Oxalic Acid → HCID 22996352, compound

Temperature

0 °C

A freshly prepared solution of lithium diisopropylamide, was generated by the addition of n-butyllithium (16.2 mL, 25.9 mmol, 1.6 M in hexane) to a solution of diisopropylamine (6.6 mL, 47.0 mmol) in tetrahydrofuran (20 mL) at −20° C., and allowed to warm to 0° C. and stir for 30 minutes. N-(2-methylpropylidene)-2-methyl-2-propanamine (3.0 g, 23.5 mmol) in tetrahydrofuran (10 mL) was added dropwise over 10 minutes. After stirring at 0° C. for 2 hours, 2-bromoethyl-2-methyl-1,3-dioxolane (5.0 g, 25.9 mmol) in tetrahydrofuran (10 mL) was added over 15 minutes. The reaction was allowed to warm to ambient temperature and stirring was continued for 16 hours. After cooling in an ice bath, an aqueous solution of oxalic acid (100 mL, 10 wgt %) was added and reaction stirred for 1 hour. The layers were separated and the aqueous was extracted with ether (100 mL). The combined organic layers were washed with brine (50 mL), saturated sodium bicarbonate/water (50 mL), brine (50 mL), dried (magnesium sulfate), concentrated in vacuo and chromatographed (silica gel, ethyl acetate/hexane, 1:9) to afford the title compound (1.0 g, 23%) as a clear liquid;

1. stirringAfter stirring at 0° C. for 2 hours
2. temperatureto warm to ambient temperature
3. stirringstirring
4. waitwas continued for 16 hours
5. temperatureAfter cooling in an ice bath
6. customreaction
7. stirringstirred for 1 hour
8. customThe layers were separated
9. extractionthe aqueous was extracted with ether (100 mL)
10. washThe combined organic layers were washed with brine (50 mL), saturated sodium bicarbonate/water (50 mL), brine (50 mL)
11. dry with materialdried (magnesium sulfate)
12. concentrationconcentrated in vacuo
13. customchromatographed (silica gel, ethyl acetate/hexane, 1:9)

ORD record

ord-3641e435c8f44b889e7e5ff35cc1a6b4

Source dataset

uspto-grants-2003_09

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06617350B2