SYNTHETIC STUDIES ON INDOLES AND RELATED-COMPOUNDS .43. NEW FINDINGS ON THE HEMETSBERGER-KNITTEL REACTION

Authors
MURAKAMI Y WATANABE T SUZUKI H KOTAKE N TAKAHASHI T TOYONARI K OHNO M TAKASE K SUZUKI T KONDO K
Citation
Y. Murakami et al., SYNTHETIC STUDIES ON INDOLES AND RELATED-COMPOUNDS .43. NEW FINDINGS ON THE HEMETSBERGER-KNITTEL REACTION, Chemical and Pharmaceutical Bulletin, 45(11), 1997, pp. 1739-1744
Citations number
23
Categorie Soggetti
Pharmacology & Pharmacy",Chemistry
Journal title
Chemical and Pharmaceutical Bulletin → ACNP
ISSN journal
00092363
Volume
45
Issue
11
Year of publication
1997
Pages
1739 - 1744
Database
ISI
SICI code
0009-2363(1997)45:11<1739:SSOIAR>2.0.ZU;2-P
Abstract
In the Hemetsberger-Knittel reaction for indole synthesis, the interme diate ethyl 2-azido-3-hydroxy-3-arylpropionate (4) was found to be for med in the reaction of arylaldehyde 1 with ethyl azidoacetate at a low er temperature (-30 degrees C) as the main product, while only ethyl 2 -azidocinnamate (2) is known to be formed at a higher temperature (0 d egrees C). It was also found that fluoride ion was effective for obtai ning 4. Compound 4 was converted to 2 in good yield by treatment with SOCl2/pyridine or SOCl2/Et3N. A trial application of this reaction to ketone is also described.