Reactions of 2-benzoselenopyrylium salts with hydrazine: a new easy access to 5H-2,3-benzodiazepines.
While the solvent-free reactions of the 2-benzoselenopyrylium salts (9) with methyl- or phenylhydrazine afforded the 1-hydrazino-1H-isoselenochromenes (11, 12), the treatment of the salts (9) with anhydrous hydrazine in dry acetonitrile resulted in a ring transformation to give the 5H-2,3-benzodiazepines (13) in one-pot under mild conditions in moderate yields.
Sashida
Haruki
H
Faculty of Pharmaceutical Sciences, Hokuriku University, Kanazawa, Japan. h-sashida@hokuriku-u.ac-jp
Ohyanagi
Kazuo
K
D001569:Benzodiazepines / Q000737:chemistry* / Q000378:metabolism*; D006834:Hydrazines / Q000737:chemistry / Q000378:metabolism*; D018036:Selenium Compounds / Q000737:chemistry / Q000378:metabolism*
C488443:2-benzoselenopyrylium; D006834:Hydrazines; D018036:Selenium Compounds; D001569:Benzodiazepines; C029424:hydrazine