Reaction #1833228

Reaction equation

3,5-Difluorobenzene-1,2-diol

thiophosgene

NaOH

→

title compound

Yield 82.0%

4,6-Difluorobenzo[d][1,3]dioxole-2-thione

Yield 82.0%

Solvents

chloroform

Conditions

Workup

1. 1
   Otherthe volatiles were removed by rotary evaporation
2. 2
   Filtrationthe residual solid was collected by filtration
3. 3
   Washwashed with water
4. 4
   workup.DISSOLUTIONThe solid was dissolved in ethyl acetate (30 mL)
5. 5
   Washwashed with water (2×20 mL)
6. 6
   Washwashed with saturated NaCl (1×10 mL)
7. 7
   Dryingdried (Na2SO4)
8. 8
   Otherevaporated
9. 9
   OtherThe residue was purified by chromatography on silica with a 0-20% ethyl acetate-hexane gradient

Procedure

3,5-Difluorobenzene-1,2-diol (670 mg, 4.6 mmol) was stirred in dry chloroform (8 mL), treated with thiophosgene (580 mg, 5.0 mmol), cooled to 5-10° C., and treated dropwise with 10% NaOH solution (4.2 g, 11 mmol) over 45 min. After 30 min, the volatiles were removed by rotary evaporation and the residual solid was collected by filtration and washed with water. The solid was dissolved in ethyl acetate (30 mL), washed with water (2×20 mL), washed with saturated NaCl (1×10 mL), dried (Na2SO4), and evaporated. The residue was purified by chromatography on silica with a 0-20% ethyl acetate-hexane gradient to give the title compound (710 mg, 82%): 1H NMR (400 MHz, CDCl3) δ 6.95 (ddd, J=6.8, 2.3, 1.4 Hz, 1H), 6.89 (td, J=9.5, 2.3 Hz, 1H); 19F NMR (376 MHz, CDCl3) δ −109.99 (s), −127.93 (s); EIMS m/z 188.

Source