Incredible Role of Glycerol in Multicomponent Synthesis of 2,3-Dihydroquinazoline-4(1H)-ones and 1-Amidoalkyl-2-naphthols

An efficient and green synthesis of 1-amidoalkyl-2-naphthols via one-pot three-component condensation of aromatic aldehydes, acetamide and 2-naphthol in the presence of catalytic amounts of glycerosulfonic acid in glycerol as a green solvent was elaborated. Also a simple method for the one-pot three-component synthesis of 2,3-dihydroquinazoline-4(1H)-ones using of isatoic anhydride, aldehydes and ammonium acetate in the presence of glycerol as a green catalyst and solvent was described. In this light we introduced the brilliant and valuable role of glycerol in the synthesis of 2,3-dihydroquinazoline-4(1H)-ones and 1-amidoalkyl-2-naphthols

Fluorescent Biaryl Uracils with C5-Dihydro- and Quinazolinone Heterocyclic Appendages in PNA

There has been much effort to exploit fluorescence techniques in the detection of nucleic acids. Canonical nucleic acids are essentially nonfluorescent; however, the modification of the nucleobase has proved to be a fruitful way to engender fluorescence. Much of the chemistry used to prepare modified nucleobases relies on expensive transition metal catalysts. In this work, we describe the synthesis of biaryl quinazolinone-uracil nucleobase analogs prepared by the condensation of anthranilamide derivatives and 5-formyluracil using inexpensive copper salts. A selection of modified nucleobases were prepared, and the effect of methoxy- or nitro- group substitution on the photophysical properties was examined. Both the dihydroquinazolinone and quinazolinone modified uracils have much larger molar absorptivity (~4–8×) than natural uracil and produce modest blue fluorescence. The quinazolinone-modified uracils display higher quantum yields than the corresponding dihydroquinazolinones and also show temperature and viscosity dependent emission consistent with molecular rotor behavior. Peptide nucleic acid (PNA) monomers possessing quinazolinone modified uracils were prepared and incorporated into oligomers. In the sequence context examined, the nitro-substituted, methoxy-substituted and unmodified quinazolinone inserts resulted in a stabilization (∆Tm = +4.0/insert; +2.0/insert; +1.0/insert, respectively) relative to control PNA sequence upon hybridization to complementary DNA. All three derivatives responded to hybridization by the “turn-on” of fluorescence intensity by ca. 3-to-4 fold and may find use as probes for complementary DNA sequences