Diethyl Oxalate → 4-(2-Hydroxyethyl)-2,3-morpholinedione

Temperature

22 °C

A 4(2-hydroxyethyl)morpholine-2,3-dione was prepared by charging 125 g diethyl oxalate and 80 g n-butanol into a suitable reaction vessel and heated to 22° C. under nitrogen blanket. A mixture of 89.9 g diethanolamine and 72 g n-butanol was slowly charged into the reaction vessel while maintaining the reaction mixture below 50° C. After stirring for 30 minutes, the reaction mixture was refluxed for one hour and then allowed to stand at room temperature for 16 hours. The product was collected by filtration and the solid was washed twice with diethyl ether and dried under nitrogen to give 100 g (73.4% yield) of white crystals with 83.3° C.-84.4° C. melting point. IR (Nujol mull) 1759 (ester carbonyl), 1684 (amide carbonyl) cm−1. 1H NMR (500 MHz, acetone-d6) δ 4.592 (approx. triplet, 2H, J=5.0 Hz, ring CH2O), 3.903 (approx. triplet, 2H, J=5.0 Hz, ring CH2N), 3.767 (t, 2H, J=5.5 Hz, CH2OH), 3.597 (t, 2H, J=5.5 Hz, chain CH2N). 13C NMR (500 MHz, D2O) δ158.514 (ester C═O), 155.338 (amide C═O), 67.036 (ring CH2O), 60.399 (CH2OH), 51.034 (ring CH2N), 47.600 (chain CH2N).

1. additionwas slowly charged into the reaction vessel
2. temperaturewhile maintaining the reaction mixture below 50° C
3. temperaturethe reaction mixture was refluxed for one hour
4. waitto stand at room temperature for 16 hours
5. filtrationThe product was collected by filtration
6. washthe solid was washed twice with diethyl ether
7. customdried under nitrogen

ORD record

ord-599456f2ef62479180ea929a413ad031

Source dataset

uspto-grants-2005_06

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06908539B2