Benzyl chloroformate → 2,6-Dimethoxy-4-(methoxy-carbonyl)-carbanilic acid benzyl ester

HRID 542970Notes

Reaction equation

HRID 542970 reaction equation
[CH3:1][O:2][C:3](=[O:15])[C:4]1[CH:9]=[C:8]([O:10][CH3:11])[C:7]([NH2:12])=[C:6]([O:13][CH3:14])[CH:5]=1.[C:16](Cl)([O:18][CH2:19][C:20]1[CH:25]=[CH:24][CH:23]=[CH:22][CH:21]=1)=[O:17]>N1C=CC=CC=1>[CH2:19]([O:18][C:16](=[O:17])[NH:12][C:7]1[C:8]([O:10][CH3:11])=[CH:9][C:4]([C:3]([O:2][CH3:1])=[O:15])=[CH:5][C:6]=1[O:13][CH3:14])[C:20]1[CH:25]=[CH:24][CH:23]=[CH:22][CH:21]=1

Participants

4

Reactant 2

HCID 10387Benzyl chloroformateHCID 123983034-Amino-3,5-dimethoxy-benzoic acid methyl ester

Product 1

HCID 542260132,6-Dimethoxy-4-(methoxy-carbonyl)-carbanilic acid benzyl ester

Reagents, catalysts & solvents 1

HCID 1049PyridineSolvent

Procedure

A solution of 50.6 g. of 4-amino-3,5-dimethoxy-benzoic acid methyl ester in 1 liter of absolute pyridine was treated during 30 minutes with 82 g. of carbobenzoxy chloride with stirring and ice-cooling. Thereafter, the mixture was stirred at room temperature for 20 hours. The pyridine was evaporated under vacuum and the residue treated with 1 liter of water and 3N hydrochloric acid to obtain a strongly acidic reaction. The resulting emulsion was extracted with two 1.5 liter portions of ethyl acetate. The ethyl acetate extract was washed with two 800 ml. portions of water, dried over magnesium sulfate and evaporated under vacuum. After recrystallization of the residue from ethyl acetate, there was obtained 2,6-dimethoxy-4-(methoxy-carbonyl)-carbanilic acid benzyl ester having a melting point of 132°-133° C.

Workup

  1. temperatureice-cooling
  2. customThe pyridine was evaporated under vacuum
  3. additionthe residue treated with 1 liter of water and 3N hydrochloric acid
  4. customto obtain
  5. customa strongly acidic reaction
  6. extractionThe resulting emulsion was extracted with two 1.5 liter portions of ethyl acetate
  7. extractionThe ethyl acetate extract
  8. washwas washed with two 800 ml
  9. dry with materialportions of water, dried over magnesium sulfate
  10. customevaporated under vacuum
  11. customAfter recrystallization of the residue from ethyl acetate

Sources & evidence

ORD record
ord-e3bbb713e68841c7ab695dc5fc0d3c19
Source dataset
uspto-grants-1987_04
Patent number
US04659818

Reaction notes

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