Hydrochloric Acid → ethyl 3-amino-5-(furan-2-yl)-1H-pyrrole-2-carboxylate

HRID 1926017Notes

Reaction equation

HRID 1926017 reaction equation
CC1C=CC(S(O[C:12]([C:16]2[O:17][CH:18]=[CH:19][CH:20]=2)=[CH:13][C:14]#[N:15])(=O)=O)=CC=1.Cl.[NH2:22][CH:23](C(OCC)=O)[C:24]([O:26][CH2:27][CH3:28])=[O:25].[O-]CC.[Na+].Cl>C(O)C.O1CCCC1>[NH2:15][C:14]1[CH:13]=[C:12]([C:16]2[O:17][CH:18]=[CH:19][CH:20]=2)[NH:22][C:23]=1[C:24]([O:26][CH2:27][CH3:28])=[O:25]

Participants

7

Reactant 4

HCID 313Hydrochloric AcidHCID 2723922Sodium ethoxideHCID 3084143Propanedioic acid, 2-amino-, 1,3-diethyl ester, hydrochloride (1:1)HCID 545345202-Cyano-1-(2-furyl)vinyl 4-methylbenzenesulfonate

Product 1

HCID 10751393ethyl 3-amino-5-(furan-2-yl)-1H-pyrrole-2-carboxylateYield 33.3%

Reagents, catalysts & solvents 2

HCID 702EthanolSolvent2×HCID 8028TetrahydrofuranSolvent

Procedure

To a solution of 2-cyano-1-(2-furyl)vinyl 4-methylbenzenesulfonate (10.48 g) and diethyl aminomalonate hydrochloride (7.67 g) in a mixed solvent of ethanol (120 mL)-tetrahydrofuran (64 mL) was added dropwise a solution (36.9 mL) of 20% sodium ethoxide in ethanol under ice-cooling. After stirring at room temperature for 12 hrs, the reaction mixture was poured into ice water (350 mL) and adjusted to pH 7 with 1N hydrochloric acid. The organic solvent was evaporated under reduced pressure, and the residue was extracted with ethyl acetate (150 mL×3). The organic layers were combined, washed with saturated brine (100 mL), and dried over anhydrous magnesium sulfate. After concentration under reduced pressure, the residue was purified by silica gel column chromatography (eluent, hexane:methyl acetate=3:1→1:1) and the obtained solid was recrystallized from ethyl acetate-hexane to give the title compound (2.66 g).

Workup

  1. temperaturecooling
  2. customThe organic solvent was evaporated under reduced pressure
  3. extractionthe residue was extracted with ethyl acetate (150 mL×3)
  4. washwashed with saturated brine (100 mL)
  5. dry with materialdried over anhydrous magnesium sulfate
  6. concentrationAfter concentration under reduced pressure
  7. customthe residue was purified by silica gel column chromatography (eluent, hexane:methyl acetate=3:1→1:1)
  8. customthe obtained solid was recrystallized from ethyl acetate-hexane

Sources & evidence

ORD record
ord-c991b851240c498ebf42d948d73e79a2
Source dataset
uspto-grants-2012_05
Patent number
US08178543B2

Reaction notes

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