ChemicalBook CAS DataBase List 2,3-Difluoronitrobenzene

2,3-Difluoronitrobenzene synthesis

4synthesis methods

Product Name:2,3-Difluoronitrobenzene
CAS Number:6921-22-8
Molecular formula:C6H3F2NO2
Molecular Weight:159.09

To a stirred solution of hydroxy peroxide (30 % in H2O, 35 mL, 356 mmol) under N2 at 0℃, a solution of trifluoroacetic anhydride (56 mL, 407 mmol) in 115 mL dichloromethane was added dropwise over 2 h. After the addition was complete, a solution of 2,3- difluorobenzenamine (5 g, 39 mmol) in 115 mL dichloromethane was added dropwise at 0℃. After the addition was complete, the reaction mixture was gradually warmed to room temperature and stirred overnight. The mixture was extracted by dichloromethane and dried over anhydrous Na2SO4. The mixture was filtered and concentrated under reduced pressure. The residue was purified by flash column with 0-15 % EtOAc in hexane to yield 3.5 g of 2,3-Difluoronitrobenzene (57%).

4519-40-8 Synthesis

4519-40-8
294 suppliers
$10.00/1g

6921-22-8
166 suppliers
$26.00/1g

Yield:6921-22-8 57%

Reaction Conditions:

with dihydrogen peroxide;trifluoroacetic anhydride in dichloromethane;water at 0 - 20;

Steps:

10

To a stirred solution of hydroxy peroxide (30% in H₂O, 35 mL, 356 mmol) under N₂ at0⁰C, a solution of trifluoroacetic anhydride (56 mL, 407 mmol) in 115 mL dichloromethane was added dropwise over 2 h. After addition was complete, a solution of 2,3- difluorobenzenamine (5 g, 39 mmol) in 115 mL dichloromethane was added dropwise at O⁰C. After the addition was complete, the reaction mixture was gradually warmed up to room temperature and stirred overnight. The mixture was extracted by dichloromethane and dried over anhydrous Na₂SO₄. The mixture was filtered and concentrated under reduced pressure. The residue was purified by flash column with 0-15% EtOAc in hexane to yield 3.5 g of 1 ,2- difluoro-3-nitrobenzene (57%). 400 MHz ¹H NMR (CDCI₃) δ (ppm) 7.84 (m, 1H), 7.50 (m, 1H), 7.26 (m, 1H).

References:

WO2008/12623,2008,A1 Location in patent:Page/Page column 62

617-86-7 Synthesis