反应详情

Tert-butyl carbazate (350 mg, 2.65 mmol), HBTU (1.01 g, 2.66 mmol), and N,N-diisopropylethylamine (923 μL, 5.30 mmol) were added to a methylene chloride (5 mL) solution of commercially available 4,5-dimethylfurancarboxylic acid (248 mg, 1.77 mmol), and the mixture was stirred overnight at room temperature. After the reaction solution was concentrated, to the residue, a saturated aqueous solution of sodium bicarbonate was added, and the mixture was subjected to extraction with methylene chloride and dried over anhydrous sodium sulfate, and then, the solvent was distilled off. The obtained residue was dissolved in methylene chloride (6 mL). To the solution, trifluoroacetic acid (1.5 mL) was added, and the mixture was stirred at room temperature for 1.5 hours. The reaction solution was concentrated to obtain 4,5-dimethylfuran-2-carbohydrazide.

1. concentrationAfter the reaction solution was concentrated, to the residue
2. additiona saturated aqueous solution of sodium bicarbonate was added
3. extractionthe mixture was subjected to extraction with methylene chloride
4. dry with materialdried over anhydrous sodium sulfate
5. distillationthe solvent was distilled off
6. dissolutionThe obtained residue was dissolved in methylene chloride (6 mL)
7. additionTo the solution, trifluoroacetic acid (1.5 mL) was added
8. stirringthe mixture was stirred at room temperature for 1.5 hours
9. concentrationThe reaction solution was concentrated