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Novel Degradation Reactions of Halomethyl Derivatives of Bis(diacetyldioximato)cobalt.

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Novel Degradation Reactions of Halomethyl
Derivatives of Bis(diacetyldioximato)cobalt["]
New Amino Acid Derivatives from Cyanamide
and Cyanacetamide
By Gerhard N . Schrauzer, Anthony Ribeiro, Lian P . Lee, and
Raymond K . Y. Ho"]
By Joachim Gante and Giinther Mohr"'
Six to eight hours' refluxing of dimethyl cyanimidodithiocarbonate ( I a) ['I and dimethyl (u-cyanocarbamoylmethy1ene)dithiocarbonate ( I bit'] with glycine ethyl ester or
DL-methionine ethyl ester hydrochloride, respectively, and
sodium ethoxide (molar ratio 1:1:1)in anhydrous ethanol
afforded the hitherto unknown amino acid derivatives (2a)
(yield 50%, m. p. 98-99°C) and (2b) (yield 91%, oil).
Unsubstituted alkylcobaloximes['l ( I ) with, e.g., R = CH,,
which are of interest as model compounds of organocobalt
derivatives of vitamin B,,, generally exhibit a high resistance to attack by alkali. In contrast, studies on halomethyl-
R
R
/SCH~
x=C\
SCH,
(1)
I
H,N-L-C0,C2H,
-CH,SH
* x=c'
NH-CH-COZCZHS
\SCH3
(2)
(a), X = = N - C N , R = H
0
CN
(b), X
= =C'
CO-NHz, R = CHZ-CHZ-SCH,
R = CHXz (X=C1, Br, I)
(lb), R = CHZX (X=C1, Br, I)
(Ic). R = CX, (X=Cl, Br, I)
(DL-Form)
On refluxing for several hours with equimolar amounts of
primary amines in ethanol or with an excess ofconcentrated
ammonia/ethanol (2 :I), (2a) and (2b) were converted
into the respective hydantoin analogs (3) (see Table).
Cpd.
R
H2N-NH,
-
(If),
X
Yield (%)
M. p. ("C)
CH,-CH(CH,),
(CHz)5--CH,
CH,-CH,-OH
CH,-C,H5
CH2-CH,-CbH5
cyclo-C,H
H
CH,
CH,
CH(CHJz
(CHA-CH 3
CH,-C,H,
=N-CN
=N-CN
=N-CN
=N-CN
=N-CN
=N-CN
=C(CN)CONH,
=C(CN)CONH,
28
32
38
47
40
20
46
71
93
60
31
82
244-247
168-170
195-196
239
243-245
229-230
290
171-1 72
t 65- 167
128-131
155
210
Reaction of (2a) with a two- to four-fold excess of amine
under otherwise identical conditions gave the urea analogs
(4).
(2a)
( I d ) , R = CF,
( l e i , R = CH,OCH,
R'
,,
-SCH,
-SCH,
(I)
flu).
R = COOCH,
cobaloximes ( I a) -(I c ) revealed evidence for a surprisingly high alkali sensitivity. Nucleophilic attack of the
cobalt-bonded halomethyl group by OHe ion causes
initial Co-C bond cleavage to give halomethanols and
cobaloxime(1). The interesting reactions that ensue are
reported in the present communication.
In 0.1 N NaOH dihalomethylcobaloximes ( I a)['' undergo
rapid, quantitative decomposition (no isolable intermediate) into carbonylcobaloxime(I), the carbon monoxide
complex of cobaloxime(I),which is at equilibrium with free
CO and cobaloxime(1) [eq. (I)].
H,O,
H2N TN
N
>NH-CH,-CO-NH-NH,
'N
H
(51
(2a) and hydrazine hydrate (molar ratio 1:1.8 ; 2 hours'
refluxing in ethanol) furnished N-(5-amino-l,2,4-triazoI-3y1)glycine hydrazide (5) (yield 79%, m. p. 227-228 "C).
