Reacción #640536

Ecuación de reacción

N-4-methoxybenzyloxycarbonyl α-methyl β-alanine methyl ester

lithium hydroxide

→

N-4-Methoxybenzyloxycarbonyl α-methyl β-alanine

Rendimiento 97.3%

Disolventes

methanol

Condiciones de reacción

Tratamiento posterior

1. 1
   ConcentraciónThe solution was concentrated in vacuo
2. 2
   workup.ADDITIONthe residue taken up in a mixture of water and ether
3. 3
   Otrothe phases separated
4. 4
   Extracciónextracted three times with ether
5. 5
   LavadoThe combined ethereal phase was washed with saturated aqueous sodium chloride solution
6. 6
   Secadodried over anhydrous magnesium sulfate
7. 7
   Filtraciónfiltered
8. 8
   Concentraciónconcentrated in vacuo

Procedimiento

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=7.2Hz), 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).

Fuente