Reacción #79338

Ecuación de reacción

Triphenylphospine

2-Bromo-5-fluorobenzoic acid

N,O-Dimethylhydroxylamine hydrochloride

triethylamine

→

2-bromo-5-fluoro-N-methoxy-N-methylbenzamide

Rendimiento 73.0%

Disolventes

methylene chloride

Condiciones de reacción

Tratamiento posterior

1. 1
   ConcentraciónThe solution was concentrated to an oil
2. 2
   workup.ADDITIONHexanes (100 mL) and Ethyl Acetate (100 mL) were added to the oil
3. 3
   workup.STIRRINGstirred for 1 hour
4. 4
   Filtraciónthen filtered
5. 5
   ConcentraciónThe filtrate was concentrated
6. 6
   Otrothe residue was purified by chromatography (Hexanes/Ethyl Acetate) on silica gel

Procedimiento

2-Bromo-5-fluorobenzoic acid (4.60 g, 0.02 mol), N,O-Dimethylhydroxylamine hydrochloride (2.05 g, 0.02 mol), carbon tertabromide (6.9 g, 0.02 mol) was added to mixture of methylene chloride (100 mL) and triethylamine (2.9 mL, 0.02 mol). Triphenylphospine (5.53 g, 0.02 mol) was added to the solution over 1 hour and stirred for another 1 hour. The solution was concentrated to an oil. Hexanes (100 mL) and Ethyl Acetate (100 mL) were added to the oil and stirred for 1 hour then filtered. The filtrate was concentrated and the residue was purified by chromatography (Hexanes/Ethyl Acetate) on silica gel to afford 2-bromo-5-fluoro-N-methoxy-N-methylbenzamide as a foamy white solid in 73% yield. 1H NMR (CDCl3, 500 MHz) δ3.00-3.98 (m, 6 H), 6.97-7.08 (m, 2H), 7.51-7.54 (m, 1H).

Fuente