Original scientific paper

Study of Cyclization Mechanism of N-Substituted-2-amino- benzophenones into 1,4-Benzodiazepines; B-Participation of an Vinylogous Amide Nitrogen

M. Mihalić ; Institute of Organic Chemistry and Biochemistry, University of Zagreb, Zagreb, Croatia, Yugoslavia
V. Šunjić ; Institute of Organic Chemistry and Biochemistry, University of Zagreb, Zagreb, Croatia, Yugoslavia
P. Mildner ; Institute of Organic Chemistry and Biochemistry, University of Zagreb, Zagreb, Croatia, Yugoslavia
F. Kajfež ; Institute of Organic Chemistry and Biochemistry, University of Zagreb, Zagreb, Croatia, Yugoslavia

Abstract

2-(N-B-Bromoalkyl)-amino-5-substiJtuted ben:oophenones 28, 32,
33 .and 38 have been i:nduced by treatment in ethanolic solution of
hexamethyleintetramine or rammonia ·to ring c1osure into 1,4-beinzcidiazepiines
39-46. Deuterium B-labe1ed compound 28 gave on
cyclization two 1,4-benzodfazepiines (39 and 40) in the rntio 45/55,
reveal1ng B-par!ticipation of :nitrogen atom. The neighbouri:ng grnup
participa·tion was further investigated by deternniniing the ratio
and configuration of the 2- and 3-substituted chiral 1,4-benzodi.
azepines 1resulting on ring closure: 32 gave (S)-41 and (S)-42
(ratio 82/18), 33 gave (S)-43 and {S)-44 ~rntio 92/8), 38 gave 45 and
46 (ratio 58/42). High regioselectiviity was also 1observed for recyclization of aziridines 36 in (S)-41 and (R)-42 (rntio 63/37), and
37 in (S)-43 and (R)-44 (ratio 76/24), respectively. Arn opposite
stereochemical course of formaition of 42 and 44 f.rom 32 and 33,
as :Dram 36 and 37 is observed. Absolute configurntfon of (-)- and
( + )-42 and 44 was determined by comparison of their CD spectra
with those of (S)-50, and mecha1nistic scheme is offered accountLng
for all exper-imental results.

Keywords

Hrčak ID:

196475

URI

https://hrcak.srce.hr/196475

Publication date:

30.4.1976.

Visits: 840 *