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

HRID 1450668Notes

Reaction equation

HRID 1450668 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 h. 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-cdd919b4fb624dc9a87df933b2cd51c4
Source dataset
uspto-grants-1997_02
Patent number
US05602175

Reaction notes

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