Synthesis of Naphthopyranopyrimidines Using Formic Acid as an Effective Catalyst under Solvent-free Conditions

An environmentally friendly, one-pot, three-component synthesis of ۸,۱۰-dimethyl-۱۲-aryl-۱۲H-naphtho[۱′,۲′:۵,۶]pyrano[۲,۳-d]pyrimidine-۹,۱۱-diones was achieved via coupling aromatic of aldehydes, β-naphthol and ۶-amino-۱,۳-dimethyl uracil in the presence of formic acid as a catalyst under solvent-free conditions at ۹۰ °C. This method has several advantages, such as efficiency, good yield, short reaction time, cleaner reaction profiles, ease of product isolation, operational simplicity and inexpensive, effective and catalyst.