Studies of heteroaromaticity-LXVII. Syntheses of N-vinyliminopyridinium ylides and their intermolecular reactions with acetylenic compounds

Pergamon Pree a.

TetrahedronLettera No. 51, PP 5245 - 5240s 1972.

STUDIES OF HETEROAROMATICITY-LXVII.l

Printed in Great Britain.

SYNTHESES OF N-VINYL-

IMINOPYRIDINIUM YLIDES AND THEIR INTERMOLECULAR REACTIONS WITH ACETYLENIC COMPOUNDS Tadashi Institute

of

Sasaki,

Applied

Nagoya University,

Ken Kanematsu

Organic

and Akikazu

Chemistry,

Chikusa,

Nagoya,

Faculty

Kakehi of

Engineering,

464 Japan

(Receivedin Japm 2 November1972; receivedin UK for publication21 Iiovember 1972) N-Vinyliminopyridinium and vinylhalide character the

in the

and the

preparation On the

scarcely

presence

resulting

of

readily

hand,

investigated

cyclization

Recently,

of

reaction

we have

highly

reported

but

adduct.

its

die-isomer

2

Related

to

N-vinyliminopyridinium their

to

acetylenic

dinium

with

1,5-dipolar

a useful

ylides

has been

in the

cyclization

derivative to give

effect,

the

for

in N-(ta%m-2', hinders

the

cycli-

dihydro-bicyclo-

we attempted

3’, 3’-disubstituents

method

dihydro-compounds.

3 ‘-substituent

facility

substituent

ylides

report compound

to prepare

the

and some reactions

of

here of

the preparation

and the

intermolecular

reaction

N-(3’-methyl-3’-methoxycarbonylethenyl)iminopyri-

ylides. Treatment

crylate

this

such

reactivity

ylide with

are

N-imines

ylides. We wish

with

cyclizes

pyridinium

and their of

that

3’-dimethoxycarbonylethenyl)iminopyridinium zation

2,3,4

heteroaromatics

their

from

show a remarkable

reactions

intermolecular

because

obtainable

alkali,

of

nitrogen-bridged

other

reactions.

ylides,

L in

of

the

pyridinium

presence

temperature

gave

the

accompanied

with

two kinds

derivatives

&

and 1.48(each

N-imine

of

excess

corresponding of

CH3),

potassium ylide

bicyclic

and -5a as unstable 3H, s,

hydriodide

3.56

pale

z

with

carbonate

3a(21%),

m-p.

compounds(57%), yellow oils,

and 3.68Ceach

5245

3H, s,

methyl

b-bromometha-

in chloroform at room 0 1540cm-l, 85-87 9 v,"-";; dihydropyrazolopyridine

6(CC14), 0CH3),

i%teP 4.33

dlca,

1.31

and 4.84(each

No. 51

5246

lH,

3a-H)

br s,

ppm, and

6 (CC14) t 2.26(3H,

s,

7.0,

8.OH2,

7.28(1H,

(lH,

dd,

7.0,

products,

not

obtained,

but

J=8.0,

in the

same reaction the

these

case

1,3-dipolar

ylides,

room temperature and $b,

2-6 1 I

to

in good

R,&

R2

a

H

H

b

H

Me

Me

H

C

1. -*

the

analogous

these

bromide

the

yields,

from and 5

corresponding

respectively.

of

-2b and -2c and 1,

and 3c(77%, &

uith

1,4c --

140-143’

and -5c were

among N-vinyliminopyridinium supported

compounds

did

bicyclic

not

primary were

under

were

N-imines

produced with

cycloadducts. aromatized

are

1,

by us. the a followed

By contrast, readily

3-metylpyrazolopyridine These

proposed

reported

cyclize

compounds

pyridinium

and 3,

those

as previously

even

ylides

2,

in Scheme 1.

e

1.

-3b and -3c with

dimethyl

at

derivatives,

summarized

K2

the

m.p.

-C02Me

Scheme

J=

and 8.26

-HBr

1

I

of

t,

treatments

of

-C02Me

Reactions

br

2-H),

reaction

the

6.86(111, s,

and 6b(59%),

of

6-H),

116-119’,

7.55(1H,

be expected,

reactions5

and &,

give

4-H),

nmr spectra

suggested

2

Br_Me

of

as might

of hydrogen

dihydro-compounds

5

m.p.(picrate)

7.OH2,

and pyrazolopyridine

cycloaddition

by elimination

J~7.0,

1.5H2,

s,

similar

with

conditions

g,

From similar

145-148’),

in comparison

br t,

ppm.

