Triethylamine → N-(2,6-Diisopropyl-phenyl)-malonamic acid ethyl ester

Participants

Reaction Conditions

Reaction Steps

A 5 L 4-necked flask was fitted with a mechanical stirrer and temperature probe and then purged with nitrogen. The flask was charged with 200 mL (188 g, 1.06 mol) of 2,6-diisopropyl aniline, 163 mL (118 g, 1.17 mol) of triethylamine and 2.5 L of ethyl acetate. The clear, yellow solution was cooled to 0° C. with stirring and 143 mL (168 g, 95% pure, 1.06 mol) of ethyl malonyl chloride was added over 15 min. The internal temperature rose as high as 22° C. during the addition. The cold bath was removed and the yellow suspension was stirred for 100 min (HPLC indicated reaction completion). The suspension was filtered and the filtrate was evaporated at the Rotavap giving yellowish solids. The crude ester were then recrystallized from 3.0 L of heptane yielding 240.24 g (78%) of N-(2,6-Diisopropyl-phenyl)-malonamic acid ethyl ester as slightly yellow solids. HPLC analysis indicated >99% (a/a) purity. The materials 1H-NMR spectrum was consistent with structure

Provenance & Evidence