Dimethylformamide → ethyl 5-formyl-1H-pyrrole-2-carboxylate

HRID 1372405

Reaktionsgleichung

Reaktionsgleichung von HRID 1372405
CN(C)[CH:3]=[O:4].P(Cl)(Cl)(Cl)=O.[NH:11]1[CH:15]=[CH:14][CH:13]=[C:12]1[C:16]([O:18][CH2:19][CH3:20])=[O:17].[OH-].[Na+]>ClC(Cl)C>[CH2:19]([O:18][C:16]([C:12]1[NH:11][C:15]([CH:3]=[O:4])=[CH:14][CH:13]=1)=[O:17])[CH3:20].[CH2:19]([O:18][C:16]([C:12]1[NH:11][CH:15]=[C:14]([CH:3]=[O:4])[CH:13]=1)=[O:17])[CH3:20]

Komponenten

7

Edukt 4

HCID 6228DimethylformamideHCID 14798Sodium HydroxideHCID 24813Phosphorus oxychlorideHCID 255670Ethyl 1H-pyrrole-2-carboxylate

Produkt 2

HCID 321485ethyl 5-formyl-1H-pyrrole-2-carboxylateAusbeute 50 %HCID 321486Ethyl 4-formyl-1H-pyrrole-2-carboxylateAusbeute 7 %

Reagenzien, Katalysatoren, Lösungsmittel 1

HCID 63651,1-DichloroethaneLösungsmittel3×

Versuchsvorschrift

To a solution of dimethylformamide (21 mL, 0.27 mol) in 75 mL of dichloroethane was added a solution of phosphorus oxychloride (25 mL, 0.27 mol) in 75 mL of dichloroethane at 0° C. The mixture was stirred at room temperature for 30 minutes and cooled to 0° C. To the mixture was added a solution of ethyl pyrrole-2-carboxylate (25 g, 0.18 mol) in 50 mL of dichloroethane dropwise. The resulting mixture was stirred at room temperature for 30 minutes and then at 40° C. for 1 hour. The mixture was poured into ice and basified to pH 11 with 5 N sodium hydroxide solution. The mixture was extracted with ethyl acetate and the extract washed with water, brine and dried over anhydrous sodium sulfate. The two products were separated by column chromatography (1:3 ethyl acetate:hexane) to give 15 g (50% yield) of 5-formyl-1H-pyrrole-2-carboxylic acid ethyl ester and 2 g (7% yield) of 4-formyl-1H-pyrrole-2-carboxylic acid ethyl ester. 1H-NMR (5-formyl-1H-pyrrole-2-carboxylic acid ethyl ester) (300 MHz, dimethylsulfoxide) δ 13.02 (br s, 1H, NH), 9.69 (s, 1H, CHO), 6.95 (d, 1H), 6.86 (d, 1H), 4.27 (q, 2H, CH3), 1.28 (t, 3H, CH3). MS m/z 167 [M+].

Aufarbeitung

  1. temperaturecooled to 0° C
  2. stirringThe resulting mixture was stirred at room temperature for 30 minutes
  3. waitat 40° C. for 1 hour
  4. extractionThe mixture was extracted with ethyl acetate
  5. washthe extract washed with water, brine
  6. dry with materialdried over anhydrous sodium sulfate
  7. customThe two products were separated by column chromatography (1:3 ethyl acetate:hexane)

Quellen und Nachweise

ORD-Eintrag
ord-7a1a2483cb444c199fd7cb74cd02388f
Quelldatensatz
uspto-grants-2007_01
Patentnummer
US07157577B2

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