Hydrochloric Acid → 3-Methyl-5-(4-nitrophenoxymethyl)-1,2,4-oxadiazole
Reaction equation
[N+:1]([C:4]1[CH:14]=[CH:13][C:7]([O:8][CH2:9][C:10]([OH:12])=O)=[CH:6][CH:5]=1)([O-:3])=[O:2].Cl.C(N(CC)CC)C.[C:23](=[N:26]O)([NH2:25])[CH3:24].CCN=C=NCCCN(C)C.Cl.Cl.C(N(C(C)C)CC)(C)C>C1COCC1>[CH3:24][C:23]1[N:26]=[C:10]([CH2:9][O:8][C:7]2[CH:6]=[CH:5][C:4]([N+:1]([O-:3])=[O:2])=[CH:14][CH:13]=2)[O:12][N:25]=1Participants
Reactant 5
Product 1
Reagents, catalysts & solvents 1
Procedure
A mixture of 4-nitrophenoxyacetic acid (12) (2.25 g, 11.4 mmol), acetamide oxime triethylamine hydrochloride salt (11, 5.85 g, 27.62 mmol), EDCl.HCl (4.37 g, 22.79 mmol) and diisopropylethylamine (7.42 g, 10 mL, 57.40 mmol) in anhydrous tetrohydrofuran (THF) (250 mL) was refluxed for 18 hours. The heterogeneous brown reaction mixture was then quenched with water and extracted with EtOAc (3×300 mL). The combined organic layers were washed successively with aqueous sodium bicarbonate (NaHCO3) and brine. The resulting organic phase was dried over anhydrous Na2SO4 and solvent was removed by using rotary evaporator. The resulting residue was purified by silica gel column chromatography to yield 1.62 g (60%) of the desired product, 3-methyl-5-(4-nitrophenoxymethyl)-1,2,4-oxadiazole (13a) as a white solid. 1H NMR (CDCl3, 300 MHz): δ 8.24 (d, 2H, J=8.8 Hz), 7.08 (d, 2H, J=8.8 Hz), 5.36 (s, 2H), 2.44 (s, 3H); LCMS (m/z): 236 (MH+).
Workup
- customThe heterogeneous brown reaction mixture was then quenched with water
- extractionextracted with EtOAc (3×300 mL)
- washThe combined organic layers were washed successively with aqueous sodium bicarbonate (NaHCO3) and brine
- dry with materialThe resulting organic phase was dried over anhydrous Na2SO4 and solvent
- customwas removed
- customevaporator
- customThe resulting residue was purified by silica gel column chromatography
Sources & evidence
- ORD record
- ord-6035eb1e71a64c4d9c9c01070dc79656
- Source dataset
- uspto-grants-2013_03
- Patent number
- US08399472B2
Reaction notes
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