Hydrogen Sulfide → Dimethyl 3-thienylmalonate

HRID 1414135Notes

Reaction equation

HRID 1414135 reaction equation
[OH-].[K+].[SH2:3].[CH3:4][O:5][C:6](=[O:18])[C:7]([C:14]([O:16][CH3:17])=[O:15])=[C:8]([CH2:12]Cl)[CH:9]=[CH:10]Cl>C(O)C.O.CCOCC>[S:3]1[CH:10]=[CH:9][C:8]([CH:7]([C:14]([O:16][CH3:17])=[O:15])[C:6]([O:5][CH3:4])=[O:18])=[CH:12]1

Participants

7

Reactant 3

HCID 402Hydrogen Sulfide3×HCID 14797Potassium Hydroxide2×HCID 54249168Methyl-2-methoxycarbonyl-5-chloro-3-chloromethylpenta-2,4-dienoate

Product 1

HCID 12509453Dimethyl 3-thienylmalonateYield 74%

Reagents, catalysts & solvents 3

HCID 702EthanolSolventHCID 962WaterSolventHCID 3283Diethyl EtherSolvent

Procedure

Potassium hydroxide (0.14 g, 2.0 mmol) in ethanol (50 ml) was saturated with hydrogen sulphide at 0° C. To this was added methyl-2-methoxycarbonyl-5-chloro-3-chloromethylpenta-2,4-dienoate (0.62 g, 2.45 mmol) and addition of hydrogen sulphide was continued for 1 hour at room temperature. The reaction mixture was stirred for a further 4 hours. Potassium hydroxide (0.20 g, 2.8 mmol) was added and hydrogen sulphide passed for 0.5 hours. The reaction mixture was stirred at room temperature for 16 hours, diluted with water and ether extracted. The extracts were washed with saturated brine, dried and evaporated to give the title compound (0.39 g, 74%), b.p. 96°-98° C./0.3 mm. δ (CDCl3) 3.77 (6H, s, 2×CH3), 4.82 (1H, s, CH), 7.11-7.48 (3H, m, thienyl protons). νmax (film) 1740 cm-1C9H10O4S requires M,214. Found: M+, 214.

Workup

  1. additionTo this was added
  2. stirringThe reaction mixture was stirred at room temperature for 16 hours
  3. extractionextracted
  4. washThe extracts were washed with saturated brine
  5. customdried
  6. customevaporated

Sources & evidence

ORD record
ord-49baa2aaa8e6412ca0daab95ffa9a19a
Source dataset
uspto-grants-1981_02
Patent number
US04252976

Reaction notes

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