Reaction #1597015

Reaction equation

salicylic acid

2-chloro-4-nitroaniline

phosphorous trichloride

dichloromethane

→

title compound

N-(2-chloro-4-nitrophenyl)-2 hydroxybenzamide

Solvents

Conditions

Workup

1. 1
   TemperatureThe solution was cooled to about 125° C
2. 2
   Temperatureto cool to room temperature
3. 3
   OtherThe product separated
4. 4
   Filtrationwas collected by filtration
5. 5
   Washwashed with hexanes
6. 6
   Otherrecrystallized from ethanol

Procedure

The method disclosed in U.S. Pat. No. 3,079,297 to Shraufstatter et al with minor variations was utilized. A boiling solution of salicylic acid (1.03 g, 7.46 mmol) and 2-chloro-4-nitroaniline (1.29 g, 7.46 mmol) in xylenes (20 mL) was treated dropwise with a solution of phosphorous trichloride in dichloromethane 2.0M, 1.50 mL, 0.40 equiv.), and the resulting solution was refluxed (137° C.) for four hours. The solution was cooled to about 125° C. An oily residue covered the bottom and sides of the reaction vessel. The hot reaction solution was transferred by glass pipette to a beaker and was allowed to cool to room temperature while being stirred rapidly. The product separated, was collected by filtration, and washed with hexanes, then recrystallized from ethanol. The title compound was obtained, MP 218-220° C. (dec.). 1HNMR (500 MHz, DMSO-d6): δ 7.02 (m, 1H, H3), 7.07 (m, 1H, H5), 7.49 (m, 1H, H4), 8.04 (m, 1H, H6), 8.28 (m, 1H, H5′), 8.41 (m, 1H, H3′), 8.85 (m, 1H, H6′), 11.8 (s, 1H, NH), 12.34 (s, 1H, OH).

Source