Chlorosulfonyl isocyanate → 5-Cyano-2-ethoxy-4-methoxy-benzoic acid ethyl ester

HRID 2105840Notes

Reaction equation

HRID 2105840 reaction equation
[CH2:1]([O:3][C:4](=[O:16])[C:5]1[CH:10]=[CH:9][C:8]([O:11][CH3:12])=[CH:7][C:6]=1[O:13][CH2:14][CH3:15])[CH3:2].ClS([N:21]=[C:22]=O)(=O)=O>ClCCCl.C(Cl)Cl.O>[CH2:1]([O:3][C:4](=[O:16])[C:5]1[CH:10]=[C:9]([C:22]#[N:21])[C:8]([O:11][CH3:12])=[CH:7][C:6]=1[O:13][CH2:14][CH3:15])[CH3:2]

Participants

6

Reactant 2

HCID 70918Chlorosulfonyl isocyanateHCID 670715012-Ethoxy-4-methoxybenzoic acid ethyl ester

Product 1

HCID 688714495-Cyano-2-ethoxy-4-methoxy-benzoic acid ethyl esterYield 54%

Reagents, catalysts & solvents 3

HCID 111,2-DichloroethaneSolventHCID 962WaterSolventHCID 6344DichloromethaneSolvent

Conditions

Temperature
50 °C

Procedure

To a stirring solution of 2-ethoxy-4-methoxy-benzoic acid ethyl ester (1.5 g, 6.7 mmol) in 1,2-dichloroethane (2 mL) was added chlorosulfonyl isocyanate (0.923 mL, 10.6 mmol, in 1 mL of 1,2-dichloroethane) in several portions. The reaction was stirred at 50° C. overnight. Reaction was diluted with methylene chloride (2 mL) and water (1 mL), and extracted. The organic layer was washed with brine and concentrated in vacuo. Purification of the crude residue by flash column chromatography (silica gel, eluting with a gradient of ethyl acetate in hexanes) gave 900 mg (54% yield) of 5-cyano-2-ethoxy-4-methoxy-benzoic acid ethyl ester. LC-MS: 236.2 [(M+H—CH3)+].

Workup

  1. customReaction
  2. extractionextracted
  3. washThe organic layer was washed with brine
  4. concentrationconcentrated in vacuo
  5. customPurification of the crude residue by flash column chromatography (silica gel
  6. washeluting with a gradient of ethyl acetate in hexanes)

Sources & evidence

ORD record
ord-3963d5147c654160b6625bd750ffcdcd
Source dataset
uspto-grants-2009_08
Patent number
US07579368B2

Reaction notes

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