Received: July 12, 1971 [Z 485 IE]
German version: Angew. Chem. 83,886 (1971)
p] Priv.-Doz. Dr. J. Gante and Dr. G. Mohr
Forschungslaboratorien der Firrna E. Merck
61 Darmstadt, Frankfurter Strasse 250 (Germany)
[I] R. J . Timmons and L.S.Wittenbrook, J. Org. Chem. 32,1566 (1967).
[Z] R. Gompper and W Tiipfl, Chem. Ber. 95,2861 (1962).
Angew. Chem. internat. Edit. / Vol. 10 (1971) / No. 11
[*] Prof. Dr. G. N. Schrauzer, Dr. A. Ribeiro, Dr. L. P. Lee, and
Dr. R. K. Y.Ho
Department of Chemistry,
The University of California at San Diego,
Revelle College
La Jolla, Calif. 92037 (USA)
[**I This work was supported by the US Department of Health,
Education and Welfare, Grant 1-RO 1 ES 00325-01.
807
In principle, equation (1) corresponds to a conversion of
trihalomethanes into carbon monoxide catalyzed by the
nucleophilic cobaloxime(1) since dihalomethylcobaloximes
( l a ) can be prepared from cobaloxime(1) and trihalomethanes[’I.
Monohalomethylcobaloximes (1b ) [’I are cleaved by
NaOCH, in anhydrous CH,OH with intermediate formation of cobaloxime(1) and halomethyl methyl ethers. Subsequent reaction of the products in absence of air gives
methoxymethylcobaloxime ( I e ) which was isolated in
40% yield. The Co-C bond in ( I b ) is ruptured in this
case by nucleophilic attack of CH,Oe ion [eq. (2)]:
X=C1, with NaOCH, in anhydrous CH,OH gives methoxycarbonylcobaloxime (1f) in 23% yield.
The halomethyl derivatives of vitamin BIZiS1
are generally
more alkali-stable than the corresponding derivatives of
cobaloximes; however, they also decompose with Co-C
bond cleavage on heating in I N NaOH. The reactions
observed are possible prototypes for detoxification processes involving the dehalogenation of halohydrocarbons
with biogenic metal complexes as catalysts.
Received: April 22,1971 ;
revised: July 19, 1971 [Z 476 IE]
German version: Angew. Chem. 83,849 (1971)
Simple Synthesis of Pyraceheptylene and
Benzo[a]p yraceheptylene[**I
+ XCH20CH3
CH300
By Christian Jutz and Erich Schweiger“]
Of the three nonbenzenoid (nonalternant) pyrene isomers
made up only of five- and seven-membered rings and exhibiting an “aromatic” 4n+2 Hiickel perimeter-pentalen0[2.1.6-def]heptalene~~~(RE= 5.9495 p), dipleiapentalene
(RE=6.0297 p), and pyraceheptylene (1) (RE=6.0515 p)compound ( I ) appears, according to simple HMO calculations[’], to have the greatest resonance energy (RE). RE for
pyrene is 6.5055 J3.
i’Y
Decomposition of ( I b ) by aqueous alkali also proceeds
initially as shown in eq. (2). The resulting halomethanol
reacts with the cobaloxime(~),but it proved impossible to
isolate hydroxymethylcobaloxime. Instead a complicated
series of reactions ensues giving rise to cobaloxime(r1r) and
methane, as well as to traces of methanol and formaldehyde
as the final products.
Trihalomethylcobaloximes~41( I c), and ( I d ) too, also
undergo degradation with Co-C bond cleavage on treatment with alkali. Heating of ( I d ) in 2 N NaOH furnishes
cobaloxim(I), carbonate and fluoride ion. The complexes
( I c) are by far the most alkali-labile. Treatment of ( I c ) ,
[I] Cobaloximes are bis(diacety1dioximato)cobaltcomplexes; cf. G.
N . Schrauzer, Accounts Chem. Res. I , 97 (1968).
