A solution of tert-butyl 3-((4-fluoro-2-methylphenyl)amino)azetidine-1-carboxylate (D30) (240 mg, 0.856 mmol), acetic acid (0.49 ml, 8.56 mmol), Formaldehyde 36% wt. in water (0.066 ml, 0.856 mmol) and sodium(triacetoxy)borohydride (725 mg, 3.424 mmol) in 1,2-dichloroethane (7 ml) was stirred under N2 atmosphere at room temperature for 1 day. NaHCO3 sat. solution (25 ml) was added. After phase separation, the aqueous layer was extracted with dichloromethane (2×35 ml). The organics after solvent evaporation were purified by Biotage SNAP-Si cartridge (10 g) eluting with cyclohexane/ethylacetate from 90/10 up to 80/20. Collected fractions after solvent evaporation afforded the title compound (D33) (170 mg)
