Hydrochloric Acid → HCID 54281127, compound

HRID 1462940Notes

Reaction equation

HRID 1462940 reaction equation
[CH3:1][O:2][C:3]1[CH:11]=[CH:10][C:6]([C:7](Cl)=[O:8])=[CH:5][CH:4]=1.[NH2:12][CH2:13][CH2:14][C@@H:15]([OH:19])[C:16]([OH:18])=[O:17].[OH-].[Na+].Cl>O>[CH3:1][O:2][C:3]1[CH:11]=[CH:10][C:6]([C:7]([NH:12][CH2:13][CH2:14][C@@H:15]([OH:19])[C:16]([OH:18])=[O:17])=[O:8])=[CH:5][CH:4]=1

Participants

6

Reactant 4

HCID 313Hydrochloric AcidHCID 7477p-Anisoyl chlorideHCID 14798Sodium HydroxideHCID 5287507(2R)-4-AMINO-2-HYDROXYBUTYRIC ACID

Product 1

HCID 54281127HCID 54281127, compound

Reagents, catalysts & solvents 1

HCID 962WaterSolvent

Procedure

17.2 g of p-methoxybenzoyl chloride are added while stirring well to 6.0 g of (R)-4-amino-2-hydroxy-butyric acid and 150 ml of ion-free water. The mixture is then adjusted to pH 10.5 with 2 N sodium hydroxide and stirred at room temperature for 70 minutes. The clear solution is treated with ice and adjusted to pH 1.4 with 25% hydrochloric acid. The separated solid is filtered off and washed with water. The filtrate is adjusted to pH 5.5 with sodium hydroxide and concentrated in a water-jet vacuum. The clear colourless solution is adjusted to pH 1.4 with 25% hydrochloric acid and extracted firstly with ether and then with ethyl acetate. The aqueous phases are adjusted to pH 5.5, concentrated, acidified with 25% hydrochloric acid and extracted with ethyl acetate. The combined ethyl acetate extracts are evaporated and the residue is recrystallised from ethyl acetate. There is obtained (R)-4-(p-methoxybenzoylamino)-2-hydroxy-butyric acid of melting point 105°-106° C.; [α]D20 = -12.4°; [α]36520 =-60.5° (c=1.0 in water). A further amount of (R)-4-(p-methoxybenzoylamino)-2-hydroxy-butyric acid of melting point 103.5°-104.5° C. can be isolated from the mother liquors.

Workup

  1. additionThe clear solution is treated with ice
  2. filtrationThe separated solid is filtered off
  3. washwashed with water
  4. concentrationconcentrated in a water-jet vacuum
  5. extractionextracted firstly with ether
  6. concentrationconcentrated
  7. extractionextracted with ethyl acetate
  8. customThe combined ethyl acetate extracts are evaporated
  9. customthe residue is recrystallised from ethyl acetate

Sources & evidence

ORD record
ord-d2a39b71d08545c1af68f34e9d04fdf6
Source dataset
uspto-grants-1984_07
Patent number
US04461906

Reaction notes

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