To a solution of (3R)-3-methylmorpholine (51.6 mg, 0.510 mmol, Tyger Scientific, Ewing, USA) in methanol (2 mL) was added formaldehyde (37% aqueous) (0.038 mL, 0.510 mmol). The reaction mixture was stirred at room temperature for 1 hour before the addition of 4-isocyano-2-(trifluoromethyl)benzonitrile (100 mg, 0.510 mmol, commercially available from Priaxon AG, Munich, Germany) and trimethylsilylazide (0.068 mL, 0.510 mmol). The reaction mixture was stirred at room temperature overnight (approximately 18 hours) and the solvent removed under vacuum. The residue was purified by MDAP. Fractions containing the desired compound were combined and the solvent removed. The residue was partitioned between saturated NaHCO3 (2 mL) and DCM (5 ml). The organic layer was collected via a hydrophobic frit and the solvent removed under a stream of argon. The compound was dissolved in a minimum of diethyl ether before the addition of 1N HCl in diethyl ether (2 mL) leading to precipitation. The ether was removed under vacuum and the product further dried under vacuum at 40° C. overnight to yield the title compound as a white solid (57 mg).
