L-Proline → HCID 59899144, compound

Participants

Reaction Steps

A stirred solution of 2-amino-3-formylpyridine (1.40 mmol), 1-13 (420 mg, 1.08 mmol) and proline (162 mg, 1.40 mmol) in ethanol (10 mL) was heated at reflux for 14 h, and the cooled to ambient temperature. The reaction mixture was diluted with ethyl acetate and washed with saturated aqueous sodium hydrogen carbonate, saturated aqueous sodium chloride, and dried over anhydrous magnesium sulfate. The reaction mixture was filtered and concentrated at reduced pressure. The resulting oil was purified by flash column chromatography (silica gel, 3:0.3:0.3 to 8:0.8:0.8% ethanol/ammonium hydroxide/water in ethyl acetate) to give 1-14 as an inseparable mixture of diastereomers. To a stirred solution of this mixture in methanol (20 mL) was added a slurry of 10% palladium on carbon (80 mg) in ethanol (2 mL). The resulting suspension was stirred under a slight overpressure of hydrogen for 16 h. The reaction mixture was filtered through Celite and concentrated at reduced pressure. The resulting oil was purified by flash column chromatography (silica gel, 3:0.3:0.3 to 8:0.8:0.8% ethanol/ammonium hydroxide/water in ethyl acetate) to give 1-15 as an inseparable mixture of diastereomers.

Provenance & Evidence