Tin tetrachloride → 3-Amino-4-chloro-5-ethoxy-benzoic acid methyl ester

HRID 1990862Notes

Reaction equation

HRID 1990862 reaction equation
[CH3:1][O:2][C:3](=[O:17])[C:4]1[CH:9]=[C:8]([N+:10]([O-])=O)[C:7]([Cl:13])=[C:6]([O:14][CH2:15][CH3:16])[CH:5]=1.[Sn](Cl)(Cl)(Cl)Cl>CO.Cl>[CH3:1][O:2][C:3](=[O:17])[C:4]1[CH:5]=[C:6]([O:14][CH2:15][CH3:16])[C:7]([Cl:13])=[C:8]([NH2:10])[CH:9]=1

Participants

5

Reactant 2

HCID 24287Tin tetrachlorideHCID 686994194-Chloro-3-ethoxy-5-nitro-benzoic acid methyl ester

Product 1

HCID 686990463-Amino-4-chloro-5-ethoxy-benzoic acid methyl ester

Reagents, catalysts & solvents 2

HCID 313Hydrochloric AcidSolventHCID 887MethanolSolvent

Procedure

To a solution of 4-chloro-3-ethoxy-5-nitro-benzoic acid methyl ester (1.0 g, 3.85 mmol, 1.0 equiv) in methanol (20 mL) was added dropwise under stirring at 0° C. a solution of tin chloride (2.92 g, 15.41 mmol, 4.0 equiv) in 37% HCl (7.5 mL). After the addition was completed the cooling bath was removed and the reaction mixture stirred at rt for 18 h. The solution was concentrated by evaporation under reduced pressure and the solution extracted with ethyl acetate (3×100 mL). The combined organic phases were dried over MgSO4, the solvent removed by evaporation under reduced pressure and the crude material purified by recrystallization from dichloromethane yielding 0.88 g (100%) of the title compound. 1H NMR (300 MHz, DMSO): δ 1.28 (t, J=7.0 Hz, 3H), 3.75 (s, 3H), 4.01 (q, J=7.0 Hz, 2H), 5.57 (br s, 2H), 6.71 (d, J=1.7 Hz, 1H), 7.03 (d, J=1.7 Hz, 1H). 13C NMR (75 MHz, DMSO): δ 14.51, 52.09, 64.31, 100.87, 108.93, 110.33, 128.52, 145.93, 154.51, 166.10. MS (ISP): 230.0 [M+H]+.

Workup

  1. additionAfter the addition
  2. customwas removed
  3. concentrationThe solution was concentrated by evaporation under reduced pressure
  4. extractionthe solution extracted with ethyl acetate (3×100 mL)
  5. dry with materialThe combined organic phases were dried over MgSO4
  6. customthe solvent removed by evaporation under reduced pressure
  7. customthe crude material purified by recrystallization from dichloromethane yielding 0.88 g (100%) of the title compound

Sources & evidence

ORD record
ord-ba52e64bb49c45258447681b1f53b957
Source dataset
uspto-grants-2010_01
Patent number
US07645753B2

Reaction notes

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