(4-Nitrophenoxy)acetic acid → 3-Methyl-5-(4-nitrophenoxymethyl)-1,2,4-oxadiazole

HRID 1962220Notes

Reaction equation

HRID 1962220 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.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]=1

Participants

6

Reactant 4

HCID 15720(4-Nitrophenoxy)acetic acidHCID 81531DiisopropylethylamineHCID 27239391,3-Propanediamine, N'-(ethylcarbonimidoyl)-N,N-dimethyl-, monohydrochlorideHCID 86609722HCID 86609722, compound

Product 1

HCID 220604453-Methyl-5-(4-nitrophenoxymethyl)-1,2,4-oxadiazoleYield 60.4%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent

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), EDCI.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

  1. temperaturewas refluxed for 18 hours
  2. customThe heterogeneous brown reaction mixture was then quenched with water
  3. extractionextracted with EtOAc (3×300 mL)
  4. washThe combined organic layers were washed successively with aqueous sodium bicarbonate (NaHCO3) and brine
  5. dry with materialThe resulting organic phase was dried over anhydrous Na2SO4 and solvent
  6. customwas removed
  7. customevaporator
  8. customThe resulting residue was purified by silica gel column chromatography

Sources & evidence

ORD record
ord-96c62c2774bc4652a29b1e951a9c417c
Source dataset
uspto-grants-2013_04
Patent number
US08415365B2

Reaction notes

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