Ethylenediamine → N-methyl-N-(3-styryl-1H-indazol-6-yl)-benzene-1,3-diamine

Participants

Reaction Conditions

Reaction Steps

To N-methyl-N-{3-styryl-1-[2-(trimethyl-silanyl)-ethoxymethyl]-1H-indazol-6-yl}-benzene-1,3-diamine (237 mg, 0.5 mmol) was added 1M TBAF in THF (10.1 mL, 10.1 mmol), followed by ethylenediamine (0.34 mL, 5.04 mmol, 10 equiv). The resulting mixture was heated to 70° C. for 5 h. The reaction was then quenched with saturated NaHCO3 (10 mL) and extracted 3×35 mL EtOAc. The pooled EtOAc phase was washed 5×20 mL H2O, then brine (20 mL), dried with Na2SO4, decanted and concentrated under reduced pressure to a foam. The crude material was purified by silica gel chromatography (9:1 dichloromethane/ethyl acetate) to give N-methyl-N-(3-styryl-1H-indazol-6-yl)-benzene-1,3-diamine as a foam (120 mg, 70% yield). Rfsm 0.73, Rfp 0.27 (dichloromethane:ethylacetate 7:3); 13C NMR (75 MHz, CDCl3) δ 150.3, 148.8, 147.5, 147.5, 143.9, 143.4, 137.5, 131.1, 130.3, 129.3, 128.9, 128.2, 127.9, 126.7, 121.0, 120.5, 117.0, 116.0, 112.6, 109.8, 109.0, 98.3, 40.7; LCMS (ESI) [M+H]/z Calc'd 341, Found 341. Anal. Calc'd: C, 77.62; H, 5.92; N, 16.46. Found: C, 76.16; H, 5.88; N, 15.95.

Provenance & Evidence