Reactions of group IV organometallic compounds X A novel synthesis of substituted chloroformamides or guanidine by the reaction of organosilylamines and isocyanidedichloride

Reactions of group IV organometallic compounds X A novel synthesis of substituted chloroformamides or guanidine by the reaction of organosilylamines and isocyanidedichloride

Tetrahedron Letters No.18, ppO 1421-1423, 1969. Pergamon Press. Printed in Great Britain. REACTIONS OF GROUP IV ORGANOMETALLIC COMPOUNDS Xl A NOV...

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Tetrahedron Letters No.18, ppO 1421-1423,

1969. Pergamon Press.

Printed in Great Britain.

REACTIONS OF GROUP IV ORGANOMETALLIC COMPOUNDS

Xl

A NOVEL SYNTHESIS OF SUBSTITUTED CHLOROFORMAMIDINES OR GU~,NIDINr: BY THE REACTION OF ORGANOSILYLAMINES AND ISOCYANIDF~ICHLORII>E

KENJI ITOH,

1)epartment

OP

AKIRA NOLAdA,

AND

YOSHIO ISHII

Synthetic Chemistry, Faculty of Engineering,

Nagoya University.

(Received in Japan 12 February

Furo-cho, Chikusa-ku, Nagoya,

Japan

1969;received in lK for publication 10 March 1969)

Several addition reactions of organosilylsmines to unsaturated compounds* or cyclic compounds3'5 were extensively studied during these few years. In this publication, reactions between trimethylsilylamines and phenylisocyanidedichloride(&) are reported, which occur at 85O

for 24 hours and

afford chloroformamidines(H) in excellent yield through expulsion of trimethylchlorosilane.

Cl //N-Ph

85'

/ Ph-N=C

+

Me3Si-NR2 F

Cl-cy

+

Me3SiCl

(1)

\

Cl n:

1

TABLE I

included reaction conditions, yield of products, and physical

properties of chlorofonnamidines, which were identified by elementary analysis, infra-red, and nmr

spectra.

This reaction would offer a convinient method

for the preparation of substituted chloroformamidines.

1421

No.18

1422

TABLE

I

Chloroformamidines(P) by the Reaction of & with Trimethylsilyldialkylamines

Yield ($1

Reaction conditions

B.p. of &

$ C=N

R Me3SiCl

('C- hrs.)

a

cH3

rr

44

54

7WO.05

1660

88/0.07

1660

%+5

85-24

89

83

C

n-c3H7

75-16

93

84

&

(cm-l) _____

85-24

b

When

("c/mmHg)

1660

105/0.3

was treated with further one mole of trimethylsilylamine,

N-phenyl-N',N',N",N''-tetramethylguanidine (E) was obtained in 98.55;in the together with

case of R=CH3

could be prepared from the reaction between similarly.

Guanidine III

69";of trimethylchlorosilane.

2:l mole ratio of

We3SiNMe2 and &

N-Phenyl-N',N',N",N''-tetrsmethylguanidine (III) was identified

as picrate ( m.p. 157', Calcd. for

C17HzON607 ; C, 48.57, H, 4.80.

Found;

C, 48.36, H, 4.32). NKe2

ga

+

850 Me3Si-NMe2 ----------+ 24 hrs.

/ Ph-N=C \

+

Me SiCl 3

(2)

IWe

III

However, similar reaction did not proceed in the case of trimethylsilyldiethyl-

or

di-n-propylamine, probably because of steric hindrance of

dialkylamino group. In the reaction of N-methylhexamethyldisilazane with I , the anticipated chloroformamidine(2)

could never be isolated and the products obtained were

methylphenylcarbodiimide (7&)

and trimethylchlorosilane (43>")which suggested

subsequent P-elimination of IV

as eq. 3.

No. I8

Me

+

I

Cl I+ Ph-N=C -

!

-Me3SiCl

/ Me3Si-N \ SiMe3

$5'-72hrs.



Ph-N=C=N-Me

Iv-

+

SiMe3 N-Me

(3)

Me3SiCl

Similar j-elimination of trimethylchlorosilane was also observed in the reaction of &

with lithium bis(trimethylsilyl)amide.

equimolar amounts of LiN(SiMe312

at 100'

Treatment of &

with

for 24 hrs. afforded trimethylchloro-

silane, lithium chloride, and trimethylsilylphenylcarbodiimide(65% based on converted 1. :

b. poel 49O; ?~~3_si

&C=N

2170 Cm-' ,

&+

LiN(SiMe3)2

9.72(9B), ?c6i5 2.95-3.05(5R) in ccl4;

as well as recovered I (6046).

-Ide3SiC1 ) Ph-NCN-SiMe3

-LiCl Ph-N=CI

1

Extensive study to utilize the above reactions as synthetic methoa of various chloroformamidines, guanidines, and carbodiimides, is now in progress.

REFERENCES 1. Part IX.

K. Itoh, M. Fukui, Y. Ishii, Tetrahedron Letters, 3867 (1968).

2. bl. F. Lappert, P. B. Prokai, Adv. Orpanometal. Chem., ~01.

5, 225(1967).

3. K. Itoh, S. Sakai, Y. Ishii, J. Org. Chem., 32, 3948(1966). I+. K. Itoh, S. Sakai, Y. Ishii, ibid., 33, 2210 (1967). 5. K. Itoh, Y. Kato, S. Sakai, Y. Ishii, Koayo Kap,akuLasshi, ‘70, 935 (1967) and Chern.Commun.,

36(1967).