Reaction #657290

Reaction equation

sodium carbonate

3-(2,5-dimethyl-phenyl)-4-hydroxy-8-methoxy-1-methyl-1,8-diaza-spiro[4.5]dec-3-en-2-one

sodium hydrogen carbonate

sulfuryl chloride

→

3-Chloro-3-(2,5-dimethyl-phenyl)-8-methoxy-1-methyl-1,8-diaza-spiro[4.5]decane-2,4-dione

Solvents

chloroform

chloroform

Conditions

Workup

1. 1
   Otherthe layers separated
2. 2
   Extractionthe water phase extracted with ethyl acetate (3×20 ml)
3. 3
   Washthe combined organic phases washed with saturated aqueous sodium carbonate and brine
4. 4
   Dryingdried over sodium sulfate
5. 5
   Concentrationconcentrated
6. 6
   OtherThe residue was purified by chromatography on silica gel (ethyl acetate/cyclohexane 2:1)

Procedure

To a solution of 3-(2,5-dimethyl-phenyl)-4-hydroxy-8-methoxy-1-methyl-1,8-diaza-spiro[4.5]dec-3-en-2-one (compound P2.1) (35 mg, 0.111 mmol) and sodium hydrogen carbonate (23 mg, 0.274 mmol) in chloroform (5 ml) at −5° C. was added sulfuryl chloride (0.009 ml, 15.0 mg, 0.111 mmol) in chloroform (0.25 ml) dropwise. The reaction mixture was stirred at 0° C. for 30 minutes and at room temperature overnight, poured on saturated aqueous sodium carbonate, the layers separated, the water phase extracted with ethyl acetate (3×20 ml), the combined organic phases washed with saturated aqueous sodium carbonate and brine, dried over sodium sulfate and concentrated. The residue was purified by chromatography on silica gel (ethyl acetate/cyclohexane 2:1). Yield: 26 mg of 3-chloro-3-(2,5-dimethyl-phenyl)-8-methoxy-1-methyl-1,8-diaza-spiro[4.5]decane-2,4-dione (title compound P1.5) as a pale yellow gum.

Source