. 8
   Otherdried

Procedure

In a round bottom flask equipped with a mechanical stirrer, reflux condenser and drying tube were placed 2-amino-4-methoxycarbonylphenol (8,3 g, 0.05 mole), O-ethylxanthic acid potassium salt (8.8 g, 0.055 mole) and pyridine (125 mL). The mixture was stirred and heated at reflux for 2 hours and cooled to room temperature. The mixture was poured into ice and concentrated HCl (50 mL). The product was collected as a solid and washed thoroughly with water. The material was air dried to give 9.9 g (95%) of the 5-methoxycarbonylbenzoxazol-2-thione as a white powder, m.p. 218°-221° C.

Source