Hydrochloric Acid → Ethyl furo[3,2-b]pyridine-6-carboxylate

HRID 1383010Notes

Reaction equation

HRID 1383010 reaction equation
Cl.C(ONC([C:10]1[CH:14]=[CH:13][O:12][CH:11]=1)=O)(C)(C)C.[CH2:15]([O:17][C:18]([CH:20]([CH:23]=O)[CH:21]=O)=[O:19])[CH3:16].[OH-].[NH4+:26]>C(O)C.[Cl-].[Zn+2].[Cl-]>[O:12]1[C:11]2[C:10](=[N:26][CH:21]=[C:20]([C:18]([O:17][CH2:15][CH3:16])=[O:19])[CH:23]=2)[CH:14]=[CH:13]1

Participants

7

Reactant 4

HCID 313Hydrochloric AcidHCID 14923Ammonium HydroxideHCID 11029955Ethyl 2-formyl-3-oxopropanoateHCID 21273332HCID 21273332, compound

Product 1

HCID 14372157Ethyl furo[3,2-b]pyridine-6-carboxylate

Reagents, catalysts & solvents 2

HCID 3007855ZincchlorideCatalystHCID 702EthanolSolvent2×

Conditions

Temperature
80 °C

Procedure

To a solution of conc. hydrogen chloride (100 mL) containing zinc chloride (11.6 g, 83 mmoL) was added 3-(t-butoxycarbamoyl)furan (13.8 g, 75.4 mmol). After stirring for 5 minutes, the reaction mixture was diluted with ethanol (60 mL) and a solution of ethoxycarbonylmalonaldehyde (11.6 g, 80.6 mmol) in ethanol (40 mL) was added. This mixture was warmed at 80° C. for two hours and then cooled and poured into ice/water and made basic with ammonium hydroxide. The product was extracted into methylene chloride, dried over anhydrous sodium sulfate, filtered through a pad of charcoal and evaporated. This residue was chromatographed on silica gel eluting with chloroform to give 5.92 g of purified product. Crystallization from hexane provided product with, mp: 63°-65° C.

Workup

  1. temperaturecooled
  2. extractionThe product was extracted into methylene chloride
  3. dry with materialdried over anhydrous sodium sulfate
  4. filtrationfiltered through a pad of charcoal
  5. customevaporated
  6. customThis residue was chromatographed on silica gel eluting with chloroform

Sources & evidence

ORD record
ord-fc2105a9c14b43028cd794010fb9ab2d
Source dataset
uspto-grants-1989_02
Patent number
US04808595

Reaction notes

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