Ethylamine → L-Theanine

HRID 1925776

Reaction equation

HRID 1925776 reaction equation
CO[C:3]([CH2:5][CH2:6][C@H:7]([NH2:11])[C:8]([OH:10])=[O:9])=[O:4].C(CC(=O)C)(=O)C.[CH2:19]([N:21](CC)CC)[CH3:20].C(N)C>CO>[NH2:11][C@H:7]([C:8]([OH:10])=[O:9])[CH2:6][CH2:5][C:3]([NH:21][CH2:19][CH3:20])=[O:4]

Participants

6

Reactant 4

HCID 6341EthylamineHCID 8471TriethylamineHCID 31261AcetylacetoneHCID 686625-Methyl hydrogen L-glutamate

Product 1

HCID 439378L-TheanineYield 91%

Reagents, catalysts & solvents 1

HCID 887MethanolSolvent

Conditions

Temperature
60 °C

Procedure

First, 320 g (1.983 mol) of L-glutamic acid-γ-methyl ester was suspended in 500 g of methanol. To this, 219 g (2.186 mol, 1.1 eq.) of acetylacetone and 200 g (1.983 mol, 1 eq.) of triethylamine were added. The mixture was stirred at 60° C. for one hour. Subsequently, 1,277 g (19.8 mol) of 70% ethylamine was added to the mixture. After the mixture was allowed to react for 6 hours, the reaction solution was heated under normal pressure. In this manner, 667 g of excessive ethylamine was recovered and deprotection was performed at the same time. To the slurry of the theanine precipitated, 1 L of 2-propanol was added. The crystal was filtrated by suction and washed with 200 mL of 99.5% ethanol to obtain theanine (314.3 g) as a white crystal substance (yield: 91%). The obtained theanine had the same purity as high as in Example 1.

Workup

  1. customto react for 6 hours
  2. temperaturethe reaction solution was heated under normal pressure
  3. customIn this manner, 667 g of excessive ethylamine was recovered
  4. customTo the slurry of the theanine precipitated
  5. addition1 L of 2-propanol was added
  6. filtrationThe crystal was filtrated by suction
  7. washwashed with 200 mL of 99.5% ethanol

Sources & evidence

ORD record
ord-d01eb78e7f554425aa2459a45789765c
Source dataset
uspto-grants-2012_05
Patent number
US08178722B2

Linked notes

Loading…