4-Chloropyrimidine hydrochloride → 4-(4-fluoro-3-(4-(pyrimidin-4-yloxy)piperidine-1-carbonyl)benzyl)phthalazin-1(2H)-one

Participants

Reaction Conditions

Reaction Steps

Sodium tert-butoxide (125 mg, 1.30 mmol) was added in one portion to 4-(4-fluoro-3-(4-hydroxypiperidine-1-carbonyl)benzyl)phthalazin-1(2H)-one (2a) (150 mg, 0.39 mmol) in tetrahydrofuran (2 ml) at 20° C. The resulting suspension was stirred at 20° C. for 10 minutes. 4-chloropyrimidine hydrochloride (49.5 mg, 0.43 mmol) was added in one portion and the resulting mixture was stirred at 50° C. for 2 hours. Sodium tert-butoxide (41 mg, 0.43 mmol) was added in one portion followed by 4-chloropyrimidine hydrochloride (65 mg, 0.43 mmol) and the mixture heated at 50° C. for 2 hours and then stirred at ambient temperature overnight. The crude product was purified by ion exchange chromatography using an SCX column. The desired product was eluted from the column using 2M NH3/MeOH and pure fractions were evaporated to dryness to afford crude product. This was purified by preparative HPLC (Sunfire column, 5μ silica, 19 mm diameter, 100 mm length), using decreasingly polar mixtures of water (containing 0.1% TFA) and MeCN as eluents. Fractions containing the desired compound were evaporated to dryness to afford the desired compound as a solid (91 mg, 50.4%); 1H NMR (400.132 MHz, DMSO) δ 1.53-1.61 (1H, m), 1.66-1.73 (1H, m), 1.88-1.94 (1H, m), 2.02-2.09 (1H, m), 3.14-3.25 (1H, m), 3.32-3.48 (2H, m), 3.98-4.07 (1H, m), 4.34 (2H, s), 5.33-5.39 (1H, m), 6.95 (1H, d), 7.21-7.25 (1H, m), 7.37-7.44 (2H, m), 7.80-7.84 (1H, m), 7.87-7.90 (1H, m), 7.97 (1H, d), 8.26 (1H, d), 8.54 (1H, d), 8.79 (1H, s), 12.56 (1H, s); m/z (LC-MS, ESI+), RT=1.69 (M+H 460.6).

Provenance & Evidence