Reaction #47203

Reaction equation

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

Yield 34.0%

Solvents

methanol

Conditions

Workup

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

Procedure

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.

Source