Reacción #1833240

Ecuación de reacción

5-Bromo-3-fluorobenzene-1,2-diol

thiophosgene

Sodium hydroxide

→

title compound

Rendimiento 62.1%

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

Rendimiento 62.1%

Disolventes

chloroform

ethyl acetate

Condiciones de reacción

Tratamiento posterior

1. 1
   workup.WAITAfter 1 h
2. 2
   Otrothe chloroform was removed under vacuum
3. 3
   workup.ADDITIONthe pH was adjusted to 2 by addition of 6 M HCl
4. 4
   OtroThe solid that was formed
5. 5
   Lavadowashed with saturated NaCl (30 mL)
6. 6
   Secadodried (Na2SO4)
7. 7
   Otroevaporated
8. 8
   OtroThe material was purified by flash chromatography

Procedimiento

5-Bromo-3-fluorobenzene-1,2-diol (2.0 g, 9.7 mmol, prepared according to Lu, Hejun; Tang, Peng Cho; Chen, Yiqian; Wang, Shenglan; Wang, Hua; Zhang, Lei; Li, Jun, WO 2011140936 A1) was dissolved in chloroform (25 mL), treated with thiophosgene (1.2 g, 11 mmol) and cooled to 0-5° C. Sodium hydroxide (10% aqueous, 8.9 g, 22 mmol) was added dropwise with vigorous stirring over 30 min. After 1 h, the chloroform was removed under vacuum and the pH was adjusted to 2 by addition of 6 M HCl. The solid that was formed was taken up in ethyl acetate (120 mL), washed with saturated NaCl (30 mL), dried (Na2SO4) and evaporated. The material was purified by flash chromatography using a 0-30% ethyl acetate-hexane gradient to give the title compound as a tan solid (1.5 g, 62%): mp 41-42° C.; 1H NMR (400 MHz, CDCl3) δ 7.35-7.30 (m, 1H), 7.29 (d, J=1.6 Hz, 1H); 19F NMR (376 MHz, CDCl3) δ −128.93; EIMS m/z 248/250.

Fuente