- Email: [email protected]
The reaction of ionic azide with 3-halo-4-phenylcyclobutenediones a novel route to phenylcyanoketene
Tetrahedron
Letters
No.15,
pp.
1179-1180,1969.
Pergamon Press,
Printed
in Great
Britain.
THE REACTION OF IONIC AZIDE WITH 3-HALO-4-PHENYLCYCLOBUTENEDIONES A NOVEL ROUTE TO PHENYLCYANOKETENE Roy C. De Selms Research Laboratories, Eastman Kodak Company, Rochester, New York 14650, U.S.A. (Received. in USA 7 February1969; receivedin UK for publication24 February1969)
We wish to report a novel degradation leading to phenylcyanoketene (II). .At ambient temperatures, the evolution of two molar equivalents of gas (Na and CO by glc analysis)is simultaneous with the gradual addition of a X
0 +
W&s
NaN3
MeCN
>
[
ce~~;C=C=O
1
+
N2
+
CO
0
(I)
a) X
q
Br ROY
b) X = Cl
? CeHsCYzCN
NC
0 'CYC9 / 'OR CeHs
(IV) -. a)Y=H
(III) a)R-CHs,Y=H -" b)R= CzHg, Y = H c) R = CHs , Y = D
b)Y=D
solution of 3-halo-4-phenylcyclobutenedione -c\,. (I) (1) in acetonitrile to a vigorously stirred suspension of NaNs in acetonitrile, If the reaction is carried out in the presence of hydroxylic compounds (a.,
alcohols, H20) or
with their subsequent addition, products such as J&I (2) or AV arise.
This
is interpreted to mean that bond reorganization of the intermediate fragment occurs rapidly yielding I&. When the reaction is carried out in the presence of D20 or CHaOD, the cleanly deuterated products _.<.. IVb (86% yield) and 111~ (88
1179
yield), respectively,
are obtained.
However, under conditions of nonexchange, formation of g
in
CH3CN or CDsCN with subsequent addition of De0 or HeO, respectively, (30 min after cessation of gas evolutlon) leads in both cases to lower ylelds of mixtures containing equal amounts of 3
and a
with less than 10% CeHzCHDCN.
These data indicate that In the absence of ketene reactive substances, z undergoes free radical reaction and decomposition. While the competition for I-greatly favors azide ion in the presence of hydroxylic substances, more nucleophlllc agents such as amines are favored over azlde.
Thus, the amides corresponding to zcan
presence of amines.
not be prepared in the
Furthermore, free radical decomposition of g
at room
temperature apparently competes effectively with potential cycloaddition and does not lead to formation of adducts with cyclopentadiene, cyclopentene, cyclohexene, diphenylacetylene, and benzalaniline. The method described here constitutes a novel route to the rare cyanoketenes.
Only the putative formation of cyanoketene itself Is suggested in
the literature (3,4) heretofore. Footnotes and References 1.
E. J. Smutny, M. C. Caserlo, and J. D. Roberts, J. Am. Chem. Sot., g, 1793 (1960).
2.
I Ia: Analysis found: C, 69.1; H, 5.1; N, 8.3%. CloHaNOa requires: + 8.6; H, 5.2; N, 8.M. MS showed expected arent at m/e 175. Nmr at C, CDCls) exhibited singlets at 3.66 (OMeP , 4.83 (methinyl) and phenyl). IIIb: Identical to Aldrich Chemical Co., E4520-1.
3.
A. K. Bose, B. A aneyulu, S. K. Bhattacharya, and M. S. Manhas, Tetrahedron, a 4--769 (1967).
4.
cr., H. B&me,
S. Ebel, and K. Hartke, a.,
&,
1463 (1965).
Letters
No.15,
pp.
1179-1180,1969.
Pergamon Press,
Printed
in Great
Britain.
THE REACTION OF IONIC AZIDE WITH 3-HALO-4-PHENYLCYCLOBUTENEDIONES A NOVEL ROUTE TO PHENYLCYANOKETENE Roy C. De Selms Research Laboratories, Eastman Kodak Company, Rochester, New York 14650, U.S.A. (Received. in USA 7 February1969; receivedin UK for publication24 February1969)
We wish to report a novel degradation leading to phenylcyanoketene (II). .At ambient temperatures, the evolution of two molar equivalents of gas (Na and CO by glc analysis)is simultaneous with the gradual addition of a X
0 +
W&s
NaN3
MeCN
>
[
ce~~;C=C=O
1
+
N2
+
CO
0
(I)
a) X
q
Br ROY
b) X = Cl
? CeHsCYzCN
NC
0 'CYC9 / 'OR CeHs
(IV) -. a)Y=H
(III) a)R-CHs,Y=H -" b)R= CzHg, Y = H c) R = CHs , Y = D
b)Y=D
solution of 3-halo-4-phenylcyclobutenedione -c\,. (I) (1) in acetonitrile to a vigorously stirred suspension of NaNs in acetonitrile, If the reaction is carried out in the presence of hydroxylic compounds (a.,
alcohols, H20) or
with their subsequent addition, products such as J&I (2) or AV arise.
This
is interpreted to mean that bond reorganization of the intermediate fragment occurs rapidly yielding I&. When the reaction is carried out in the presence of D20 or CHaOD, the cleanly deuterated products _.<.. IVb (86% yield) and 111~ (88
1179
yield), respectively,
are obtained.
However, under conditions of nonexchange, formation of g
in
CH3CN or CDsCN with subsequent addition of De0 or HeO, respectively, (30 min after cessation of gas evolutlon) leads in both cases to lower ylelds of mixtures containing equal amounts of 3
and a
with less than 10% CeHzCHDCN.
These data indicate that In the absence of ketene reactive substances, z undergoes free radical reaction and decomposition. While the competition for I-greatly favors azide ion in the presence of hydroxylic substances, more nucleophlllc agents such as amines are favored over azlde.
Thus, the amides corresponding to zcan
presence of amines.
not be prepared in the
Furthermore, free radical decomposition of g
at room
temperature apparently competes effectively with potential cycloaddition and does not lead to formation of adducts with cyclopentadiene, cyclopentene, cyclohexene, diphenylacetylene, and benzalaniline. The method described here constitutes a novel route to the rare cyanoketenes.
Only the putative formation of cyanoketene itself Is suggested in
the literature (3,4) heretofore. Footnotes and References 1.
E. J. Smutny, M. C. Caserlo, and J. D. Roberts, J. Am. Chem. Sot., g, 1793 (1960).
2.
I Ia: Analysis found: C, 69.1; H, 5.1; N, 8.3%. CloHaNOa requires: + 8.6; H, 5.2; N, 8.M. MS showed expected arent at m/e 175. Nmr at C, CDCls) exhibited singlets at 3.66 (OMeP , 4.83 (methinyl) and phenyl). IIIb: Identical to Aldrich Chemical Co., E4520-1.
3.
A. K. Bose, B. A aneyulu, S. K. Bhattacharya, and M. S. Manhas, Tetrahedron, a 4--769 (1967).
4.
cr., H. B&me,
S. Ebel, and K. Hartke, a.,
&,
1463 (1965).