Hydrochloric Acid → Isopropyl hydrogen 1,3-dithiol-2-ylidenemalonate

HRID 1080749Notes

Reaction equation

HRID 1080749 reaction equation
[S:1]1[CH:5]=[CH:4][S:3][C:2]1=[C:6]([C:13]([O:15]C(C)C)=[O:14])[C:7]([O:9][CH:10]([CH3:12])[CH3:11])=[O:8].[OH-].[K+].Cl>C(O)(C)C>[S:1]1[CH:5]=[CH:4][S:3][C:2]1=[C:6]([C:13]([OH:15])=[O:14])[C:7]([O:9][CH:10]([CH3:12])[CH3:11])=[O:8]

Participants

5

Reactant 3

HCID 313Hydrochloric AcidHCID 4006MalotilateHCID 14797Potassium Hydroxide

Product 1

HCID 14253926Isopropyl hydrogen 1,3-dithiol-2-ylidenemalonateYield 69%

Reagents, catalysts & solvents 1

HCID 3776IsopropanolSolvent

Procedure

A 14.4 g portion of diisopropyl 1,3-dithiol-2-ylidenemalonate (0.05 mol) was dissolved in 50 ml of isopropanol, 2.95 g of potassium hydroxide (0.05 mol) was added to the solution at 30° C., and the resulting mixture was stirred for 1 hour. The solution was acidified with 6N hydrochloric acid and extracted with 200 ml of methylene chloride and washed with water and saturated brine in that order. After drying on magnesium sulfate, the solvent was removed by distillation under a reduced pressure and the resulting residue was crystallized from ether to obtain 8.5 g of isopropyl hydrogen 1,3-dithiol-2-ylidenemalonate in the form of white crystals (yield, 75%). Then, 2.7 g (0.011 mol) of the obtained crystals and 3.6 g (0.012 mol) of 2-chloro-1methylpyridinium p-toluene sulfonate were dissolved in 20 ml of dichloromethane to which was then added dropwise a dichloromethane solution of 0.51 g (0.011 mol) of ethanol and 3.46 g (0.034 mol) of triethylamine at 10° C., subsequently stirring the resulting mixture for 2 hours at room temperature. The reaction solution was poured into ice water, extracted with dichloromethane and then washed with 2N hydrochloric acid, 10% sodium carbonate aqueous solution and water in that order. After drying on magnesium sulfate, the solvent was removed by distillation under a reduced pressure, and the resulting residue was purified by a silica gel column chromatography (n-hexane:ethyl acetate=2:1) to obtain 1.0 g of the title compound in the form of crystals having a melting point of 54° C. (yield, 35%).

Workup

  1. extractionextracted with 200 ml of methylene chloride
  2. washwashed with water and saturated brine in that order
  3. customAfter drying on magnesium sulfate
  4. customthe solvent was removed by distillation under a reduced pressure
  5. customthe resulting residue was crystallized from ether

Sources & evidence

ORD record
ord-e6ed1112b795445e8e701fff89c3b1c2
Source dataset
uspto-grants-1996_12
Patent number
US05583154

Reaction notes

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