Lithium Hydroxide → n-4-Methoxybenzyloxycarbonyl alpha-methyl beta-alanine

HRID 1795099Notes

Reaction equation

HRID 1795099 reaction equation
C[O:2][C:3](=[O:20])[CH:4]([CH3:19])[CH2:5][NH:6][C:7]([O:9][CH2:10][C:11]1[CH:16]=[CH:15][C:14]([O:17][CH3:18])=[CH:13][CH:12]=1)=[O:8].[OH-].[Li+]>CO>[CH3:18][O:17][C:14]1[CH:13]=[CH:12][C:11]([CH2:10][O:9][C:7]([NH:6][CH2:5][CH:4]([CH3:19])[C:3]([OH:20])=[O:2])=[O:8])=[CH:16][CH:15]=1

Participants

4

Reactant 2

HCID 3939Lithium HydroxideHCID 21879751n-4-Methoxybenzyloxycarbonyl alpha-methyl beta-alanine methyl ester

Product 1

HCID 15487221n-4-Methoxybenzyloxycarbonyl alpha-methyl beta-alanineYield 97.3%

Reagents, catalysts & solvents 1

HCID 887MethanolSolvent

Procedure

A solution of N-4-methoxybenzyloxycarbonyl-α-methyl-β-alanine methyl ester (2.81 g, 10.0 mmol) in 30 mL of 25% aqueous methanol was treated with lithium hydroxide (1.3 equivalents) at room temperature for a period of 2 hours. The solution was concentrated in vacuo and the residue taken up in a mixture of water and ether and the phases separated and the organic phase discarded. The aqueous phase was acidified with aqueous potassium hydrogen sulfate to pH=1.5 and then extracted three times with ether. The combined-ethereal phase was washed with saturated aqueous sodium chloride solution, dried over anhydrous magnesium sulfate, filtered and concentrated in vacuo to give 2.60 g, 97% of N-4-methoxybenzyloxycarbonyl-α-methyl-β-alanine (N-Moz-AMBA) which was purified by recrystallization from a mixture of ethyl acetate and hexane to give 2.44 g, 91%, of pure product, mp 96–97° C., MH+=268. 1H NMR (D6-acetone/300 MHz) 1.16 (3H, d, J=7.2 Hz), 2.70 (1H, m), 3.31 (2H, m), 3.31 (3H, s), 4.99 (2H, s), 6.92 (2H, 4, J=8.7 Hz), 7.13 (2H, d, J=8.7 Hz).

Workup

  1. concentrationThe solution was concentrated in vacuo
  2. additionthe residue taken up in a mixture of water and ether
  3. customthe phases separated
  4. extractionextracted three times with ether
  5. washThe combined-ethereal phase was washed with saturated aqueous sodium chloride solution
  6. dry with materialdried over anhydrous magnesium sulfate
  7. filtrationfiltered
  8. concentrationconcentrated in vacuo

Sources & evidence

ORD record
ord-4d46ee56e1f04beba4d7d5851f5c98d5
Source dataset
uspto-grants-2006_04
Patent number
US07026333B1

Reaction notes

Loading…