Oxalic Acid → 28419-86-5

Temperature

-65 °C

To a solution of diisopropylamine (40.5 g) in tetrahydrofuran (160 ml) at -10° C. was added a solution of n-butyllithium (1.66M in hexane solution, 241 ml) under nitrogen atmosphere. The mixture was stirred for 20 minutes and then 1-(N-tert-butyl)butylimine (50.9 g) was added at the same temperature. Stirring was continued for 20 minutes and then cooled to -65° C. A solution of isobutanal (28.8 g) in tetrahydrofuran (120 ml) was added to the solution. The reaction mixture was kept at -65° C. for 90 minutes, then warmed slowly to room temperature and stirred overnight. The resultant mixture was poured into a saturated aqueous oxalic acid solution (1.5 l) and the mixture was stirred for one hour. The organic layer was separated and the aqueous layer was extracted with ethyl acetate 1300 ml×2). The combined organic layers were washed with brine, dried over anhydrous magnesium sulfate and evaporated in vacuo. The residue was distilled to give (E)-2-ethyl-4-methyl-2-pentenal (35.7 g): bP 30°~55° C. at 1.0~10 mmHg.

1. stirringStirring
2. waitwas continued for 20 minutes
3. waitThe reaction mixture was kept at -65° C. for 90 minutes
4. temperaturewarmed slowly to room temperature
5. stirringstirred overnight
6. stirringthe mixture was stirred for one hour
7. customThe organic layer was separated
8. extractionthe aqueous layer was extracted with ethyl acetate 1300 ml×2)
9. washThe combined organic layers were washed with brine
10. dry with materialdried over anhydrous magnesium sulfate
11. customevaporated in vacuo
12. distillationThe residue was distilled

ORD record

ord-6f56fe55546341c0808db6624583a872

Source dataset

uspto-grants-1997_11

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US05691366