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Trisubstituted Formamidines.

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(CzHdzNH, sulfur (Sl to SS), SO2, SO, and HzO. These
properties would be expected for a substance having structure A or B. The I R spectrum shows a sharp band at 2440
(C zH5)zNSOH '/z HzO
0
0
(C zH,) 2yS09*.HOH.- %ST( C ~€3,)
H
H
(B)
(A)
8
cm-1 corresponding t o -NHR2, thus suggesting the betaine
structure B. B is therefore the first stable derivative of an Nsulfoxylic acid.
N-Thioformylpyrrolidine (2d) and pyrrolidiniurn N-pyrrolidinedithiocarboxylate (3d) :
T o a 37% aqueous solution of formaldehyde (15 g, 0.5 mole)
are added first pyrrolidine (35.5 g, 0.5 mole), with ice cooling,
and then sulfur (48 g, 1,5 mole), water (35 ml), and ethanol
(100 ml); the mixture is subsequently refluxed for 4 h. The
excess of sulfur is filtered off and, after removal of ethanol,
the filtrate is extracted with ether. Distillation of the ether
extract affords (2d) (9 g, IS%), b.p. 100-1lO"Cjl torr, m.p.
32-33 "C (b.p. 157-160 OC/16 torr, m.p. 31.5-32.5 O C ,
according to ref. [71).
Concentration of the aqueous phase yields ( 3 d ) (7 g, 13%),
m.p. 156-158"C, together with 20 g of a black greasy
substance.
Received: December 3, 1968
[Z 920 IE]
German version: Angew. Chem. X I , 154 (1969)
[*I Dr. Ludwig Maier
Monsanto Research S.A.
CH-8050 Zurich, Eggbiihlstrasse 36 (Switzerland)
111 K . Kindler, Liebigs Ann. Chem. 431, 187 (1923).
[2] D . A . Peak and F. Stansfield, J. chem. SOC.(London) 1952,
4067.
[3] L. Cavalieri, D . B. Pattison, and M. earmark, J. Amer.
chem. SOC.67, 1783 (1945).
[4] F. H. McMillan and J . A . King, J. Amer. chem. SOC.70,4143
(1948).
[51 F. Asinger and H. Ofermanns, Angew. Chem. 79,953 (1967);
Angew. Chem. internat. Edit. 6, 907 (1967).
161 L. Maier, Angew. Chem. 77, 549 (1965); Angew. Chem.
internat. Edit. 4, 527 (1965); Helv. chim. Acta 50, 1723 (1967);
51, 1608 (1968).
[7] W . Walter and G. Maerten, Liebigs Ann. Chem. 712, 58
(1968).
By J. Tillack and Renate Kaiser[*]
In connection with investigations on the reactions occurring
in halogen incandescent lamps we were able t o synthesize
WOBr3rIl; we have now also succeeded in preparing the
hitherto unknown compound WOBr2.
Tungsten, tungsten trioxide, and bromine (molar ratio 2:1:3)
were transferred t o an evacuated sealed tube (length 180 mm,
diameter 25 mm) and placed in a temperature gradient of
of 450/ca. 4OoC in such a way that the W/WO3 was in the
hotter half and the bromine in the cooler half of the slightly
inclined tube. After about 30 min almost all of the bromine
had reacted with part of the other components t o give higher
tungsten bromides and oxide bromides, so that further reaction could be carried out in a temperature gradient of 580/
450 ' C without danger of explosion.
+ WO3 + 3 Brz +
3 WOBrz
(1
The WOBr2, which is formed in the hot zone, was deposited
by a chemical transport process (21 - probably in accord with
equation (2) - in the cooler half of the tube (45OOC) in the
form of well-crystalline, grayish black lustrous needles.
142
+ WOBr4, g
i
'
2 WOBr3, g
(2)
A slight excess of bromine (3-5 mg more bromine per ml of
tube volume than required stoichiometrically) prevents dissociation of the WOBr2 deposited. With a stoichiometric
charge of 20 mg-atoms of tungsten, 10 mmoles of W 0 3 , and
30 mmoles of bromine the above procedure afforded 10.2 g
of WOBr2 (yield ca. 95 %; regarding analytical procedures,
see refs. [1,31).
