Ammonia → HCID 57474451, compound

Participants

Reaction Steps

To an argon purged vial fitted with a magnetic stirbar and containing 54 (324 mg, 1.15 mmol) was cannulated a solution of Pd2(dba)3 (53 mg, 0.058 mmol), and Tri-t-butyl phosphine solution (0.34 mL, 10%, 0.11 mmol) in dry THF (8 mL). The flask was fitted with a condenser and a 1M solution of lithium hexamethyldisilane in THF (3.45 mL, 3.45 mmol) was added. The reaction was placed in a metal heating block and heated to reflux. The reaction was stirred at this temperature for 16 hours. TLC (10% 2M ammonia in methanol, 90% dichloromethane) revealed all starting material had reacted. The reaction was cooled to room temperature and quenched with 1M aqueous hydrogen chloride (15 mL). The acidic reaction was extracted with ethyl acetate (3×10 mL). The aqueous phase was basified with 3N sodium hydroxide (8 mL) and partitioned into ethyl acetate (3×10 mL). The organics were washed with brine, dried over magnesium sulfate, and treated with charcoal. Filtration through celite, concentration and further drying under high vacuum afforded a dark yellow oil. Purification of the product was performed using silica gel column chromatography (5-10% 2M ammonia in methanol, 95-90% dichloromethane) Yield: 162 mg of brown oil, compound 55 (65%). 1H NMR (CDCl3) δ 7.76 (br s, NH), 7.17-7.14 (d, 1H, J=8.4 Hz), 6.92-6.90 (dd, 2H, J=2.1, 4.5 Hz), 6.67-6.64 (dd, 1H, J=2.1, 8.4 Hz), 2.73-2.68 (t, J=7.5, 2H), 2.41-2.36 (t, J=7.5 Hz, 2H), 2.26 (s, 8H).

Provenance & Evidence