Reactivity Studies of [1]Benzothieno[3,2-b][1]benzofuran

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Title:Reactivity Studies of [1]Benzothieno[3,2-b][1]benzofuran
Creators:
Pihera, Pavel
Svoboda, Jiří
Journal or Publication Title:
Collection of Czechoslovak Chemical Communications, 65, 1, pp. 58-76
Uncontrolled Keywords:Fused heterocycles, Benzoylation, [1]Benzothieno[3,2-<i>b</i>][1]benzofuran, Metallation, Bromination, Oxidations, Nitration, Formylation, Electrophilic substitutions, Acetylation

Abstract

Electrophilic substitution and metallation reactions of the title compound <strong>1</strong> were studied. Bromination, acetylation, benzoylation, formylation, and nitration usually afforded nonseparable mixtures of 2- and 7-substituted derivatives as the main product. Disubstitution reactions preferably led to 2,7-disubstituted derivatives. [1]Benzothieno[3,2-<i>b</i>][1]benzofuran 10,10-dioxide (<strong>17</strong>) and [1]benzothieno[3,2-<i>b</i>][1]benzofuran 10-oxide (<strong>18</strong>) can be selectively obtained by oxidation of <strong>1</strong>. Mononitration of <strong>17</strong> and <strong>18</strong> led selectively to corresponding 7-nitro derivatives <strong>19</strong> and <strong>21</strong>, respectively. Only sulfoxides <strong>19</strong> and <strong>20</strong> were successfully reduced. Reduction of the 5-oxide moieties was successful only at the sulfoxide stage. Metallation of <strong>1</strong> with butyllithium preferably proceeds in positions 1 and 6; subsequent reaction with methyl iodide or carbon dioxide led to the corresponding dimethyl derivative <strong>25</strong> or esters <strong>26</strong> and <strong>27</strong>, respectively. An unusual addition of butyllithium to the central double bond of <strong>1</strong> was also observed in a small extent producing 9b-butyl-4b,9b-dihydro[1]benzothieno[3,2-<i>b</i>][1]benzofuran-4b-ol (<strong>29</strong>). The structures of all products were elucidated by NMR. <p>

Title:Reactivity Studies of [1]Benzothieno[3,2-b][1]benzofuran
Creators:
Pihera, Pavel
Svoboda, Jiří
Uncontrolled Keywords:Fused heterocycles, Benzoylation, [1]Benzothieno[3,2-<i>b</i>][1]benzofuran, Metallation, Bromination, Oxidations, Nitration, Formylation, Electrophilic substitutions, Acetylation
Divisions:Life and Chemical Sciences > Institute of Organic Chemistry and Biochemistry > Collection of Czechoslovak Chemical Communications
Journal or Publication Title:Collection of Czechoslovak Chemical Communications
Volume:65
Number:1
Page Range:pp. 58-76
ISSN:0010-0765
E-ISSN:1212-6950
Publisher:Institute of Organic Chemistry and Biochemistry
Related URLs:
URLURL Type
http://dx.doi.org/10.1135/cccc20000058UNSPECIFIED
ID Code:1623
Item Type:Article
Deposited On:06 Feb 2009 17:11
Last Modified:06 Feb 2009 16:11

Citation

Pihera, Pavel; Svoboda, Jiří (2000) Reactivity Studies of [1]Benzothieno[3,2-b][1]benzofuran. Collection of Czechoslovak Chemical Communications, 65 (1). pp. 58-76. ISSN 0010-0765

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