Methanol → Dibenzyl L-aspartate

HRID 49646Notes

Reaction equation

HRID 49646 reaction equation
C1(C)C=CC(S(O)(=O)=O)=CC=1.[NH2:12][C@H:13]([C:25]([O:27][CH2:28][C:29]1[CH:34]=[CH:33][CH:32]=[CH:31][CH:30]=1)=[O:26])[CH2:14][C:15]([O:17][CH2:18][C:19]1[CH:24]=[CH:23][CH:22]=[CH:21][CH:20]=1)=[O:16].[OH-].[Na+].P(=O)(O)(O)O.CO>C(Cl)(Cl)Cl>[NH2:12][C@H:13]([C:25]([O:27][CH2:28][C:29]1[CH:30]=[CH:31][CH:32]=[CH:33][CH:34]=1)=[O:26])[CH2:14][C:15]([O:17][CH2:18][C:19]1[CH:24]=[CH:23][CH:22]=[CH:21][CH:20]=1)=[O:16]

Participants

6

Reactant 4

HCID 887MethanolHCID 1004Phosphoric AcidHCID 14798Sodium HydroxideHCID 2808531L-Aspartic acid, 1,4-bis(phenylmethyl) ester, 4-methylbenzenesulfonate (1:1)2×

Product 1

HCID 2808532Dibenzyl L-aspartate

Reagents, catalysts & solvents 1

HCID 6212ChloroformSolvent2×

Procedure

19.4 g of the thus-obtained dibenzyl L-aspartate paratoluenesulfonate was suspended in 150 ml of chloroform, to which was added 16 g (0.04 mols) of aqueous 10% sodium hydroxide solution, and stirred at room temperature for 1 hour. Next, the chloroform layer was separated, to which was added 14.7 g (0.04 mols) of O,O′-diparatoluoyl-L-tartaric anhydride, and again stirred at room temperature for 2 hours. The chloroform layer was analyzed through HPLC. Its chart gave two peaks based on O,O′-diparatoluoyl-L-tartaric acid mono-L-(1,2-dibenzyloxycarbonyl)ethylamide (L-L form) of formula (16) and on O,O′-diparatoluoyl-L-tartaric acid mono-D-(1,2-dibenzyloxycarbonyl)ethylamide (L-D form) of formula (17), and the optical purity of the dibenzyl L-aspartate paratoluenesulfonate used in the reaction was found to be 59.0% ee (FIG. 1—column, CAPCELL PAC SG120; eluent, aqueous phosphoric acid solution (pH 2.2)/methanol=38/62 v/v).

Workup

  1. customNext, the chloroform layer was separated, to which
  2. stirringagain stirred at room temperature for 2 hours
  3. customIts chart gave two peaks

Sources & evidence

ORD record
ord-9f60f315702d478dbb8a006f304eeacd
Source dataset
uspto-grants-2004_03
Patent number
US06706916B1

Reaction notes

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