Reaction #2186195

Reaction equation

3-benzothiazol-2-yl-7-[4-(2-hydroxy-ethyl)-piperazin-1-yl]-chromen-2-one

diisopropylethylamine

tosyl chloride

→

desired product

Benzothiazol-2-yl-acetic acid methyl ester

Solvents

dichloromethane

Conditions

Workup

1. 1
   Otherto reach room temperature
2. 2
   workup.STIRRINGAfter an additional two hours stirring
3. 3
   Otherthe reaction mixture is evaporated
4. 4
   workup.ADDITIONtreated with 0.2 mL tetrabutylammonium fluoride (1M in THF)
5. 5
   workup.STIRRINGAfter stirring for 30 minutes
6. 6
   Otherthe solution is evaporated

Procedure

10 mg (0.025 mmol) 3-benzothiazol-2-yl-7-[4-(2-hydroxy-ethyl)-piperazin-1-yl]-chromen-2-one are dissolved in 3 mL dichloromethane with 2.5 mg (0.8 eq.) 4-dimethylaminopyridine and 0.013 mL (3 eq.) diisopropylethylamine, and cooled to 0° C. 5.7 mg (1.2 eq.) tosyl chloride are added and the reaction mixture stirred for one hour before being allowed to reach room temperature. After an additional two hours stirring, the reaction mixture is evaporated, the residue taken up in tetrahydrofurane and treated with 0.2 mL tetrabutylammonium fluoride (1M in THF). After stirring for 30 minutes, the solution is evaporated and the desired product obtained as a yellow powder.

Source