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

HRID 400351

Reaction equation

[OH:1][CH:2]([CH2:6][CH2:7][CH2:8][CH3:9])[C:3]([OH:5])=[O:4].Br[CH:11]([CH3:15])[C:12](Br)=[O:13].C(N(CC)CC)C>CC(C)=O>[CH3:15][CH:11]1[O:4][C:3](=[O:5])[CH:2]([CH2:6][CH2:7][CH2:8][CH3:9])[O:1][C:12]1=[O:13]

Participants

Conditions

Temperature: 60 °C

Procedure

2.5 g 2-hydroxyhexanoic acid (18.9 mmol) and 2.1 mL 2-bromopropionyl bromide (19.7 mmol) were stirred at 75° C. under nitrogen for 12 h. 150 mL acetone and 5.3 mL anhydrous triethylamine (38 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 300 mL ethyl acetate:hexane mixture (1:2). 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 5.05 (q, 1H), 4.90 (dd, 1H), 1.9-2.15 (br m, 2H), 1.68 (d), 1.65 (d), (3H, of 2 diastereoisomers), 1.3-1.6 (br m, 4H), 0.93 (t, 3H). 13C NMR (500 MHz, CDCl3): δ 167.54, 166.93, 166.25, 165.85, 75.79, 72.50, 72.24, 31.61, 29.70, 26.69, 26.42, 22.19, 21.97, 17.52, 15.81, 13.72, 13.66. ELEM. ANAL. Calcd. for C9H14O4: C, 58.06; H, 7.53. Found: C, 57.62; H, 7.60. Yield: 40%.

Workup

filtrationAfter filtration of the triethylammonium bromide salts, acetone
distillationwas distilled off
dissolutionthe resulting mixture was dissolved in 300 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-ffa9a22035594fc392a93a72435f3cca
Source dataset: uspto-grants-2014_06
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US08741877B2

Linked notes

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