Facile synthesis of aminonaphthoquinone Mannich bases by noncatalytic multicomponent reaction López-LópezLluvia Itzel Nery-FloresSendar Daniel Sáenz-GalindoAidé LoeraDenisse de 2017 <p>Mannich bases are formed in a noncatalytic multicomponent reaction, which is promoted by ultrasound irradiation. The procedure avoids the use of toxic solvents, catalyst, and purification, generating the desired compounds in excellent yields and short reaction times.</p>