Grossly

That of

@

dd,

dihydropyrazolopyridine

structures

the

6.50(1H,

7-H)

m.p.

produced.

ylide,

CH3),

1.5Hz,

3b(25%,

were

),

5-H),

3-methylpyrazolopyridine

acetylenedicarboxylate

2

5a7

No. 51 in benzene

at room temperature

-7a(30%)

ylides, 124-126’). 8(28%, were

(lH,

powders,

Furthermore,

in

obtained:

2;

G(CDC13),

3.78(3H,

s,

0CH3),

J=a.OHz,

4.27(28,

d,

Table

1.

Compd. -3a

C-2 a.23 m

-3b

7.95

-3c

2.65

-7a

8.39 m

-7b

8.12

-7c

2.64

8

2.66

2.33

S

6.94

S

7.43 d

7.71 q

7.40 d

7.37

pyridinium

that

with

of

8.12

8.40

7.43

7.76

7.42

2.66

the

acetylenic

on the basis

strongly

to have

d

of

the ylides

methoxycarbonyl

1,3-dipolar

other

group6

hand,

These

4.12

S

molecule

results

reported

rearranged of are

6.OHz

J=8.0,

t

of

addition

on dimethyl

rearrangement

reaction

1.26

as a result

ylide

the

J=8.0,

9

Michael-type

has been

S

S

3.70

1.96 d

3.72

3.71(6H) S

S

S

S

3.58

2.03

3.76

3.69 S

after

similar

6.OHz

S

3.64

may be considered

cycloaddition

compound. 899

S

S

S

3.73

3.67

1.95

7.66

Js9.0,

S

S

S

same reagent

On the

3.60

S

7.69

N-vinyliminopyridinium

with

1.88

S

S

S

1.98

S

d

Q

3.65

S

S

Interestingly,

and Zugravescu. to

2.40

2.64

/

the

S

S

S

a.35

7.43 d

methylide

of

3.67

1.89

7.61

8.39 m

7.79 q

dicarboxylate.

J=12.0Hz,

elucidation

showed

S

S

S

7.45 d

ilO;in -

br d,

OCH, (OCH,CH,)

1.94

S

2.65

S

of

123-125’)

was accomplished

C-3’

8.10

S

rearrangement

m.p.

1.

S

S

The formation

7.47(1H,

Structural

8.19

7.75

7.65m

S

carbanion

2.33 S

2.40

propiolate,ylide

9(51%,

nmr spectra

m

S

S

4-H))

C-2’

8.23

S

-

their

C-6

c-5

7.37m

S

m.p.

N-Ylides

c-4

C-3

-3c and ethyl

-7c and&

as shown in Table

NMR Data of

and -7c(80%,

0CH2CH3), 1.62(3H, d, J=l.SHz, OCH2CH3), 6.05(1H, br, NH), 7.06

J=7.0Hz,

E,

105-lOa’),

J=7.0Hz,

=CHNH). -

analyses;

structure

m.p. of

J=a.OHz,

2,

N-dienyliminopyridinium

derivative

t,

d,

ylides

and spectral

common ylide

reaction

q,

J=13.0Hz,

N-dienyliminopyridinium physical

-7b(53%,

1.30(3H,

7.37(1H,

5-H),

NHCH=), and 7.73(1H, -

of

the

corresponding

and 3-vinylpyridine

147-1500),

d,

the

as amorphous

m.p.

CH3),

gave

in the

cationotropic of

the

acetylene-

reaction

recently

of

by Leonte

compound

2 was similar

N-acyliminopyridinium summarized

6.0 Hz

in Scheme 2.

ylide

5248

No. 51

,

C02Et J

F02Et

Mmv: M%eQ R

M

ADC;

Et)

-uAfJ

‘C02Et(or Me)

9 EP; *C02Et,

CO Me(or

-2

2e

M

Cf$tO:M:

Z

11

MeOOCGCOOMe

Scheme

2.

References 1. Part LXVI of this series, T. Sasaki, K. Kanematsu and M. Murata, Jetrahedron, in press. 2. T. Sasaki, K. Kanematsu and A. Kakehi, J. Org. Chem., 37, 3106(1972) 3. Y. Tamura, N. Tsujimoto, Y. Sumida and M. Ikeda, Tetrahedron, g,

21(1972)

4. Y. Tamura, N. Tsujimoto and M. Ikeda, Chem. Commun., 310(1971) 5. Y, Tamura, A. Yamagami and M. Ikeda, Yakugaku Zasshi, 9l, 1154(1971) 6. R. M. Acheson, Accounts Chem. Res., i,

177(1971)

7. C. Leonte and I. Zugravescu, Tetrahedron Lett., 2029(1972) 8. T. Sasaki, K. Kanematsu and A. Kakehi, J. Org. Chem., 36, 2978(1971) 9. T. Sasaki, K. Kanematsu, A. Kakehi and G. Ito, Bull. Chem. Sot. Japan, 45, 2050(1972)