Stannous Chloride → 5-Methyl-3-phenyl-1H-indazole

Participants

Reaction Steps

To a solution of 2-amino-5-methylphenyl phenyl ketone (2.0 g, 9.5 mmol) in HCl (45 mL of a 6M solution) at 0° C. was added sodium nitrite (NaNO2) (719 mg, 10.4 mmol) in water (2 mL). The reaction was stirred for 30 min when the homogeneous solution was added dropwise to a solution of SnCl2 (5.88, 26 mmol) in concentrated HCl (15 mL) at room temperature. The reaction was stirred for 30 min when it was filtered. The solid was then taken up in ethyl acetate (80 mL) and saturated sodium bicarbonate (80 mL). The suspension was then filtered and the ethyl acetate layer dried (Na2SO4) and concentrated to give the product (1.59 g, 80% yield). (1H NMR (DMSO-d6) δ 7.96 (d, 2H), 7.85 (br s, 1H), 7.54–7.46 (m, 3H), 7.39 (t, 1H), 7.24 (d, 1H), 2.45 (s, 3H); ES-MS (m/z) 209 [M+1]+.

Provenance & Evidence