Methyl 3-formyl-4,5-dimethyl-1H-pyrrole-2-carboxylate → Methyl 3-formyl-4,5-dimethyl-1-[(1S,2S)-2-methylcyclopropylmethyl]pyrrole-2-carboxylate

Participants

Reaction Steps

Potassium tert-butoxide (3.49 g, 35.1 mmol) was added to a solution of methyl 3-formyl-4,5-dimethylpyrrole-2-carboxylate (5.79 g, 31.9 mmol) and 18-crown-6 (0.41 g, 1.55 mmol) in tetrahydrofuran (130 ml) and the mixture was stirred at room temperature for 1 hour. After dropwise addition over 30 minutes of (1S,2S)-2-methylcyclopropylmethyl bromide (5.71 g, 38.3 mmol) to the reaction mixture at 50° C., the mixture was heated under reflux for 3 hours. Potassium tert-butoxide (0.36 g, 3.22 mmol) and (1S,2S)-2-methylcyclopropylmethyl bromide (0.48 g, 3.21 mmol) were further added to the mixture and this mixture was heated for 1 hour. The reaction mixture was poured into ice-water and extracted with ethyl acetate. The extract was washed with water and a saturated aqueous sodium chloride solution and then dried over anhydrous magnesium sulfate. The solvent was removed in vacuo to afford the desired compound (8.26 g, 100%) as a pale brown oil.

Provenance & Evidence