Reaction #1893

Reaction equation

2-amino-5-chloro-2'-methoxybenzophenone

sodium bicarbonate

→

2-amino-5-chloro-2'-hydroxybenzophenone

Yield 93.4%

Solvents

hydrogen bromide

Conditions

Workup

1. 1
   Temperaturewas heated for 1 hour
2. 2
   Temperatureunder reflux
3. 3
   Extractionsubjected to extraction with 100 ml of ethyl acetate
4. 4
   WashThe extract solution was washed with water
5. 5
   Dryingdried over anhydrous magnesium sulfate
6. 6
   workup.DISTILLATIONthe solvent was then distilled off under reduced pressure
7. 7
   OtherThe residue was purified by means of silica gel column chromatography (eluent, hexane:ethyl acetate=10:1)

Procedure

A mixture of 2.15 g of 2-amino-5-chloro-2'-methoxybenzophenone and 20 ml of 47% hydrogen bromide was heated for 1 hour under reflux. The solution was rendered neutral with sodium bicarbonate, and subjected to extraction with 100 ml of ethyl acetate. The extract solution was washed with water and dried over anhydrous magnesium sulfate; the solvent was then distilled off under reduced pressure. The residue was purified by means of silica gel column chromatography (eluent, hexane:ethyl acetate=10:1) to yield 1.9 g of 2-amino-5-chloro-2'-hydroxybenzophenone as needles, m.p. 51° to 52° C.

Source