Propylphosphonic anhydride → HCID 68753292, compound

Participants

Reaction Conditions

Reaction Steps

6-Nitro-1-((2-(trimethylsilyl)ethoxy)methyl)-1H-indazole-3-carbaldehyde (0.2 g, 0.622 mmol, prepared using N from 6-nitro-1H-indazole-3-carbaldehyde [Chempacific]), hydroxylamine hydrochloride (0.048 g, 0.68 mmol), and TEA (0.095 mL, 0.68 mmol) were combined in DMF (1.24 mL) in a sealed vial. 2,4,6-Tripropyl-[1,3,5,2,4,6]trioxatriphosphinane 2,4,6-trioxide (50% solution in DMF, 0.400 mL, 0.684 mmol) was added and the mixture was heated at about 100° C. for about 6 h. The mixture was allowed to cool to rt. EtOAc (15 mL) and an aqueous solution of saturated NaHCO3 (5 mL) were added and the layers separated. The aqueous layer was extracted with EtOAc (1×5 mL). The combined extracts were washed with 5% aqueous LiCl (3×10 mL). The combined extracts were washed with brine (10 mL), dried over MgSO4, filtered and evaporated under vacuum. The sample was re-dissolved in DCM and dry loaded onto silica gel (2 mL). The residue was purified by column chromatography (25 g silica gel) eluting with 10 to 25% EtOAc/heptane to provide 6-nitro-1-((2-(trimethylsilyl)ethoxy)methyl)-1H-indazole-3-carbonitrile (0.132 g, 67%): 1H NMR (400 MHz, DMSO-d6) δ 9.02 (dd, J=1.5, 1.1 Hz, 1H), 8.22-8.21 (m, 2H), 6.05 (s, 2H), 3.60-3.54 (m, 2H), 0.83-0.78 (m, 2H), −0.12 (s, 9H)

Provenance & Evidence