121 The halomethylcobaloximes ( I a ) , (I b ) , and ( 1 d j can be prepared by the known method [3] of reaction of di- and trihalomethanes or
CFJ with cobaloximes(1): The sole limitation is that the reaction
medium should not be too strongly alkaline, cf. Inorg. Syntheses 1 I , 61
(1968).
[3] G. N . Schrauzer, 1.H. Weber, and 7: M . Beckham, J. Amer. Chem.
SOC.92, 7078 (1970).
141 Trihalomethylcobaloximes ( I c ) are not accessible by the method
given in Ref. [2]; they are formed, however, from cobaloximes(rr) [3]
and tetrahalomethanes in CH,CI, as solvent. To prepare, e.g. ( I c ) ,
X=CI, compound ( 2 ) (10g) is suspended in CH,CI, (50 ml) with exclusion of air and the stoichiometric amount of CCI, is added slowly.
After 25 min the reaction mixture is poured into n-hexane (200 mi) and
the precipitate is filtered off. In order to isolate compound ( 3 ) , formed
according to
qc13
(2)
(Ic), x
=
c1
c1
(3)
the reaction mixture is washed with water; the insoluble residue is recrystallized from CH,CI, by addition of n-hexane. Compounds ( I c j
decompose gradually on storage and in some cases explode on heating to 120-180°C. The composition of all the new cobaloximes is
established by elemental analysis and NMR spectra.
[ 5 ] J . M . Wood, F. Scott Kennedy, and R. S. Wolfe, Biochem. 7 , 1707
(1 968).
808
A brief account of the preparation of ( I ) has been given by
Anderson‘31.We have now been able to prepare ( I ) and ( 2 )
after the manner of a Ziegler-Hafner azulene ~ynthesis‘~].
If equimolar amounts of the pentamethine salt (3)c5]and
the 6-dimethylaminovinylfulvene ( 4 ) L6] are refluxed together under N, for 24h in pyridine after addition of
NaOCH,, the pyridine distilled off in a stream of N,, and
heating to 230°C in quinoline continued until liberation of
dimethylamine ceases, the residue left when the quinoline
is distilled off in uacuo yields pure pyraceheptylene ( I ) in
5% yield on chromatography, first in methylene chloride
and then in hexane, on A1,0, (activity grade 111, neutral).
Compound ( I ) was isolated as bronze-colored platelets
(hexane), m. p. 257--259°C; UV (CH,Cl,): h,,,=484 nm
(log&=4.21);471 (3.50); 461 (3.21); 454 (3.27); 444 (3.17);
432sh (2.75); 423 (2.75); 410 (2.89); 358 (3.64); 344 (4.26);
334 (4.14); 299 (4.30); 285 (4.46); 267 (4.99); 254 (4.70).
Under the same conditions we found 2-dimethylamino-ldimethylaminopropenylidene-3-dimethylimmoniopropenylindene perchlorate ( 6 ) and cyclopentadiene to give
benzo[a]pyraceheptylene (2) in 2.5% yield. (2), blackish
brown needles (hexane),m. p. 198-200°C; UV (CH,Cl,):
h,,,=498 FUII (log&=3.84); 485 (3.98); 464 (3.66); 453
(3.54); 422 (3.09); 387 (4.28); 369 (3.94); 348 (4.06); 342 sh
(4.02); 300 (4.82); 291 sh (4.75); 286 sh (4.74); 272 sh (4.78) ;
263 (4.88); 253 (4.87); 237 (4.81).
[*] Prof. Dr. Ch. Jutz and Dip1.-Chem. E. Schweiger
Organisch-Chemisches Laboratorium der Technischen Universitat
8 Munchen 2, Arcisstrasse 21 (Germany)
[“‘I This work has been supported by the Fonds der Chemischen
Industrie and the Deutsche Forschungsgemeinschaft.
Angew. Chem. internat. Edit. / Vol. 10 11971) 1 No. I 1
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degradation, reaction, halomethyl, bis, novem, cobalt, diacetyldioximato, derivatives
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