Potassium Carbonate → HCID 68283988, compound

HRID 1487211Notes

Reaction equation

HRID 1487211 reaction equation
[OH:1][C:2]1[C:9]([N+:10]([O-:12])=[O:11])=[CH:8][CH:7]=[CH:6][C:3]=1[CH:4]=O.Br[CH:14](C(OC)=O)[C:15]([O:17][CH3:18])=[O:16].C(=O)([O-])[O-].[K+].[K+]>[Br-].C([N+](CCCC)(CCCC)CCCC)CCC.C1(C)C=CC=CC=1>[N+:10]([C:9]1[C:2]2[O:1][C:14]([C:15]([O:17][CH3:18])=[O:16])=[CH:4][C:3]=2[CH:6]=[CH:7][CH:8]=1)([O-:12])=[O:11]

Participants

6

Reactant 3

HCID 11430Potassium CarbonateHCID 70087Dimethyl bromomalonateHCID 789342-Hydroxy-3-nitrobenzaldehyde

Product 1

HCID 68283988HCID 68283988, compoundYield 81%

Reagents, catalysts & solvents 2

HCID 74236Tetrabutylammonium BromideCatalystHCID 1140TolueneSolvent

Procedure

A mixture of 2-hydroxy-3-nitrobenzaldehyde (4.3 g, 25.7 mmol), dimethyl 2-bromomalonate (5.95 g, 28.3 mmol), potassium carbonate (5.32 g, 38.6 mmol) and tetra-n-butylammonium bromide (0.8 g, 2.5 mmol) in toluene (100 mL) was heated at reflux with a Dean-Start trap for 5 hours. After cooling to room temperature, the mixture was evaporated and purified by silica gel chromatography (dichloromethane) to afford the product methyl 7-nitrobenzofuran-2-carboxylate (4.6 g, yield 81%). 1H NMR (400 MHz, CDCl3) δ ppm 8.31-8.33 (dd, 1H, J=1.2 Hz, 8.0 Hz), 8.02-8.04 (dd, 1H, J=1.2 Hz, 8.0 Hz), 7.66 (s, 1H), 7.46-7.50 (t, 1H, J=8.0 Hz), 4.03 (s, 3H).

Workup

  1. temperaturewas heated
  2. temperatureat reflux with a Dean-Start trap for 5 hours
  3. customthe mixture was evaporated
  4. custompurified by silica gel chromatography (dichloromethane)

Sources & evidence

ORD record
ord-6b90608555c5408fb9053e2dd9e8f0ed
Source dataset
uspto-grants-2016_08
Patent number
US09428508B2

Reaction notes

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