Studies on complex compounds-IV copper complexes of quinazolone hydrazides

IHORG.

MUCL.

CHEM.

LETTERS

Vol.

3,

pp.

603-607,

1967.

Pergamon Press

Ltd.

Printed

In

Great

Brlteln~

STUDIES ON COMPLEX COMPOUNDS-IV COPPER COMPLEXES OF QUINAZOLONE C. H. Misra, Department

Surendra

of Pharmacology

S. Parmar and R. C. Arora

and Therapeutics,

Lucknow University,

Lucknow

(Recelv~ 9 June |96~ In revised ~

Co-ordination tubercular properties Sorkin et al(2), reported

of the complexes

study four complexes

3, India

Contrary tO the findings of

and Kuhn and Zillekan(W) of thiosemicarbazones

of copper(II)

have

by

from secondary amines.

2-methyl-3-(4'-benzhydrazide)-4-quinazolones as antitubercular

College

14 S ~ t ~ b e r ;967)

of isoniazid(1).

chelation with sulphur and nitrogen present

K. G. Medical

with copper has been shown to enhance anti-

Ginzras et al(3),

synthesis

HYDRAZIDES 1

In the

halide with some have been synthesized

compounds. EXPERIMENTAL

Preparation 2-Methyl-3-(~'-benzhydrazide)-~-quinazolones sized as reported earlier(5). shaking ethanolic quinazolone

The complexes were pmepared by

solution of CuCI2.2H20

hydrazide

and an appropriate

in a I:i molar ratio(6).

separated out were collected by filtration and finally with ether. chemical

analysis

were synthe-

The color,

The complexes which

and washed with ethanol

solubility,

melting point and

data of these copper complexes

are shown in

Table I. iSupported by a research grant from the State Council of Scientific and Industrial Research, Lucknow. Correspondence regarding this publication should be addressed to Professor S. S. Parmar. 603

604

STUDIES OH COMPLEX COMPOUNDS-IV

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Vol, 3, Me. 12

STUDIES ON COMPLEX COMPOUNDS-IV

605

Infra-red spectr a The infra-red spectra of the complexes were obtained with KBr films using Perkin-Elmer Infracord Spectrophotometer.

The

energies and intense bands between 700-3500 cm -I for each of the complexes are given in Table II. 2-Methyl-3-(4'-benzhydrazide)-4quinazolone was used for comparison. TABLE II FREQUENCIES(cm -I) ASSIGNMENT FOR COPPER COMPLEXES

Compound

I

II

III

IV

NH 2 Stretching

NH 2 Deformation

3124 3028

1638

1614

3124 3028

1625

1601

3126 3028

1635

1611

1638

1611

1668

1627

3192 3028

V

CO Stretching

3283 3185

Compound numbers are as reported in Table I. Compound V denotes 2-methyl-3-(4'-benzhydrazide)-4-quinazolone(parent ligand). RESULTS AND DISCUSSION The elemental analysis of these complexes have indicated that the quinazolone hydrazides and cupric chloride react in the ratio of i:i. The infra-red spectra of the complexes show only two bands at 3124 cm -I and 3028 cm -I in the NH 2 stretching region. The -CONHNH 2 grouping in the parent ligand~ 2-methyl-3-(4'-benzhydra-

606

STUDIES ON COMPLEX COMPOUNDS-IV

zide)-4-quinazolone,

Vol. 3, No. 12

accounts for two bands at 3283 cm -I and

3185 cm -I. The resulting shift to the lower frequencies

indicates

possible involvement of NH group for co-ordination. At present it is difficult to establish the specific nitrogen participating in the complex formation.

Inability of 2-methyl-3-phenyl-4-quinazolone

(devoid of hydrazide moiety) and cupric chloride to form complex compound,

in our separate experiment,

favours participation of the

hydrazide moiety. Assuming that -CONHNH 2 group takes part in the complex formation,

the lowering of CO stretching has indicated the

involvement of CO group of the hydrazide moiety in such complex formation.

The CO group at position 4 of the quinazolone nucleus

is less active and is located at a distance from the nitrogen atoms of the hydrazide group.

Lowering of the NH deformation band provides

additional support for the involvement of NH 2 group for the binding of the oxygen to the metal ion. Since no extra peak was observed in the infra-red spectra of the quinazolone hydrazide(Compound V~ Table II) it is difficult to assess the availability of H atom of the secondary NH group for co-ordination. indicated the possible structure~

These results have

as shown in Table I~ for the

copper complexes of 2-methyl-3-(4'-benzhydrazide)-4-quinazolones. Similar structure has been suggested by Sorkin et al(2) for the copper complex of isoniazid. Acknowledgments The authors wish to express their appreciation to Professor K. P. Bhargava and Dr. J. P. Barthwal for their advice and encouragement and to Drs. M. L. Dhar and Nitya Anand of Central Drug Research Institute,

Lucknow for pmoviding facilities for micro-

analysis and infra-red measurements.

Vol. 3, No. 12

STUDIES ON COMPLEX COMPOUNDS-IV

607

REFERENCES i.

V. C. BARRY,

Chemotherapy

Butterworths, 2.

of Tuberculosis.

p. 131.

London(1964).

E. SORKIN~ W. ROTH, and H. ERLENMEYER,

Helv.

Chim. Acta.

35, 1736(1952). 3.

B. A. GINZRAS,

R. W. HORNAL~and

C. H. BAYLEY,

Can. J. Chem.

3.__88, 712(1960). 4.

R. KUHN and F. ZILLEKAN,

U.S. Patent No. 2,695,911(1954).

5.

S. S. PARMAR and R. C. AROEA,

6.

C. H. MISRA,

S. S. PARMAR~

Chem. 28, 147(1966).

Can. J. Chem. 4__~, 2100(1966).

and S. N. SHUKLA~

J. Inorg.

Nucl.