Stannous Chloride → 1-(2,5-Diaminopyrimidin-4-yl)indazole-6-carbonitrile

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Reaction Conditions

Reaction Steps

A mixture of 1-(2-amino-5-nitro-3,4-dihydropyrimidin-4-yl)-1H-indazole-6-carbonitrile (40% purity, 400 mg, 0.64 mmol) and tin (II) chloride (577 mg, 2.56 mmol) in ethanol (15 mL) was heated at 60° C. for 2 hr then at 70° C. for 3 hr. LC-MS (Method B) showed 11% desired product and 74% degradation. The reaction mixture was concentrated in vacuo. The residue was vigorously stirred with a mixture of saturated aqueous Rochelle salt (potassium sodium tartrate (20 mL), saturated aqueous NaHCO3 (20 mL) and EtOAc (30 mL) for 30 min. The EtOAc layer was washed with brine (10 mL), dried over Na2SO4, filtered and concentrated in vacuo. The crude was purified by column chromatography (Biotage) (100% EtOAc) to give the title compound as a pale yellow solid: 1H NMR (250 MHz, DMSO) δ 5.40 (2H, br. s.), 6.30 (2H, s), 7.69 (1H, dd, J=8.38, 1.22 Hz), 8.01-8.25 (2H, m), 8.62 (1H, d, J=0.76 Hz), 9.31 (1H, s); LC-MS: m/z=+252.0 (M+H)+.

Provenance & Evidence