Synthesis of novel 3-[(2<i>R</i>*)-2-[(2<i>S</i>*)-6-fluoro-3,4-dihydro-2<i>H</i>-chromen-2-yl]-2-hydroxyethyl]-urea/thiourea derivatives and evaluation of their antimicrobial activities Madhava Rao Mannam Srimurugan S. Pramod Kumar Naga Raju Chamarthi Prasad K. R. S. 10.6084/m9.figshare.8798450.v1 https://tandf.figshare.com/articles/journal_contribution/Synthesis_of_novel_3-_2_i_R_i_-2-_2_i_S_i_-6-fluoro-3_4-dihydro-2_i_H_i_-chromen-2-yl_-2-hydroxyethyl_-urea_thiourea_derivatives_and_evaluation_of_their_antimicrobial_activities/8798450 <p>A new series of biologically active 3-[(2<i>R</i>*)-2-[(2<i>S</i>*)-6-fluoro-3,4-dihydro-2<i>H</i>-chromen-2-yl]-2-hydroxyethyl]-urea/thiourea derivatives (<b>1</b>) have been designed and synthesized in four steps from 6-fluoro-3,4-dihydro-2-(oxiran-2-yl)-2<i>H</i>-chromene (<b>2</b>). The structures of newly synthesized compounds (<b>1a–j</b>) were confirmed by <sup>1</sup>H, <sup>13</sup>C NMR, and HRMS. The major advantages of the present article include the development of an efficient eluent system for good separation of diastereomers (<b>2a</b> and <b>2b</b>) with high yields and synthesis of (<i>R</i>*)-2-(benzylamino)-1-((<i>S</i>*)-6-fluoro-3,4-dihydro-2<i>H</i>-chromen-2-yl)ethanol (<b>3</b>) in high yields (87%) from epoxide <b>(2a)</b> through new reaction conditions. The synthesized compounds (<b>1a–j</b>) exhibited moderate to excellent antimicrobial activities against both bacterial strains (gram + Ve and gram –Ve strains) and fungal strains. Among the tested compounds, promising lead compounds were identified (compounds <b>1a</b> and <b>1d</b> against bacterial strains and compound <b>1h</b> and <b>1j</b> against fungal strains) and their antimicrobial activities are comparable with the reference standard.</p> 2019-07-08 12:59:50 Chromane nebivolol intermediate urea and thiourea derivatives antimicrobial activity