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Kinetics of Cyclization of 2-(N-B-Bromoethyl)-amino-5-substituted Benzophenones into 1,4-Benzodiazepines

J. Kuftinec ; Institute for the Control of Drugs, 41000 Zagreb, Croatia, Yugoslavia
L. Klasinc ; »Ruder Boskovic« Institute, 41001 Zagreb, Croatia, Yugoslavia
F. Kajfež ; Department of Biomedical and Biochemical Research, CRC, Chemical Research - Company, 33048 San Giovanni al Natisone (UD), Italy
M. Mihalić ; Department of Biomedical and Biochemical Research, CRC, Chemical Research - Company, 33048 San Giovanni al Natisone (UD), Italy
E. Decorte ; Department of Biomedical and Biochemical Research, CRC, Chemical Research - Company, 33048 San Giovanni al Natisone (UD), Italy
V. Šunjić ; Department of Biomedical and Biochemical Research, CRC, Chemical Research - Company, 33048 San Giovanni al Natisone (UD), Italy


Puni tekst: engleski pdf 4.834 Kb

str. 213-223

preuzimanja: 180

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Sažetak

The overall pseudo-first order cyclization rates of 2-N-/J-bro
moethylamino-5-substituted benzophenones 1-3 into 1,4-benzodiazepines
7-9, determined in 60/o ethanolic ammonia at 100 °c, 115 °c,
and 125 °c respectively, were found to range between 1.0 X 10-• and
8.33 X 10-• s-1 for 1, between 1.6 X 10-4 and 5.83 X 10-• s·1 for 2 and
between 6.66 X 10-5 and 3.16 X 10-• s-1 for 3. Rate values calculated
from the rising concentrations of cyclization products 7-9 were
lower indicating the formation of stable intermediates. It is assumed
that these are protonated aziridine derivatives 4-6, since compounds
4 and 5 were identified as intermediates by TLC and GLC.
The formation rate for the model compound 2-amino-5-chlorobenzophenone
imine was found to be only 5.8 x 10-7 s-1 at 125 °C, which
eliminates imine (C=NH) derivatives of 1-3 as possible intermediates.
The ammonolysis rates of 3-phenylpropylbromide between
110 °c and 125 °c, were found to range from 1.5 X 10-4 to 4.16 X 10-•
s·1• These values revealed that the ~-participation of the N(2)-atom,
being a relatively rapid equilibrium, does not enhance the overall
cyclization rate. The following parameters characterize the overall
cyclization process; l'i H=I= = 50.0 ± 4.0 kJ mo1-1 and l'i S=I= = -156
± 5 J mo1-1 K-1 for 1, /'i H=I= = 89.9 ±.4.0 kJ moP K 1 for 2, l'i H=I= =
= 75.3 ± 4.0 kJ moi-1 and l'i S=I= = -89 ± 4 J moi-1 K' for 3.

Ključne riječi

Hrčak ID:

195946

URI

https://hrcak.srce.hr/195946

Datum izdavanja:

22.12.1978.

Posjeta: 427 *