Synthesis and Antimicrobial Activity of Furochromone, Benzofuran and Furocoumarin Derivatives Bearing Sulfonyl Moiety

New visnagin-9-sulfonamide derivatives <b>3</b> and <b>4a−c</b> were synthesized through the reaction of visnagin-9-sulfonyl chloride <b>2</b> with amino compounds. Acetylation of compounds <b>4b</b> and <b>4c</b> gave the monoacetyl and diacetyl derivatives <b>5</b> and <b>6</b>, respectively. Diazotization reaction of compound <b>4b</b> afforded the corresponding benzotriazole derivative <b>8</b>. Pyrazole and thiopyrimidine derivatives <b>9</b> and <b>10</b> were obtained via the opening of pyrone ring upon reaction of compound <b>3</b> with hydrazine hydrate and thiourea, respectively. In addition, hydrolysis of compound <b>3</b> with potassium hydroxide furnished the visnaginone derivative <b>11</b> which used as starting material for synthesize benzofuran derivatives <b>12−14</b> and bergaptene derivatives <b>15−17</b>. The synthesized compounds were tested for antimicrobial activity. Furochromone derivatives <b>3</b>, <b>4a−c</b>, <b>5</b>, <b>6</b> and <b>8</b> (visnagin-9-sulfonamide derivatives) demonstrate moderate antibacterial and antifungal activities compared with the antibacterial and antifungal activites of the standard drugs. Benzofuran derivatives <b>11−14</b> (visnaginone derivatives) showed the lowest antimicrobial activity among all the compounds investigated in this study. Furocoumarin derivatives <b>15a,b</b>, <b>16</b> and <b>17</b> (furobenzopyransulfonamide [bergaptensulfonamides]) are moderately active against all the tested strains. <br><a rel="license" href="http://creativecommons.org/licenses/by/4.0/"><img alt="Creative Commons License" style="border-width:0" src="https://i.creativecommons.org/l/by/4.0/80x15.png" /></a> This work is licensed under a <a rel="license" href="http://creativecommons.org/licenses/by/4.0/">Creative Commons Attribution 4.0 International License