Synthesis of 2-amino-4H-chromene derivatives under microwave irradiation and their antimicrobial activity

Libraries of 2-amino-4H-chromenes, were efficiently synthesized via one-pot, three-component reactions of 5-chloro-3-methyl-1-aryl-4,5-dihydro-1H-pyrazole-4-carbaldehyde (1a-c), 2-naphthols (2a-f) and malononitrile in the presence of catalytic amount of ammonium acetate under microwave irradiation. The protocol offers rapid synthesis of structurally diverse 2-amino-4H-chromenes for biological screening. All the synthesized compounds were evaluated for their antimicrobial activity, and several compounds exhibited moderate to potent antimicrobial activity.