Sodium Bicarbonate → Benzyl L-leucinate

HRID 1089824Notes

Reaction equation

HRID 1089824 reaction equation
S(C1C=CC(C)=CC=1)(O)(=O)=O.[CH2:12]([O:19][C:20](=[O:27])[C@H:21]([CH2:23][CH:24]([CH3:26])[CH3:25])[NH2:22])[C:13]1[CH:18]=[CH:17][CH:16]=[CH:15][CH:14]=1.C(=O)(O)[O-].[Na+]>C(Cl)Cl.CCCCCC.CCOC(C)=O>[CH2:12]([O:19][C:20](=[O:27])[C@H:21]([CH2:23][CH:24]([CH3:25])[CH3:26])[NH2:22])[C:13]1[CH:18]=[CH:17][CH:16]=[CH:15][CH:14]=1

Participants

6

Reactant 2

HCID 516892Sodium BicarbonateHCID 6451312L-Leucine, phenylmethyl ester, 4-methylbenzenesulfonate (1:1)

Product 1

HCID 6451313Benzyl L-leucinateYield 67.2%

Reagents, catalysts & solvents 3

HCID 6344DichloromethaneSolventHCID 8058HexaneSolvent2×HCID 8857Ethyl AcetateSolvent3×

Procedure

A solution Of L-leucine benzyl ester tosylate (5.8 g, 14.8 mmol) in 80 mL methylene chloride was stirred together with aqueous solution of saturated sodium bicarbonate (large excess) for I5 min at room temperature. The organic phase was separated, dried over magnesium sulfate and charged with 9-fluorenemethoxycarbonyl-O-succinimide (2.5 g, 7.4 mmol) at room temperature. The reaction was monitored via TLC (silica, 25% EtOAc in hexane). After two hours the reaction was over (according to its TLC with 25% EtOAc in hexane). However it was further stirred at room temperature for 48 hours. The solution was diluted with EtOAc then was washed with water (×2), 3% aqueous HCl, water (×3) and brine. The solution was dried over magnesium sulfate and evaporated. The resulting oil was crystallized from hexane:ether to yield 2.2 g (48.7%) of colorless solid, mp 91°-2° C.

Workup

  1. customThe organic phase was separated
  2. dry with materialdried over magnesium sulfate
  3. washthen was washed with water (×2), 3% aqueous HCl, water (×3) and brine
  4. dry with materialThe solution was dried over magnesium sulfate
  5. customevaporated
  6. customThe resulting oil was crystallized from hexane

Sources & evidence

ORD record
ord-924b11690e2a4119a66643c57fb075a3
Source dataset
uspto-grants-1992_01
Patent number
US05079260

Reaction notes

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