Triethylamine → 3-Methyl-6-isopropyl-1,4-dioxane-2,5-dione
Reaction equation
[OH:1][CH:2]([CH:6]([CH3:8])[CH3:7])[C:3]([OH:5])=[O:4].Br[CH:10]([CH3:14])[C:11](Br)=[O:12].C(N(CC)CC)C>CC(C)=O>[CH3:14][CH:10]1[O:4][C:3](=[O:5])[CH:2]([CH:6]([CH3:8])[CH3:7])[O:1][C:11]1=[O:12]Participants
Reactant 3
Product 1
Reagents, catalysts & solvents 1
Conditions
- Temperature
- 60 °C
Procedure
5.1 g α-hydroxyisovaleric acid (43 mmol) and 4.85 mL 2-bromopropionyl bromide (45 mmol) were stirred at 75° C. under nitrogen for 12 h. 300 mL acetone and 12 mL anhydrous triethylamine (86 mmol) were added to the mixture and the solution was stirred for 3 h at 60° C. After filtration of the triethylammonium bromide salts, acetone was distilled off and the resulting mixture was dissolved in 500 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 hexane. 1H NMR (500 MHz, CDCl3): δ 5.0 (q, 1H), 4.76 (d, 1H), 2.5 (m, 1H), 1.66 (d, 3H), 1.16 (d, 3H), 1.06 (d, 3H). 13C NMR (500 MHz, CDCl3): δ 167.59, 166.16, 79.83, 72.10, 29.24, 18.51, 15.86, 15.79. ELEM. ANAL. Calcd. for C8H12O4: C, 55.81; H, 6.98. Found: C, 55.55; H, 6.99. Yield: 35%.
Workup
- filtrationAfter filtration of the triethylammonium bromide salts, acetone
- distillationwas distilled off
- dissolutionthe resulting mixture was dissolved in 500 mL ethyl acetate
- filtrationAfter filtration over silica gel the solvents
- distillationwere distilled off
- customthe remaining crude product was recrystallized from hexane
Sources & evidence
- ORD record
- ord-a7bc8c61a1e744a281d91892d59ad83c
- Source dataset
- uspto-grants-2014_06
- Patent number
- US08741877B2
Reaction notes
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