Aminoisobutyric acid → N-((Benzyloxy)carbonyl)-2-methylalanine

Participants

Reaction Steps

To a solution of 2-amino-2-methyl-propanoic acid (10 g, 96.97 mmol) in water (75 mL) was added triethylamine (13.48 mL, 96.97 mmol) followed by the dropwise addition of a solution of benzyl (2,5-dioxopyrrolidin-1-yl) carbonate (24.17 g, 96.97 mmol) in MeCN (30 mL). The pH was monitored during the addition and afterwards was adjusted with triethylamine (1.5 mL) from pH 7 to 8. The mixture was stirred at room temperature overnight. The reaction mixture was concentrated by removal of MeCN. To the aqueous was added saturated aqueous sodium bicarbonate (2 mL) which gave a suspension. This was filtered and the solid kept to one side. The filtrate was extracted with ether (three times). The aqueous phase was acidified to pH 3 with approximately 1 M aqueous potassium bisulphate and then extracted into EtOAc (three times). The combined EtOAc extracts were dried over magnesium sulphate, filtered and evaporated to yield 2-(benzyloxycarbonylamino)-2-methyl-propanoic acid (D32) as a waxy white solid, (18.001 g);

Provenance & Evidence