Ethanolamine → Benzoic acid, 3-(6-amino-3-methyl-2-pyridinyl)-, 1,1-dimethylethyl ester

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

A solution of 2-(3-(tert-butoxycarbonyl)phenyl)-3-methylpyridine-1-oxide (1 eq) and pyridine (4 eq) in MeCN (8 vol) is heated to 70° C. A solution of methanesulfonic anhydride (1.5 eq) in MeCN (2 vol) is added over 50 min via addition funnel maintaining the temperature at less than 75° C. The mixture is stirred for an additional 0.5 hours after complete addition. The mixture is then allowed to cool to ambient. Ethanolamine (10 eq) is added via addition funnel. After stirring for 2 hours, water (6 vol) is added and the mixture is cooled to 10° C. After stirring for NLT 3 hours, the solid is collected by filtration and washed with water (3 vol), 2:1 MeCN/water (3 vol), and MeCN (2×1.5 vol). The solid is dried to constant weight (<1% difference) in a vacuum oven at 50° C. with a slight N2 bleed to afford tert-butyl-3-(6-amino-3-methylpyridin-2-yl)benzoate as a red-yellow solid (53% yield).

Herkunft & Nachweise