反应详情

2,3-Dihydro-benzo[1,4]dioxine-6-carbaldehyde (198 mg, 1.21 mmol, 1.0 eq) is added at room temperature to a stirred solution of trans-4-amino-cyclohexanecarboxylic acid methyl ester (200 mg, 1.21 mmol, 1.0 eq) in 1,2-dichloroethane (8 mL) and methanol (2 mL), followed by acetic acid (80 μL, 1.39 mmol, 1.15 eq) and sodium cyanoborohydride (99 mg, 1.57 mmol, 1.3 eq). After 15 hours stirring at room temperature, the reaction mixture is extracted with dichloromethane (3×20 mL) and a saturated sodium hydrogen carbonate aqueous solution (20 mL). The combined organic layers are dried over sodium sulfate, filtered and concentrated to afford trans-4-[(2,3-dihydro-benzo[1,4]dioxin-6-ylmethyl)-amino]-cyclohexanecarboxylic acid methyl ester as an orange oil (359 mg, 92% yield).

1. extractionthe reaction mixture is extracted with dichloromethane (3×20 mL)
2. dry with materialThe combined organic layers are dried over sodium sulfate
3. filtrationfiltered
4. concentrationconcentrated