Reaktion #47203

Reaktionsgleichung

sodium methoxide

1-cyano-3,3-dimethylbut-1-en-2-yl 4-methylbenzenesulfonate

diethyl aminomalonate hydrochloride salt

→

methyl 3-amino-5-tert-butyl-1H-pyrrole-2-carboxylate

Ausbeute 34.0%

Lösungsmittel

methanol

Reaktionsbedingungen

Aufarbeitung

1. 1
   workup.ADDITIONAfter the addition
2. 2
   Sonstigethe solvent was removed under vacuum
3. 3
   workup.DISSOLUTIONthe crude product was dissolved in water
4. 4
   Extraktionextracted with ethyl acetate
5. 5
   WaschenThe combined organic layers was washed with brine
6. 6
   Sonstigedried
7. 7
   Sonstigethe solvent removed under vacuum
8. 8
   SonstigeThe crude product was purified by column chromatography (silicagel, dichloromethane:methanol 95:5)

Vorschrift

To a stirred sodium methoxide solution (15% by weight, 80 mL total) was added drop-wise a solution of 1-cyano-3,3-dimethylbut-1-en-2-yl 4-methylbenzenesulfonate (10.0 g, 36 mmol) and diethyl aminomalonate hydrochloride salt (9.0 g, 43 mmol) in methanol (50 mL). After the addition was completed, the reaction was stirred at room temperature for 2 hours, the solvent was removed under vacuum and the crude product was dissolved in water and extracted with ethyl acetate. The combined organic layers was washed with brine, dried and the solvent removed under vacuum. The crude product was purified by column chromatography (silicagel, dichloromethane:methanol 95:5) to afford 2.4 g of the desired methyl 3-amino-5-tert-butyl-1H-pyrrole-2-carboxylate used as such in the next step.

Quelle