Synthesis, Antimicrobial, and Anti-HIV1 Activity of Quinazoline-4(3H)-one Derivatives

The present investigation aims to synthesize 11 compounds of quinazoline-1 derivatives and to test their antimicrobial and anti-HIV1 activities. A quick-witted method was developed for the synthesis of novel substituted quinazolinone derivatives by summarizing diverse diamines with benzoxazine reactions, and it demonstrated the benefits of typical reactions, handy operation, and outstanding product yields. These compounds were confirmed by elemental analysis, I？R, 1H NMR, 13C NMR, and mass spectra. Then antimicrobial and anti-HIV1 activities of the compounds were tested in-vitro. It was found that compounds 7–11 possessed a wide range of anti microbial and anti-HIV1 activity. 1. Introduction In spite of the fact that the chemistry quinazolinones have mesmerized the attention of researchers for a long time [1–3], the number of competent approaches to the synthesis of their derivatives containing functional groups is inadequate [4, 5]. The quinazolinone skeleton appears in many alkaloids, most commonly in the form of 4-(3H)-quinazolinone [6]. The quinazolinone moiety is an important pharmacophore showing many types of pharmacological activities. The quinazolinones are considered to be a potent structure for drug developments [7–9]. This has recently inspired the development of a new ring synthesis method. Several successful attempts have been made and recorded in the literature demonstrating promising outcomes [10–12]. The present investigation is a continuation of our earlier [13] study on quinazolinone derivatives. 2. Result and Discussion 2.1. Chemistry In the present investigation, an attempt was made to synthesize quinazolinone derivatives through a multistep process. For this purpose, the required 3(2-aminophenyl)-2-methyl quinazolin-4(3H)-one (1) was prepared according to the literature procedure [14, 15], the condensation reaction between benzoxazine and o-phenylene diamine using acetic acid. Formation of the product was confirmed by the formation of intellectual band at 1607？cm？1 (C=N stretching) along with a peak reading at 1699？cm？1 (C=O) in IR spectra. Benzoxazine [16] was converted to 3(2-aminophenyl)-2-methyl quinazolin-4(3H)-one (1) by nucleophilic substitution reaction with o-phenylenediamine along with appearance of new peak near 3398.5？cm？1 (NH2 stretching) and 3317.09？cm？1 (N–H stretching) which also helped in assigning structure of (1). When (1) was treated with benzoyl chloride [17, 18] in presence of pyridine as a base, nucleophilic reaction took place at the o-phenylenediamine site of molecule, and, as a result, quinazolinone ring