Hydrochloric Acid → (+/-)-2-Amino-3-(3,4-dichloro-phenyl)-3-oxo-propionic acid methyl ester hydrochloride

HRID 2265209Notes

Reaction equation

HRID 2265209 reaction equation
[CH3:1][O:2][C:3]([C:5]1[N:6]=C[O:8][C:9]=1[C:10]1[CH:15]=[CH:14][C:13]([Cl:16])=[C:12]([Cl:17])[CH:11]=1)=[O:4].Cl>CO>[ClH:16].[CH3:1][O:2][C:3](=[O:4])[CH:5]([NH2:6])[C:9]([C:10]1[CH:15]=[CH:14][C:13]([Cl:16])=[C:12]([Cl:17])[CH:11]=1)=[O:8]

Participants

4

Reactant 2

HCID 313Hydrochloric AcidHCID 687696805-(3,4-Dichloro-phenyl)-oxazole-4-carboxylic acid methyl ester

Product 1

HCID 68768647(+/-)-2-Amino-3-(3,4-dichloro-phenyl)-3-oxo-propionic acid methyl ester hydrochlorideYield 121.6%

Reagents, catalysts & solvents 1

HCID 887MethanolSolvent

Conditions

Temperature
50 °C

Procedure

A suspension of 5-(3,4-dichloro-phenyl)-oxazole-4-carboxylic acid methyl ester (1.5 g, 5.51 mmol), 3 N HCl (10 mL), and MeOH (15 mL) was heated at 50° C. for 4 h. The mixture was concentrated, diluted with water, and washed with Et2O. The aqueous layer was concentrated and Et2O was added, causing precipitation of a white solid. The precipitate was collected by filtration to provide 1.0 g (63%) of the desired product as an apparent 10:1 mixture of keto-enol tautomers. MS (ESI+): mass calcd. for C10H9Cl2NO3, 261.00; m/z found, 262/264 [M+H]+. Major tautomer: 1H NMR (500 MHz, CDCl3): 8.32 (d, J=2.1, 1H), 8.09 (dd, J=8.4, 2.1, 1H), 7.79 (d, J=8.5, 1H), 3.80 (s, 3H). Minor tautomer: 1H NMR (500 MHz, CDCl3): 8.19 (d, J=2.0, 1H), 7.96 (dd, J=8.4, 2.1, 1H), 7.76 (d, J=8.4, 1H), 6.18 (s, 1H).

Workup

  1. concentrationThe mixture was concentrated
  2. additiondiluted with water
  3. washwashed with Et2O
  4. concentrationThe aqueous layer was concentrated
  5. additionEt2O was added
  6. customprecipitation of a white solid
  7. filtrationThe precipitate was collected by filtration

Sources & evidence

ORD record
ord-ab234983977d4db2ae56f77fe645d9c9
Source dataset
uspto-grants-2010_12
Patent number
US07855292B2

Reaction notes

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