Diisopropylethylamine → HCID 90311805, compound

Participants

Reaction Conditions

Reaction Steps

(2S,5S)-tert-butyl 2,5-dimethyl-4-(3-nitropyridin-4-yl) piperazine-1-carboxylate. To a solution of (2S,5S)-tert-butyl 2,5-dimethylpiperazine-1-carboxylate hydrochloride (1.17 g, 4.67 mmol, Acesys Pharmatech, A1653, Sample ID 119-99-18) in 2-Propanol (20 mL) was added 4-chloro-3-nitropyridine (1.11 g, 7.00 mmol, Alfa Aesar, Ward Hill, Mass.) and DIPEA (4.06 mL, 23.33 mmol). The mixture was heated and stirred at 85° C. for 2 h. Additional DIPEA (0.81 mL, 4.67 mmol) was added and the heat was raised to 90° C. The mixture was stirred at this temperature for 18 h. The mixture was then cooled to RT and concentrated. The residue was diluted with EtOAc (150 mL) and washed with water (15 mL) followed by brine (15 mL) and then dried over MgSO4. The crude material was purified by silica gel chromatography (30-70% EtOAc in hexanes) to afford (2S,5S)-tert-butyl 2,5-dimethyl-4-(3-nitropyridin-4-yl)piperazine-1-carboxylate (918 mg, 2.73 mmol, 59% yield) as a yellow solid. MS (ESI, pos. ion) m/z: 337.1 (M+1). 1H NMR (400 MHz, CDCl3) δ ppm 8.82 (s, 1 H), 8.38 (d, J=5.9 Hz, 1 H), 6.99 (d, J=6.1 Hz, 1 H), 4.12 (dd, J=14.0, 4.4 Hz, 1 H), 3.99-4.07 (m, 1 H), 3.94 (dt, J=10.8, 5.5 Hz, 1 H), 3.23 (dd, J=13.5, 9.4 Hz, 1 H), 2.98 (dd, J=14.1, 10.8 Hz, 1 H), 2.77 (dd, J=13.5, 5.7 Hz, 1 H), 1.46 (s, 9 H), 1.16 (d, J=6.3 Hz, 3 H), 1.13 (d, J=6.1 Hz, 3 H).

Provenance & Evidence