Abstract
Regioselective electro-bromination of benzofuran (2) was achieved successfully by an adequate choice of solvents and bromide salts to afford 5-bromobenzofuran (1), 5,7-dibromobenzofuran (3), and 2,3-dibromo-2,3-dihydrobenzofuran (4), respectively. Upon electrolysis of benzofuran (2) in AcOH/H2O (100/1) containing NH4Br, substitution at the C(5)-position of benzofuran (2) proceeded smoothly to afford 5-bromobenzofuran (1). After passage of totally 4 F/mol of electricity in a similar medium, 5,7-dibromobenzofuran (3) was obtained as a sole product. On the other hand, electrolysis of benzofuran (2) in CH2Cl2/H2O (1/1) and/or AcOH/H2O (10/1) in the presence of either NaBr or NH4Br afforded 2,3-dibromo-2,3-dihydrobenzofuran (4), exclusively.
| Original language | English |
|---|---|
| Pages (from-to) | 825-831 |
| Number of pages | 7 |
| Journal | Heterocycles |
| Volume | 54 |
| Issue number | 2 |
| Publication status | Published - Feb 1 2001 |
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Keywords
- 2,3-Dibromo-2,3-dihydrobenzofuran
- 5-Bromobenzofuran
- Benzofuran
- Bromination
- Electrolysis
ASJC Scopus subject areas
- Organic Chemistry
Cite this
Substitution vs. addition. Regioselective electro-bromination of benzofuran. / Tanaka, Hideo; Kawakami, Yusuke; Kuroboshi, Manabu; Torii, Sigeru.
In: Heterocycles, Vol. 54, No. 2, 01.02.2001, p. 825-831.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Substitution vs. addition. Regioselective electro-bromination of benzofuran
AU - Tanaka, Hideo
AU - Kawakami, Yusuke
AU - Kuroboshi, Manabu
AU - Torii, Sigeru
PY - 2001/2/1
Y1 - 2001/2/1
N2 - Regioselective electro-bromination of benzofuran (2) was achieved successfully by an adequate choice of solvents and bromide salts to afford 5-bromobenzofuran (1), 5,7-dibromobenzofuran (3), and 2,3-dibromo-2,3-dihydrobenzofuran (4), respectively. Upon electrolysis of benzofuran (2) in AcOH/H2O (100/1) containing NH4Br, substitution at the C(5)-position of benzofuran (2) proceeded smoothly to afford 5-bromobenzofuran (1). After passage of totally 4 F/mol of electricity in a similar medium, 5,7-dibromobenzofuran (3) was obtained as a sole product. On the other hand, electrolysis of benzofuran (2) in CH2Cl2/H2O (1/1) and/or AcOH/H2O (10/1) in the presence of either NaBr or NH4Br afforded 2,3-dibromo-2,3-dihydrobenzofuran (4), exclusively.
AB - Regioselective electro-bromination of benzofuran (2) was achieved successfully by an adequate choice of solvents and bromide salts to afford 5-bromobenzofuran (1), 5,7-dibromobenzofuran (3), and 2,3-dibromo-2,3-dihydrobenzofuran (4), respectively. Upon electrolysis of benzofuran (2) in AcOH/H2O (100/1) containing NH4Br, substitution at the C(5)-position of benzofuran (2) proceeded smoothly to afford 5-bromobenzofuran (1). After passage of totally 4 F/mol of electricity in a similar medium, 5,7-dibromobenzofuran (3) was obtained as a sole product. On the other hand, electrolysis of benzofuran (2) in CH2Cl2/H2O (1/1) and/or AcOH/H2O (10/1) in the presence of either NaBr or NH4Br afforded 2,3-dibromo-2,3-dihydrobenzofuran (4), exclusively.
KW - 2,3-Dibromo-2,3-dihydrobenzofuran
KW - 5-Bromobenzofuran
KW - Benzofuran
KW - Bromination
KW - Electrolysis
UR - http://www.scopus.com/inward/record.url?scp=0035249358&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0035249358&partnerID=8YFLogxK
M3 - Article
VL - 54
SP - 825
EP - 831
JO - Heterocycles
JF - Heterocycles
SN - 0385-5414
IS - 2
ER -