📕 Developments in the field of stereochemistry began in the nineteenth century. The concept of chirality was first introduced by Jean Baptiste Biot. The present book deals with the major issue that is N-N chiral axis in 3-monoaminoquinazolin-4-(3H)-one, 3-diacylaminoquinazolinones and mono- and di-aniline (DAA and MAA) derivatives. The book presents the how to synthesize and characterize different MAA, DAA, MAQ, and DAQ compounds. Last chapter focus on the chemoselectivity especially competitive reactions of pyrrolidine and piperidine, diethylamine and diphenylamine, ethanolamine and diethanolamine, succinimide and phthalimide with DAQs and competitive reaction of pyrrolidine and piperidine with diacylaniline derivatives and acetyl chloride. The density functional and time dependent density functional theories have been applied and discussed the N-N bond as chiral axis, electronic, spectroscopic data.