Methanol → Methyl tyrosinate hydrochloride

HRID 916898Notes

Reaction equation

HRID 916898 reaction equation
[NH2:1][C@H:2]([C:11]([OH:13])=[O:12])[CH2:3][C:4]1[CH:9]=[CH:8][C:7]([OH:10])=[CH:6][CH:5]=1.S(Cl)([Cl:16])=O.[CH3:18]O>>[ClH:16].[CH3:18][O:12][C:11](=[O:13])[C@H:2]([CH2:3][C:4]1[CH:5]=[CH:6][C:7]([OH:10])=[CH:8][CH:9]=1)[NH2:1]

Participants

4

Reactant 3

HCID 887MethanolHCID 6057L-TyrosineHCID 24386Thionyl Chloride

Product 1

HCID 76956Methyl tyrosinate hydrochlorideYield 90.1%

Procedure

L-tyrosine 1 (181.2 g, 1.0 mol) was suspended in methanol (1268 g), and thionyl chloride (428.3 g, 3.6 mol) was added dropwise thereto at 40° C. over 2 hrs. After further keeping at 40° C. for 3 hrs, the reaction mass was concentrated to about one third of the volume under reduced pressure. To the concentrate mass was added dropwise toluene (1268 g) at 40° C. over 1.5 hrs. After keeping at 0° C. for 1 hr, precipitates were filtered and dried under reduced pressure to give L-tyrosine methyl ester hydrochloride 2 (208.7 g, yield 90.1%) as white crystals.

Workup

  1. waitAfter further keeping at 40° C. for 3 hrs
  2. concentrationthe reaction mass was concentrated to about one third of the volume under reduced pressure
  3. additionTo the concentrate mass was added dropwise toluene (1268 g) at 40° C. over 1.5 hrs
  4. waitAfter keeping at 0° C. for 1 hr
  5. customprecipitates
  6. filtrationwere filtered
  7. customdried under reduced pressure

Sources & evidence

ORD record
ord-f8b9bf2a48f849fc9e39a102bfc49ea9
Source dataset
uspto-grants-2007_09
Patent number
US07271280B2

Reaction notes

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