Reaction #5936

Reaction equation

chloroacetyl chloride

(R)-(+)-2-(4-chlorophenyl)-3,4-dihydro-2H-1,4-benzothiazine

triethylamine

→

(R)-4-chloroacetyl-2-(4-chlorophenyl)-3,4-dihydro-2H-1,4-benzothiazine

Yield 108.8%

Solvents

dichloromethane

dichloromethane

Conditions

Workup

1. 1
   workup.DISTILLATIONAfter the solvent is distilled off, to the residue
2. 2
   workup.ADDITIONare added ethyl acetate and water
3. 3
   Washthe ethyl acetate layer is washed with aqueous sodium hydrogen carbonate solution, water and saline
4. 4
   Dryingdried over sodium sulfate
5. 5
   workup.DISTILLATIONdistilled
6. 6
   Otherto remove the solvent

Procedure

To a suspension of (R)-(+)-2-(4-chlorophenyl)-3,4-dihydro-2H-1,4-benzothiazine (1.30 g, 0.005 mole) and triethylamine (1.66 ml, 0.012 mole) in dichloromethane (16 ml) is added dropwise a solution of chloroacetyl chloride (0.79 ml, 0.01 mole) in dichloromethane (4 ml) under ice cooling, and the mixture is stirred at room temperature for 45 minutes. After the solvent is distilled off, to the residue are added ethyl acetate and water, and the ethyl acetate layer is washed with aqueous sodium hydrogen carbonate solution, water and saline, dried over sodium sulfate and distilled to remove the solvent to give (R)-4-chloroacetyl-2-(4-chlorophenyl)-3,4-dihydro-2H-1,4-benzothiazine (1.84 g) as caramel.

Source