Dimethyl Sulfoxide → Butanoic acid, 2-[bis(methylthio)methylene]-3-oxo-, ethyl ester
Reaction equation
[C:1]([O:7][CH2:8][CH3:9])(=[O:6])[CH2:2][C:3]([CH3:5])=[O:4].[C:10](=S)=[S:11].[H-].[Na+].CI.[CH3:17][S:18]([CH3:20])=O>O>[CH3:17][S:18][C:20]([S:11][CH3:10])=[C:2]([C:3](=[O:4])[CH3:5])[C:1]([O:7][CH2:8][CH3:9])=[O:6]Participants
Procedure
A solution of 6.50 g (50.0 mmol) of ethyl acetoacetate and 4.18 g (3.30 mL, 55.0 mmol) of carbon disulfide in 60 mL of dry dimethylsulfoxide in a flame-dried 300 mL flask was treated portionwise at 16-18° C. with 2.64 g (110 mmol) of oil-free sodium hydride. An additional 100 mL of dimethylsulfoxide was eventually added to facilitate stirring. After the addition was complete, the deep red solution was stirred for 75 minutes and then was quenched with 15.62 g (6.85 mL, 110 mmol) of methyl iodide. The reaction mixture was stirred overnight at room temperature. The solution was poured into water and extracted with ether. The extracts were washed with water, dried and evaporated to give a red oil which was used for subsequent reactions without further purification. 1H-NMR (CDCl3) δ 1.24 (3H, t, J=7), 2.28 (3H, s), 2.37 (6H,s), 4.21 (2H, q, J=7).
Workup
- additionAfter the addition
- stirringthe deep red solution was stirred for 75 minutes
- stirringThe reaction mixture was stirred overnight at room temperature
- extractionextracted with ether
- washThe extracts were washed with water
- customdried
- customevaporated
- customto give a red oil which
- customwas used for subsequent reactions without further purification
Sources & evidence
- ORD record
- ord-5e877341ff0f486ea5a3524676e722c5
- Source dataset
- uspto-grants-1999_10
- Patent number
- US05968944
Reaction notes
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