Reaction #2186208

Reaction equation

sodium bicarbonate

3-Benzothiazol-2-yl-7-[4-(3-hydroxy-propyl)-piperazin-1-yl]-chromen-2-one

Hünig base

tosyl chloride

→

Toluene-4-sulfonic acid 3-[4-(3-benzothiazol-2-yl-2-oxo-2H-chromen-7-yl)-piperazin-1-yl]-propyl ester

Solvents

dichloromethane

Conditions

Workup

1. 1
   workup.ADDITIONpoured onto ice
2. 2
   Extractionextracted (dichloromethane, saline)
3. 3
   OtherThe organic phase is evaporated
4. 4
   Otherthe residue column chromatographed (silica gel, dichloromethane/EtOH 98:2)
5. 5
   Otherto yield
6. 6
   Otherafter evaporation
7. 7
   Dryingdrying under high vacuum 73 mg (78%) desired product as a light brownish powder

Procedure

70 mg (0.16 mmol) 3-Benzothiazol-2-yl-7-[4-(3-hydroxy-propyl)-piperazin-1-yl]-chromen-2-one are dissolved in 15 mL dichloromethane under argon. 0.083 mL Hünig base and 10 mg DMAP are added to the stirred solution, followed by 46 mg (1.5 eq.) tosyl chloride. The reaction mixture is stirred for 20 h at room temperature, poured onto ice, treated with 2 mL aqueous sodium bicarbonate solution and extracted (dichloromethane, saline). The organic phase is evaporated and the residue column chromatographed (silica gel, dichloromethane/EtOH 98:2) to yield after evaporation and drying under high vacuum 73 mg (78%) desired product as a light brownish powder.

Source