p-Toluenesulfonic acid → Methyl 2-methyl-7-nitro-2,3-dihydrobenzofuran-4-carboxylate

HRID 2364731Notes

Reaction equation

HRID 2364731 reaction equation
[CH2:1]([C:4]1[C:13]([OH:14])=[C:12]([N+:15]([O-:17])=[O:16])[CH:11]=[CH:10][C:5]=1[C:6]([O:8][CH3:9])=[O:7])[CH:2]=[CH2:3].C1(C)C=CC(S(O)(=O)=O)=CC=1.C(=O)(O)[O-].[Na+]>ClCCCl>[CH3:3][CH:2]1[CH2:1][C:4]2=[C:5]([C:6]([O:8][CH3:9])=[O:7])[CH:10]=[CH:11][C:12]([N+:15]([O-:17])=[O:16])=[C:13]2[O:14]1

Participants

5

Reactant 3

HCID 6101p-Toluenesulfonic acidHCID 516892Sodium BicarbonateHCID 59768300Methyl 2-allyl-3-hydroxy-4-nitro-benzoate

Product 1

HCID 68107419Methyl 2-methyl-7-nitro-2,3-dihydrobenzofuran-4-carboxylateYield 12.8%

Reagents, catalysts & solvents 1

HCID 111,2-DichloroethaneSolvent

Procedure

Methyl 2-allyl-3-hydroxy-4-nitro-benzoate 1d (800 mg, 3.30 mmol) was dissolved in 10 mL of 1,2-dichloroethane followed by the addition of 1 mL of p-toluenesulfonic acid. The reaction solution was stirred for 48 hours. The resulting solution was added with 10 mL of saturated sodium bicarbonate solution and extracted with dichloromethane (20 mL×3). The combined organic phase was washed with water (20 mL) and saturated sodium chloride solution (20 mL) successively, then dried over anhydrous magnesium sulfate, filtered and the filtrate was concentrated under reduced pressure. The resulting residue was purified by silica gel column chromatography to obtain the title compound methyl 2-methyl-7-nitro-2,3-dihydrobenzofuran-4-carboxylate 30a (100 mg, yield: 12.5%) as a yellow solid.

Workup

  1. extractionextracted with dichloromethane (20 mL×3)
  2. washThe combined organic phase was washed with water (20 mL) and saturated sodium chloride solution (20 mL) successively
  3. dry with materialdried over anhydrous magnesium sulfate
  4. filtrationfiltered
  5. concentrationthe filtrate was concentrated under reduced pressure
  6. customThe resulting residue was purified by silica gel column chromatography

Sources & evidence

ORD record
ord-51351d0447ac4bdabd5a60488bdc8bee
Source dataset
uspto-grants-2014_04
Patent number
US08691822B2

Reaction notes

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