With tetrakis(triphenylphosphine) palladium(0); 1,8-diazabicyclo[5.4.0]undec-7-ene In ethanol; water at 150℃; for 0.166667h; Microwave irradiation; Sealed vessel;
5.1.7. General procedure A for the preparation of the biphenyl-4-carbohydrazides 6l-6q
General procedure: 4-Iodobenzohydrazide (6g; 262 mg, 1.00 mmol) was reacted with the appropriate boronic acid 9 (1.00 mmol), 1,8-diazabicyclo[5.4.0]undec-7-ene (149 μL, 1.00 mmol) and 5 mol% tetrakis(triphenylphosphine)palladium(0) (58 mg, 0.050 mmol) in water (1 mL) and ethanol (1 mL). The reaction was conducted in a microwave device using a sealed microwave reaction vessel. The reaction mixture was stirred for 10 min at 150 °C, 60 W, ramp time 5 min, maximum pressure 250 psi. After cooling to room temperature the mixture was poured into a separating funnel. Water was added and the aqueous phase was extracted with ethyl acetate (3 × 20 mL). The collected organic layers were dried over anhydrous Na2SO4 and evaporated. Except for 6p, which was purified and isolated by silica gel chromatography (eluent: ethyl acetate), the crude products were used in the next step without further purification according to general procedure B yielding compounds 7l-q.