Dabco → Ethyl 5-cyclopropylisoxazole-3-carboxylate

HRID 58531

Reaction equation

HRID 58531 reaction equation
[C:1]([CH:3]1[CH2:5][CH2:4]1)#[CH:2].[N+:6]([CH2:9][C:10]([O:12][CH2:13][CH3:14])=[O:11])([O-])=[O:7].C1N2CCN(CC2)C1>C(O)C>[CH:3]1([C:1]2[O:7][N:6]=[C:9]([C:10]([O:12][CH2:13][CH3:14])=[O:11])[CH:2]=2)[CH2:5][CH2:4]1

Participants

5

Reactant 3

HCID 9237DabcoHCID 69379Ethyl nitroacetateHCID 138823Cyclopropylacetylene

Product 1

HCID 55251041Ethyl 5-cyclopropylisoxazole-3-carboxylateYield 92.2%

Reagents, catalysts & solvents 1

HCID 702EthanolSolvent

Procedure

A solution of ethynylcyclopropane (0.40 mL; 4.58 mmol), ethyl 2-nitroacetate (1.30 mL; 11.46 mmol), and 1,4-diazobicyclo[2.2.2]octane (DABCO, 0.053 g; 0.458 mmol) in ethanol (3 mL) was irradiated in a microwave oven at 150° C. for 20 min and was then evaporated. The residue was dissolved in ethyl acetate and the solution was washed with water. The organic layer was evaporated and the residue was purified by flash chromatography on silica gel (eluent: 20 to 100% of dichloromethane in heptane) to afford 0.765 g (92%) of ethyl 5-cyclopropylisoxazole-3-carboxylate as a yellow oil.

Workup

  1. customwas then evaporated
  2. dissolutionThe residue was dissolved in ethyl acetate
  3. washthe solution was washed with water
  4. customThe organic layer was evaporated
  5. customthe residue was purified by flash chromatography on silica gel (eluent: 20 to 100% of dichloromethane in heptane)

Sources & evidence

ORD record
ord-9e524bd03fb64855931146cbd86ab99c
Source dataset
uspto-grants-2016_09
Patent number
US09434722B2

Linked notes

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