Reaction #2186200

Reaction equation

3-benzothiazol-2-yl-7-piperazin-1-yl-chromen-2-one

cesium carbonate

2-iodoethanol

→

desired product

Yield 26.0%

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

Yield 26.0%

Solvents

DMF

Conditions

Workup

1. 1
   ExtractionThe reaction mixture is extracted with ethyl acetate
2. 2
   Washa saturated solution of sodium carbonate and washed with brine
3. 3
   DryingThe combined organic phases are dried with sodium sulphate
4. 4
   Otherevaporated
5. 5
   Otherchromatographed (silica gel, dichloromethane/methanol 95:5+1% conc. NH4OH)

Procedure

240 mg crude 3-benzothiazol-2-yl-7-piperazin-1-yl-chromen-2-one in 10 mL DMF are stirred for 72 h at room temperature in the presence of 858 mg (at least 4 eq.) cesium carbonate and 0.103 mL (at least 2 eq.) 2-iodoethanol. The reaction mixture is extracted with ethyl acetate and a saturated solution of sodium carbonate and washed with brine. The combined organic phases are dried with sodium sulphate and evaporated. The residue is column chromatographed (silica gel, dichloromethane/methanol 95:5+1% conc. NH4OH) to yield 70 mg (26%) desired product as an orange solid.

Source