Triethylamine → 3,6,6-Trimethyl-1,4-dioxane-2,5-dione

Temperature

60 °C

5 g α-hydroxyisobutyric acid (48 mmol) and 5.15 mL 2-bromopropionyl chloride (50 mmol) were stirred at 75° C. under nitrogen for 12 h. 300 mL acetone and 14 mL anhydrous triethylamine (100 mmol) were added to the mixture and the solution was stirred for 3 h at 60° C. After filtration of the triethylammonium chloride salts, acetone was distilled off and the resulting mixture was dissolved in 450 mL ethyl acetate:hexane mixture (1:1). After filtration over silica gel the solvents were distilled off, and the remaining crude product was recrystallized from ethyl acetate:hexane mixture (1:10). 1H NMR (500 MHz, CDCl3): δ 5.1 (q, 1H), 1.705 (s, 6H), 1.69 (d, 3H). 13C NMR (500 MHz, CDCl3): δ 168.58, 166.64, 80.54, 72.90, 26.23, 25.27, 17.41. ELEM. ANAL. Calcd. for C7H10O4: C, 53.16; H, 6.33. Found: C, 52.86; H, 6.39. Yield: 46%.

1. filtrationAfter filtration of the triethylammonium chloride salts, acetone
2. distillationwas distilled off
3. dissolutionthe resulting mixture was dissolved in 450 mL ethyl acetate
4. filtrationAfter filtration over silica gel the solvents
5. distillationwere distilled off
6. customthe remaining crude product was recrystallized from ethyl acetate

ORD record

ord-baf80bd58e454ac9989f5e2d4a7da471

Source dataset

uspto-grants-2013_06

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08466133B2