Owing t o the reversibility of the reaction, WOBrz may also
be prepared from tungsten and oxygen or WOz, and bromine.
In a temperature gradient of 550/470 O C the mixture described
repeatedly gave large amounts of a dull, blue-black substance at 470°C, which has the approximate composition
W203Br3 and which clearly differed in its chemical behavior
and X-ray diffraction pattern from WOBr2; this substance
has not yet been investigated further.
When dry WOBr2 is heated in a test tube yellowish brown
fumes of W02Br2 with a little bromine are evolved and W 0 3
is left behind as residue. No reaction is observed between
WOBrz and water or dilute acids (HCI, HzSO4, CH3COOH)
at room temperature; when heated to boiling with water,
conc. hydrochloric acid, or dilute acetic acid nothing more
than a slight blue coloration is noted, whereas conc. sulfuric
acid and conc. nitric acid decompose WOBr2.
The compound is attacked neither by cold nor by hot aqueous ammonia. However, treatment with 2 M NaOH yields a
voluminous, blackish brown precipitate that was not examined further. In both cases, subsequent addition of approximately 3 % H202 gives clear yellow solutions.
At room temperature WOBrz decolorizes a KMn04 solution
that has been acidified with sulfuric acid. Organic solvents,
e.g. ethanol, acetone, toluene, dichlorobenzene, and trichloroethylene, do not have any effect on the compound.
Regarding the X-ray characterization of WOBrz, we report
the following d values and the estimated intensities (in parentheses) of the first reflections up to 8 = 38 O :
7.31 (3); 6.55 (8); 3.63 (10); 2.68 (8); 2.36 (4); 2.22 (1); 2.19 (1);
2.08 (2); 2.00 (7); 1.89 (5); 1.71 (1); 1.68 (2); 1.64 (1); 1.55 (5);
1.43 (I); 1.26 (2).
The density was determined pycnometrically in toluene at
25.0 & 0.1 O C as 6.13 g/cm3.
Received: November 28, 1968
[Z 927 IE]
German version: Angew. Chem. X I , 149 (1969)
[*I Dr. J. Tillack and Renate Kaiser
Tungsten(1v) Oxide Bromide, WOBr,
2W
WOBrz
Philips Zentrallaboratorium GmbH
Laboratorium Aachen
51 Aachen, Postfach 450 (Germany)
[l] J . Tiliack and R . Kaiser, Angew. Chem. 80, 286 (1968);
Angew. Chem. internat. Edit. 7, 294 (1968).
[2] H. Schufer: Chemische Transportreaktionen. Verlag Chemie,
Weinheim 1962.
[ 3 ] H . Schafer and K . D. Dohmann, Z . anorg. allg. Chem. 300, 1
(1959); J . Tifluck, Z. analyt. Chem. 239, 81 (1968).
Trisubstituted Formamidines
By M . F. G . Stevens and A . Kreutzberger[*l
The aminomethinylation reaction that takes place on nucleophilic attack of s-triazine ( I ) on amines (2) "1 can be utilized
in a new synthesis of aminoquinazolinesrz]. The ease of this
additive cyclization decreases as the basic strength of the
amino group in (2) decreases, so that 2-amino-5-nitrobenzonitrile does not react with ( I ) under the conditions used,
even in pyridine. By contrast, reaction occurs with violent
evolution of ammonia when the starting materials are heated
in piperidine; however, the reaction course deviates from that
Angew. Chem. internat. Edit, f Vol. 8 (1969) f No. 2
of aminoquinazoline formation. The base peak at m , e 84
and the fragment ions observed in the mass spectrum of the
end product at m / e 69,56,41, 30, and 28 are analogous to the
fragments formed by formimidoylpiperidine groups [31. On
the basis of this fragmentation pattern and the molecular ion
observed at m / e 258, and in accord with other spectroscopic
and chemical data, the reaction product was identified as
1- [N-(2-cyano-4-nitrophenyl)formimidoyl]piperidine
(47).
This reaction proves to be very amenable to variation and
represents a general method for the preparation of NZ-arylN1,N1-dialkylformamidines ( 4 ) , in which R4 and R5 can also
be parts of a heterocyclic ring.
