Reaction #49734

Reaction equation

sodium chloride

n-butyllithium

[2-chloro-4-(methylsulphenyl)phenyl]acetylene

cyclopropanecarbonyl chloride

→

1-[2-chloro-4-(methylsulphenyl)phenyl]-3-cyclopropylprop-1-yn-3-one

Solvents

hexane

THF

Conditions

Workup

1. 1
   Temperaturewhile maintaining the temperature below -70° C
2. 2
   ExtractionThe aqueous layer was extracted with ether
3. 3
   Dryingdried (MgSO4)
4. 4
   Filtrationfiltered
5. 5
   OtherThe filtrate was evaporated to dryness
6. 6
   workup.DISSOLUTIONthe residue was dissolved in methanol
7. 7
   Temperatureheated
8. 8
   Temperatureat reflux for 5 minutes
9. 9
   workup.ADDITIONToluene was added
10. 10
    Otherthe mixture was evaporated to dryness
11. 11
    OtherThe residue was purified by chromatography
12. 12
    Washeluted with a mixture of hexane and ether

Procedure

A solution of n-butyllithium in hexane (4.4 ml) was added to a stirred solution of [2-chloro-4-(methylsulphenyl)phenyl]acetylene (2.0 g) in THF while maintaining the temperature below -70° C. The mixture was stirred for 5 minutes and cyclopropanecarbonyl chloride (2.4 g) was added. The mixture was warmed to room temperature and poured onto aqueous sodium chloride solution. The aqueous layer was extracted with ether and combined organic layers dried (MgSO4) and filtered. The filtrate was evaporated to dryness and the residue was dissolved in methanol and heated at reflux for 5 minutes. Toluene was added and the mixture was evaporated to dryness. The residue was purified by chromatography eluted with a mixture of hexane and ether to give 1-[2-chloro-4-(methylsulphenyl)phenyl]-3-cyclopropylprop-1-yn-3-one as yellow oil which crystallized on standing, m.p. 46°-50° C. [2-Chloro-4-(methylsulphenyl)phenyl]acetylene was prepared by the reaction of 1-bromo-2-[2-chloro-4-(methylsulphenyl)phenyl]acetylene with n-butyllithium and wet zinc chloride in THF at -70° C.

Source