Citric Acid → HCID 53804967, compound

HRID 1262886Notes

Reaction equation

HRID 1262886 reaction equation
[C:1]([O:5][C:6]([NH:8][C@@H:9]([C:14]([OH:16])=[O:15])[CH2:10][CH2:11][S:12][CH3:13])=[O:7])([CH3:4])([CH3:3])[CH3:2].[H-].[K+].[CH2:19]1OCCOCCOCCOCCOCCOC1.CI.C(O)(=O)CC(CC(O)=O)(C(O)=O)O>O1CCCC1>[C:1]([O:5][C:6]([N:8]([CH3:19])[C@@H:9]([C:14]([OH:16])=[O:15])[CH2:10][CH2:11][S:12][CH3:13])=[O:7])([CH3:4])([CH3:2])[CH3:3]

Participants

7

Reactant 5

HCID 311Citric AcidHCID 6328Methyl iodideHCID 2855718-Crown-6HCID 82127Potassium hydrideHCID 111051N-(tert-Butyloxycarbonyl)-D-methionine

Product 1

HCID 53804967HCID 53804967, compound

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent2×

Procedure

A solution of N-(tert-butyloxycarbonyl)-D-methionine (20 g.) in tetrahydrofuran was added dropwise with stirring to a suspension of potassium hydride (35% in mineral oil, 27.5 g.) in tetrahydrofuran (160 ml.) containing 18-crown-6 ether (1 g.) maintained at ice bath temperature. Stirring was continued for one and one quarter hours. Methyl iodide (5 ml.) was added, stirring was continued, and the temperature was allowed to rise to room temperature during 22 hours. The pH was adjusted to 3 with aqueous citric acid (1 M) with cooling. The mixture was partitioned between ether and water. The ether layer was extracted with aqueous sodium bicarbonate. The aqueous sodium bicarbonate layer was extracted with ether. The latter ether layer was washed with water, dried and stripped of ether, affording N-(tert-butyloxycarbonyl)-N-methyl-D-methionine as a syrup (15.5 g.).

Workup

  1. temperaturemaintained at ice bath temperature
  2. waitwas continued for one and one quarter hours
  3. stirringstirring
  4. temperaturewith cooling
  5. customThe mixture was partitioned between ether and water
  6. extractionThe ether layer was extracted with aqueous sodium bicarbonate
  7. extractionThe aqueous sodium bicarbonate layer was extracted with ether
  8. washThe latter ether layer was washed with water
  9. customdried

Sources & evidence

ORD record
ord-f833e17117bb4c0c9783ca744b3b9891
Source dataset
uspto-grants-1984_06
Patent number
US04454120

Reaction notes

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