Ethylene Glycol → Ethyl 5-(2-methyl-1,3-dioxolan-2-yl)isoxazole-3-carboxylate

HRID 416274Notes

Reaction equation

HRID 416274 reaction equation
[C:1]([C:4]1[O:8][N:7]=[C:6]([C:9]([O:11][CH2:12][CH3:13])=[O:10])[CH:5]=1)(=[O:3])[CH3:2].[CH2:14](O)[CH2:15][OH:16]>C1C=CC=CC=1.CC1C=CC(S(O)(=O)=O)=CC=1>[CH3:2][C:1]1([C:4]2[O:8][N:7]=[C:6]([C:9]([O:11][CH2:12][CH3:13])=[O:10])[CH:5]=2)[O:16][CH2:15][CH2:14][O:3]1

Participants

5

Reactant 2

HCID 174Ethylene GlycolHCID 27363535-Acetyl-isoxazole-3-carboxylic acid ethyl ester

Product 1

HCID 58930452Ethyl 5-(2-methyl-1,3-dioxolan-2-yl)isoxazole-3-carboxylateYield 100.1%

Reagents, catalysts & solvents 2

HCID 6101p-Toluenesulfonic acidCatalystHCID 241BenzeneSolvent

Procedure

A reaction mixture consisting of ethyl 5-acetylisoxazole-3-carboxylate (2.53 g, 13.8 mmol), ethylene glycol (1.29 g, 20.7 mmol) and p-TsOH (0.13 g, 0.69 mmol) in benzene (50 mL) was refluxed with the Dean-Stark adapter for 24 hours (scheme 59). Most of the solvent was removed under reduced pressure and the residue was partitioned between saturated NaHCO3 and EtOAc. Organic layer was collected, washed with brine, water, and dried over MgSO4. Evaporation of the dried extract under reduced pressure afforded the title compound as an oil (3.14 g, 100% yield), which was used for next step without further purification. 1H NMR (DMSO-d6) δ (ppm): 6.89 (s, 1H), 4.35 (q, J=7.2 Hz, 2H), 4.07-4.01 (m, 2H), 4.01-3.94 (m, 2H), 1.70 (s, 3H), 1.32 (t, J=7.0 Hz, 3H). MS (m/z): 227.21 (calc) 228.1 (MH+) (found).

Workup

  1. temperaturewas refluxed with the Dean-Stark adapter for 24 hours (scheme 59)
  2. customMost of the solvent was removed under reduced pressure
  3. customthe residue was partitioned between saturated NaHCO3 and EtOAc
  4. customOrganic layer was collected
  5. washwashed with brine, water
  6. dry with materialdried over MgSO4
  7. customEvaporation of the dried
  8. extractionextract under reduced pressure

Sources & evidence

ORD record
ord-f6bfd3162b91455da114214aad23ba38
Source dataset
uspto-grants-2012_01
Patent number
US08088805B2

Reaction notes

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