Hydrochloric Acid → L-Leucine ethyl ester

HRID 1857683Notes

Reaction equation

HRID 1857683 reaction equation
C(Cl)(=O)C(Cl)=O.Cl.[CH2:8]([O:10][C:11](=[O:18])[C@H:12]([CH2:14][CH:15]([CH3:17])[CH3:16])[NH2:13])[CH3:9].Cl>C1(C)C=CC=CC=1.N1C=CC=CC=1.ClCCl.CO>[CH2:8]([O:10][C:11](=[O:18])[C@H:12]([CH2:14][CH:15]([CH3:17])[CH3:16])[NH2:13])[CH3:9]

Participants

7

Reactant 3

HCID 313Hydrochloric AcidHCID 65578Oxalyl chlorideHCID 11658447L-Leucine, ethyl ester, hydrochloride (1:1)

Product 1

HCID 75971L-Leucine ethyl esterYield 66%

Reagents, catalysts & solvents 3

HCID 1049PyridineSolvent2×HCID 1140TolueneSolvent3×HCID 21226129Dichloromethane methanolSolvent

Conditions

Temperature
10 °C

Procedure

2.14 g (6.77 mmoles) of compound (I) are dissolved in anhydrous toluene (34 ml) and pyridine (0.75 ml). The reaction is cooled to a temperature of 10° C. and, under vigorous stirring, a solution of oxalyl chloride (0.728 ml) in toluene (2 ml) is added. The reaction is maintained under stirring at a temperature of 10° C. for 1 hour. Then a suspension of L-leucine ethyl ester hydrochloride (6.6 g, 33.8 mmoles) in toluene (6 ml) and pyridine (2.71 ml) is added. The reaction is heated at a temperature of 40° C. for 4 hours, with vigorous stirring. After that ice (40 g) is added and the reaction pH is adjusted to 2 con 1N HCl, the organic phase is separated and the aqueous phase is extracted with dichloromethane (3×50 ml). The combined organic phases are then dried over sodium sulfate and evaporated under vacuum to give a crude, which is subsequently purified by silica gel chromatography (dichloromethane/methanol 9/1) 2.03 g (4.44 mmoles) of compound (II) are obtained, wherein Y=--CH(Q)--T is the residue of L-leucine ethyl ester, (66% yield).

Workup

  1. temperatureThe reaction is maintained
  2. additionis added
  3. temperatureThe reaction is heated at a temperature of 40° C. for 4 hours, with vigorous stirring
  4. customthe organic phase is separated
  5. extractionthe aqueous phase is extracted with dichloromethane (3×50 ml)
  6. dry with materialThe combined organic phases are then dried over sodium sulfate
  7. customevaporated under vacuum
  8. customto give a crude, which
  9. customare obtained

Sources & evidence

ORD record
ord-0124c1386c184882810a174e0328de61
Source dataset
uspto-grants-2000_11
Patent number
US06147213

Reaction notes

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