2-Amino-5-chloropyridine → (2S)-3-[3-(tert-butyl-dimethylsilyl)oxyazetidin-1-yl]-N-(5-chloropyridin-2-yl)-2-hydroxypropanamide

Participants

Reaction Conditions

Reaction Steps

Trimethylaluminium (5.75 mL, 11.50 mmol) was added to 5-chloropyridin-2-amine (1.285 g, 10.00 mmol) in toluene (50 mL) cooled to 0° C. under nitrogen. The resulting solution was stirred at 0° C. for 10 minutes, (S)-methyl 3-(3-(tert-butyldimethylsilyloxy)azetidin-1-yl)-2-hydroxypropanoate (Intermediate AD3) (2.894 g, 10.00 mmol) in toluene (20 mL) was added, the reaction allowed to warm to room temperature and then heated at 80° C. for 4 hours. The reaction mixture was cooled, concentrated in vacuo and the residue neutralised with 1M citric acid (30 mL), diluted with water (25 mL) and extracted with EtOAc (2×30 mL). The combined organic extracts were dried (MgSO4) and evaporated to afford crude product which was purified by flash silica chromatography with EtOAc as eluent to afford the product (2.5 g, 65%). 1H NMR (400 MHz, DMSO) δ 0.01 (6H, s), 0.84 (9H, m), 2.65-2.70 (2H, m), 2.76-2.83 (2H, m), 3.56-3.59 (2H, m), 4.07-4.10 (1, m), 4.28-4.34 (1H, m), 5.78 (1H, s), 7.92 (1H, dd), 8.12 (1H, dd), 8.36-8.37 (1H, m), 9.87 (1H, s); m/z (ESI+) (M+H)+=386; HPLC tR=1.64 min.

Provenance & Evidence