Methanethiol → HCID 54141775, compound

HRID 2166314Notes

Reaction equation

HRID 2166314 reaction equation
[CH3:1][SH:2].BrBr.[CH3:5][C:6]([CH3:14])([CH:12]=[CH2:13])[C:7]([O:9]CC)=[O:8]>C(Cl)(Cl)(Cl)Cl>[CH3:5][C:6]([CH3:14])([CH:12]=[CH:13][S:2][CH3:1])[C:7]([OH:9])=[O:8]

Participants

5

Reactant 3

HCID 878MethanethiolHCID 24408BromineHCID 344890ethyl 2,2-dimethylbut-3-enoate

Product 1

HCID 54141775HCID 54141775, compoundYield 52.1%

Reagents, catalysts & solvents 1

HCID 5943Carbon TetrachlorideSolvent

Procedure

A solution of methanethiol (8 g) in CCl4 was stirred and treated dropwise at -25° C. with bromine (26.6 g). Ethyl 2,2-dimethyl-3-butenoate (23 g) was then added dropwise at that temperature over two hours. Following the addition, the solution was allowed to warm to room temperature, then concentrated in vacuo. NMR showed near complete conversion to the 4-bromo-3-methylthio ester (38 g). The residual oil was then heated one hour on a steam bath to effect conversion to the thermodynamically favored 3-bromo-4-methylthio ester. This material was then dissolved in 50 mL of DMF and treated with 26 g of DBU. The solution was heated briefly on a steam bath, then was allowed to cool and worked up by pouring into water, extracting with 2×200 mL of ether, drying and concentrating. The residual oil (24.75 g) was hydrolyzed by stirring overnight in a solution of 50 mL of ethanol, 15 mL of water and 7.8 g of sodium hydroxide. Acidification with 1N HCl and extraction into ether followed by drying and concentration furnished a solid which was recrystallized from ether/hexane to give 13.5 g of 2,2-dimethyl-4-methylthio-3-butenoic acid, m.p. 49°-51° C.

Workup

  1. additionthe addition
  2. concentrationconcentrated in vacuo
  3. temperatureThe residual oil was then heated one hour on a steam bath
  4. dissolutionThis material was then dissolved in 50 mL of DMF
  5. additiontreated with 26 g of DBU
  6. temperatureThe solution was heated briefly on a steam bath
  7. temperatureto cool
  8. additionby pouring into water
  9. extractionextracting with 2×200 mL of ether
  10. customdrying
  11. concentrationconcentrating
  12. extractionAcidification with 1N HCl and extraction into ether
  13. customby drying
  14. concentrationconcentration
  15. customfurnished a solid which
  16. customwas recrystallized from ether/hexane

Sources & evidence

ORD record
ord-b5a469b1640a4f23842b143b57e56afb
Source dataset
uspto-grants-1990_07
Patent number
US04944795

Reaction notes

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