Hydrochloric Acid → 4-Chloro-3,5-diethoxybenzoic acid ethyl ester

HRID 2426587Notes

Reaction equation

HRID 2426587 reaction equation
[CH2:1]([O:3][C:4](=[O:18])[C:5]1[CH:10]=[C:9]([O:11][CH2:12][CH3:13])[C:8](N)=[C:7]([O:15][CH2:16][CH3:17])[CH:6]=1)[CH3:2].[ClH:19].N([O-])=O.[Na+].[OH-].[Na+]>O.[Cu]Cl>[CH2:1]([O:3][C:4](=[O:18])[C:5]1[CH:10]=[C:9]([O:11][CH2:12][CH3:13])[C:8]([Cl:19])=[C:7]([O:15][CH2:16][CH3:17])[CH:6]=1)[CH3:2]

Participants

7

Reactant 4

HCID 313Hydrochloric AcidHCID 14798Sodium HydroxideHCID 123984444-Amino-3,5-diethoxybenzoic acid ethyl esterHCID 23668193Sodium Nitrite

Product 1

HCID 596847734-Chloro-3,5-diethoxybenzoic acid ethyl ester

Reagents, catalysts & solvents 2

HCID 62652Cuprous chlorideCatalystHCID 962WaterSolvent

Conditions

Temperature
0 °C

Procedure

To a solution of 4-amino-3,5-diethoxy-benzoic acid ethyl ester (5.1 g, 20.13 mmol, 1.0 equiv; prepared as described in I. Kompis and A. Wick, Helv. Chim. Acta 1977, 60, 3025-3034) in water (40 mL) and 37% HCl (40 mL) at 0° C. was added sodium nitrite (1.67 g, 24.16 mmol, 1.2 equiv). After 10 min, copper(I) chloride (12.0 g, 120.81 mmol, 6.0 equiv) was added, the reaction mixture stirred for an additional 5 h at 0° C. and then the ice bath removed. After stirring for 18 h, the crude reaction mixture was adjusted to pH=8 by addition of a solution of 1 M NaOH and the aqueous layer extracted with ethyl acetate (3×100 mL). The combined organic phases were dried over MgSO4, concentrated by evaporation under reduced pressure and the crude material purified by silica column chromatography using a MPLC system (CombiFlash Companion, Isco Inc.) eluting with a gradient of heptane/ethyl acetate providing 5.0 g (91%) of the title compound. 1H NMR (300 MHz, CDCl3): δ1.32 (t, J=7.0 Hz, 4H), 1.40 (t, J=7.0 Hz, 6H), 4.09 (q, J=7.0 Hz, 4H), 4.30 (q, J=7.0 Hz, 2H), 7.18 (s, 2H). 13C NMR (75 MHz, CDCl3): δ13.33, 13.66, 60.29, 64.16, 105.75, 115.88, 128.25, 154.49, 165.01. MS (ISP): 273.3 [M+H]+.

Workup

  1. customprepared
  2. customthe ice bath removed
  3. stirringAfter stirring for 18 h
  4. customthe crude reaction mixture
  5. extractionthe aqueous layer extracted with ethyl acetate (3×100 mL)
  6. dry with materialThe combined organic phases were dried over MgSO4
  7. concentrationconcentrated by evaporation under reduced pressure
  8. customthe crude material purified by silica column chromatography
  9. washeluting with a gradient of heptane/ethyl acetate providing 5.0 g (91%) of the title compound

Sources & evidence

ORD record
ord-1c8711b4d1bd4180b97eaa8b763efada
Source dataset
uspto-grants-2011_06
Patent number
US07968568B2

Reaction notes

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