Ultrasound promoted synthesis of N-(substituted phenyl)-2-(7‑hydroxy-4-methyl-2H-chromen-2-ylidene)hydrazine-1-carboxamides as cytotoxic and antioxidant agents
New N-(substituted phenyl)-2-(7-hydroxy-4-methyl-2H-chromen-2-ylidene)hydrazine-1-carboxamides (5a-l) was synthesized in two steps using environmentally friendly ultrasound irradiation. The first step involved solvent free synthesis of 7-hydroxy-4-methyl-2H-chromen-2-one (3) by using catalytic amount (10% mol) of FeCl3. The second step involved condensation of intermediate 3 and hydrazine carboxamide