Reaction of N-(4-pyridylmethyl)-amide N-oxides with acetic anhydride

Reaction of N-(4-pyridylmethyl)-amide N-oxides with acetic anhydride

Tetrahedron Letters Vol. 21, pp 3921 - 3924 @Pergmon Press Ltd. 1980, Printed in Great Britain REACTION OF N-(4-PYRIDYLMETHYL)-AMIDE Miguel Departa...

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Tetrahedron Letters Vol. 21, pp 3921 - 3924 @Pergmon Press Ltd. 1980, Printed in Great Britain

REACTION

OF N-(4-PYRIDYLMETHYL)-AMIDE Miguel

Departamento

F. Braha*

de Quimica

Universidad Summary:

dimerization

the pyridine

N-OXIDES

and Maria

Complutense.

acetic

prompted

us to study

anhydride

new type of dimer When $ was

not previously treated

This

(s, 12H, 4CH3),

2H, 2H para-phenyl), 280-2°C

under

aceticanhydride

at the atom attached

(DMF-water)

atoms

of g with

to

this

neuroleptic

for new derivatives

of heteroaromatic

reviewed

reagent,

N-oxi-

by Oae and 0gino3

which

resulted

in a

reported. anhydride

acetic

compound

was

under

reflux

recrystallized

to its spectroscopic

6.80

(s, 2H, 2CH),

8.60

(d,

for 1.5 hours

from DMF, m.p.

data.

which

showed

suggested

awhite

336-8°C

absorption

place.

8.90

liquors

bands

The

to

: 478 (M+), 240

'H-NMR

(F3C-COOH

suggested

(s,

spectrum

a solid

(22%), m.p.

3200 and 1650 cm-' showed

to 2 in which

signals

90MHz):

7.35

(d, 4H, 4H a-pyridine). produced

in IR near

mass

similar

The fact that

in the NMR spectrum

MS

(s, 4H, 4H ortho-phenyl),

of the mother

a structure

ture of the 2 and E isomers

7.20

4H, 4H B-pyridine),

pressure

has taken

had disappeared

of the reaction

has been excellently

NH and CO respectively.

peak at 476 which

J, is a powerful The search

: 3300 and 1630 (NH and CO amide);

reduced

due to the amide hydrogen

with

as N,N' -di-(3,5-dimethylbenzoyl)-1,2-di-(4-pyridyl)-

$, according

+ 1); IR (KBr)

Removal,

with

identified

ethylenediamine 2.30

Spain.

occurs

metabolite.

interest

which

the reaction

(42%) appeared.

give a compund (Mt)/2

the main

as the theoretical

des with

solid

Quimicas.

ring.

its N-oxide * $ being

of & as well

ANHYDRIDE

Rodriguez

N-oxides

N-(4-pyridylmethyl)-3,5_dimethylbenzamide' agent,

ACETIC

de Ciencias

Madrid-3.

This dimerization

compounds.

WITH

L. LBpez

Facultad

Orgbnica.

of N-(4-pyridylmethyl)-benzamide

Reaction

yielded

0040-4039/80/1001-j92jsO2.00/0

a molecular

the loss of two

due to the methine

that the compound

could

protons

be a mix-

of N,N'-di-(3,5-dimethylbenzoyl)-l,2-di-(4-pyridyl)-

vinylenediamine and 7.45

4. IH-NMR spectrum (CDC13 90 MHz) : 2.39 (s, 12H, 4CH3), 7.18 % (two doublets corresponding to the 4 hydrogen atoms of the s position

of the pyridine

ring

2H, 2H ortho-phenyl), corresponding

in the Z/E mixture), 7.63

7.28

(s, ZH, 2H para-phenyl),

(s, 2H, 2H ortho-phenyl),

to the 4 hydrogen

atoms

8.46 and 8.59

of the a position

7.55

of the pyridine

ring

the Z/E mixture). Catalytic relationship

hydrogenation

between

of $, yielded

the compounds.

2 which

confirmed

(s,

(two doublets

the structural

in

3924

a)i R-CONH--HP

-

OAc R-CONS-

R;H-$tj

~

-;GJNHCO-R

=

F-NHCO-R

+ R-CONH-f R= 3,5-(

CH3)2-C6H3-

The fact that takes

place

rization

of which

similar

explains

2 or $ suggesting

In order

to comfirm

same conditions with

to give R alkyl

that

process follows

of this dimeriration treated

the corresponding

reac-

to &. The

the yield

cage"mechanism

N-oxides.

the extension

with

rise

to modify

N-oxides

were

give

a "radical

for other

2, dime-

in a transfer

would

does not seem

the reaction

the reaction

rise to radicals

of 2. The latter,

or inhibitors

that

to suggest

giving

by Oae and Traynelis4

N-(4-pyridylmethyl)-amide diamines

seems

process

disproportionation

precusors

to that observed

isolated

cleavage

the formation

by a radical

of radical

of either

2 and ,4 were

via a homolytic

tion followed presence

I

acetic

reaction

other

anhydride

under

the

N,N'- diacyl-1,2-di-(4-pyridyl)-ethylen

or aryl groups.

References. 1. M.F. BraRa, J.M. Castellano and F.P. Rabaddn, Arch. de Farmacol. Y Toxicol., IV, 237 (1978). 2. P.D.G. Jal6n, E. Gonzrilez, A. Idoipe, 1704 (1979).

M.R.M. LarraRaga and M. F. Brafia,Arzneim-Forsch,29_,

3. S. Oae and K. Ogino, Heterocycles,5, 583 (1977). 4. a) S. Oae, T. Kiato and Y. Kitaoka,

., j34_, 3359 (1962).

b) S. Oae, Y. Kitaoka and T. Kitao, Tetrahedron, 2D_,2685 (1964). c) V.J. Traynelis and A.I.

Gallagher, J. Am. Chem. Sot., 87, 5710 (1965).

Acknowledgements:This work was supported by the grants given to one of the authors (M.L.L.R.) from‘LaboratoryMade S.A. of Madrid and the Ministry of Education and Science of Spain, which is gratefully acknowledged. (Received in UK 2 July 1980)