Reaction #1543043

Reaction equation

2-chloro-4-methylsulfonylbenzoyl chloride

aluminum chloride

1,1,2,2-tetrachloroethane

hydrochloric acid

→

2,2', 4'-Trichloro-6'-hydroxy-4-methylsulfonylbenzophenone

Conditions

Workup

1. 1
   Temperaturethe mixture is subsequently refluxed for 7 hours
2. 2
   OtherThe organic phase is removed
3. 3
   Extractionthe aqueous phase is extracted twice
4. 4
   WashThe combined organic phases are washed until neutral and
5. 5
   Extractionsubsequently extracted three times
6. 6
   FiltrationThe precipitate is filtered off
7. 7
   Washwashed with water until neutral and
8. 8
   Otherdried

Procedure

3.00 g of 2-chloro-4-methylsulfonylbenzoyl chloride are added in portions at room temperature to a mixture of 1.97 g of 3,5-dichlorophenone and 3.23 g of aluminum chloride in 50 ml of 1,1,2,2-tetrachloroethane, and the mixture is subsequently refluxed for 7 hours. When cold, the reaction mixture is poured onto 100 g of ice and 20 ml of concentrated hydrochloric acid. The organic phase is removed, and the aqueous phase is extracted twice using 50 ml of dichloromethane. The combined organic phases are washed until neutral and subsequently extracted three times using in each case 25 ml of 2N sodium hydroxide solution. The combined alkaline extracts are brought to a pH of 2 using concentrated hydrochloric acid. The precipitate is filtered off, washed with water until neutral and dried. This gives 3.194 g (70% of theory) of 2,2', 4'-trichloro-6'-hydroxy-4-methylsulfonylbenzophenone in the form of colorless crystals with a melting point of 123°-126° C.

Source