Hydrochloric Acid → Methyl 2-hydroxy-1-methoxy-5-methyl-4-oxocyclohex-2-enecarboxylate

HRID 2180906Notes

Reaction equation

HRID 2180906 reaction equation
C[O-].[Na+].[CH3:4][C:5](=[CH2:9])[C:6](=[O:8])[CH3:7].[CH3:10][O:11][C:12](=[O:20])[CH:13]([O:18][CH3:19])[C:14](OC)=[O:15].Cl>CS(C)=O>[CH3:10][O:11][C:12]([C:13]1([O:18][CH3:19])[CH2:9][CH:5]([CH3:4])[C:6](=[O:8])[CH:7]=[C:14]1[OH:15])=[O:20]

Participants

6

Reactant 4

HCID 313Hydrochloric AcidHCID 13143Methyl isopropenyl ketoneHCID 78718Dimethyl methoxymalonateHCID 10942334Sodium Methoxide

Product 1

HCID 18755506Methyl 2-hydroxy-1-methoxy-5-methyl-4-oxocyclohex-2-enecarboxylate

Reagents, catalysts & solvents 1

HCID 679Dimethyl SulfoxideSolvent

Conditions

Temperature
35 °C

Procedure

A 30% solution of 35.8 g of sodium methanolate is made up in 65 ml of dimethyl sulfoxide and, over a period of 20 minutes, is treated at a temperature of from 30 to 35° C. with a mixture of 16.7 g of 3-methyl-3-buten-2-one and 32.4 g of methoxymalonic acid dimethyl ester. The mixture is stirred for 1 hour at a temperature of 35° C., acidified with hydrochloric acid and then extracted several times with dichloromethane. The organic phases are washed with water, dried and concentrated. By crystallising from hot ethyl acetate and hexane, pure 2-hydroxy-1-methoxy-5-methyl-4-oxo-cyclohex-2-enecarboxylic acid methyl ester having a melting point of 117-117.5° C. is obtained.

Workup

  1. extractionextracted several times with dichloromethane
  2. washThe organic phases are washed with water
  3. customdried
  4. concentrationconcentrated
  5. customBy crystallising from hot ethyl acetate and hexane, pure 2-hydroxy-1-methoxy-5-methyl-4-oxo-cyclohex-2-enecarboxylic acid methyl ester having a melting point of 117-117.5° C.
  6. customis obtained

Sources & evidence

ORD record
ord-07fc7da87a2f4445a1d837c5538d3349
Source dataset
uspto-grants-2005_05
Patent number
US06890885B2

Reaction notes

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