Nitric Acid → 4-(5-Nitro-thiophen-2-yl)-butyric acid methyl ester

HRID 1611491

Reaction equation

HRID 1611491 reaction equation
[N+:1]([O-:4])(O)=[O:2].[CH3:5][O:6][C:7](=[O:16])[CH2:8][CH2:9][CH2:10][C:11]1[S:12][CH:13]=[CH:14][CH:15]=1>C(OC(=O)C)(=O)C>[CH3:5][O:6][C:7](=[O:16])[CH2:8][CH2:9][CH2:10][C:11]1[S:12][C:13]([N+:1]([O-:4])=[O:2])=[CH:14][CH:15]=1

Participants

4

Reactant 2

HCID 944Nitric AcidHCID 1407664-(2-Thienyl)butanoic acid methyl ester

Product 1

HCID 692334004-(5-Nitro-thiophen-2-yl)-butyric acid methyl ester

Reagents, catalysts & solvents 1

HCID 7918Acetic AnhydrideSolvent2×

Procedure

To 8 mL of acetic anhydride at −20° C. is added 1.2 mL of nitric acid (d=1.5). The mixture is kept at −20° C., and a solution of 4-thiophen-2-yl-butyric acid methyl ester (1.84 g, 10.0 mmol) in 12 mL of acetic anhydride is added dropwise. The reaction mixture is stirred for 10 minutes after completion of addition, and poured into an ice-water mixture. The product is extracted with ethyl acetate and the organic layer is washed with 10 N aqueous sodium hydroxide solution, dried and concentrated. The residue is purified by flash column chromatography eluting with 1:4 ethyl acetate:hexane to provide 1.32 g of 4-(5-nitro-thiophen-2-yl)-butyric acid methyl ester as a yellow oil; 1H NMR (DMSO-d6) δ 1.93 (quintet, J=7 Hz, 2H), 2.41 (t, J=7 Hz, 2H), 2.88 (t, J=7 Hz, 2H), 3.59 (s, 3H), 7.04 (d, J=5 Hz, 1H), 8.01 (d, J=5 Hz, 1H); MS 229.0 (M)+.

Workup

  1. customis kept at −20° C.
  2. additionafter completion of addition
  3. extractionThe product is extracted with ethyl acetate
  4. washthe organic layer is washed with 10 N aqueous sodium hydroxide solution
  5. customdried
  6. concentrationconcentrated
  7. customThe residue is purified by flash column chromatography
  8. washeluting with 1:4 ethyl acetate

Sources & evidence

ORD record
ord-428f1f5596d141b0bd4ef094d4044da1
Source dataset
uspto-grants-2006_01
Patent number
US06987116B2

Linked notes

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