Hydrochloric Acid → Tyrosine ethyl ester hydrochloride

HRID 1378456Notes

Reaction equation

HRID 1378456 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.[ClH:14].[CH2:15](O)[CH3:16]>>[ClH:14].[CH2:15]([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])[CH3:16]

Participants

4

Reactant 3

HCID 313Hydrochloric Acid2×HCID 702EthanolHCID 6057L-Tyrosine

Product 1

HCID 2724939Tyrosine ethyl ester hydrochloride

Procedure

L-Tyrosine (1.00 kg, 5.52 mol) is suspended in 2B anhydrous ethanol (5.0 L). Anhydrous hydrogen chloride is introduced into this suspension initially at ambient temperature for 2.5 hours at which time the temperature rises to 56° C. The resulting clear solution is refluxed for 5 hours with continued introduction of a slow stream of hydrogen chloride. The solution is allowed to cool overnight and completion of precipitation of product is induced by the addition of t-butyl methyl ether (12.0 L). The crystals are collected by filtration and the filtrate is washed with more t-butyl methyl ether (2×500 mL). The solid is first air-dried and then vacuum-dried for 36 hours (40° C., 3.Torr) to yield L-tyrosine ethyl ester monohydrochloride, m.p. 165°-166° C.

Workup

  1. customrises to 56° C
  2. temperatureto cool overnight
  3. customcompletion of precipitation of product
  4. additionis induced by the addition of t-butyl methyl ether (12.0 L)
  5. filtrationThe crystals are collected by filtration
  6. washthe filtrate is washed with more t-butyl methyl ether (2×500 mL)
  7. customThe solid is first air-dried
  8. customvacuum-dried for 36 hours (40° C., 3.Torr)

Sources & evidence

ORD record
ord-147a2a02def648d5b0ddd0468c3b957b
Source dataset
uspto-grants-1997_09
Patent number
US05668158

Reaction notes

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