Attack of ( I ) on CH-acids, such as 4-nitrophenylacetonitrilec31 and a-picoline N-oxideC41. in the presence of secondary amines is a reaction comparable to the formation of
( 4 ) . The class of trisubstituted formamidines contains representatives having ovicidal[51, herbicidal 161, antiviral, and
antibacterial [71 activity.
[ S ] V. Diftrich, J . econ. Entomol. 60, 13 (1967).
161 H. J . Gerjovich US-Pat. 3189648 (1965); Chem. Abstr. 63,
9959h (1965).
[7] N . Steiger, US-Pat. 3135755 (1964); Chem. Abstr. 65, 7094b
(1966).
Solvolytic Ring Expansion in a Transition Metal
it-Complex (1 I
By G. E. Herberich and J . Schwnrzer[*]
Alkyl halides and esters that carry a ferrocenyl group or a
similar complex substituent in the =-position undergo solvolysis as1readily as triphenylmethyl halides and esters 12731.
The intermediateTcarbonium ion is stabilized byithezneighboring group effect of the complex substituent, the nonbonding-d:electrons of the centrallatomIor ion seemingly
do+ x-
CO
i
(la): X
(lbj: X
=
Br
=
I
(2a): X
(26): X
=
Br
= I
R3
CEN
H
NO2
NO1
H
H
H
H
H
H
H
H
H
H
H
NO2
H
H
H
H
H
H
NO2
CEN
Not
H
H
NOz
OH
C1
H
NO2
NO2
75
70
90 (oil)
95 (oil)
7s
136-137 [a]
53-54 [b]
108-110 [a]
62-63 [b]
57-58 [b]
79-80 [b]
176-178 [c]
193-194 [dl
182-183 [el
112-113 [b]
61-62 [b]
[a1 Recrystallized from benzene/light petroleum; [b] from ether/light petroleum;
It1 from ethanol; [dl from ethanol, m.p. of the picrate; [el from ethanol/ether, m.p. of
the tosylate.
4-[N-(4-Nitrophenyl)formimidoyll morpholine (4j)
Rapid evolution of ammonia occurs when a mixture of striazine ( I ) (1.6 g, 0.02 mole) and 4-nitroaniline (2j) (5.5 g,
0.04 mole) in morpholine (13.1 g, 0.15 mole) is heated to
boiling. After 2 hours' heating and subsequent cooling, compound (4j) (8 g, 85 %) is isolated by vacuum concentration:
112-113 OC, after recrystallization
m.p. and mixed m.p.
from etherllight petroleum.
Received: December 18, 1968
[Z 921 IE]
German version: Angew. Chem. 81, 154 (1969)
[*] Dr. M. F. G. Stevens
Department of Pharmacy
Heriot-Watt University
79 Grassmarket, Edinburgh 1 (Great Britain)
Prof. Dr. A. Kreutzberger
Institut fur pharmazeutische Chemie der Universitdt
44 Miinster, Hittotfstr. 58-62 (Germany)
111 A. Kreutzberger, Fortschr. chem. Forsch. 4 , 273 (1963).
[2] M . F. G. Stevens and A . Kreutzberger, Angew. Chem. 81, 84
(1969); Angew. Chem. internat. Edit. 8, 73 (1969).
[3] A . Kreutzberger and D . Abel, Arch. Pharmaz. 301, 881
(1968).
141 A . Kreutzberger and D. Ahel, Arch. Pharmaz. 302 (1969),
in press.
Angew. Chem. internat. Edit. 1 Vol. 8 (1969) No. 2
playing a key role in this stabilization [31, Ligand rearrangements have not hitherto been observed during solvolyses of
this kind.
We now wish to report on a novel type of an exceptionally
rapid solvolysis. The 5-exo-halogenomethyl derivatives ( 1 ) [41
of cyclopentadienecyclopentadienyicobalt,which are stable
in hexane solution, rearrange irreversibly in polar media to
give cyclohexadienylcyclopentadienylcobaltsalts (2).
This is the first example of a solvolytic ring expansion in a
ligand of a transition metal r-complex.
The solvolysis of ( l a ) can readily be followed by spectrophotometric techniques: the reaction is first order with
respect to ( l a ) ; a rate constant of kl = 1.1 x 10-4 sec-1 was
found at 30 "C in ethanol/n-hexane (95:5). By contrast, compound ( I b ) rearranges in the solid state at O°C almost
quantitatively to ( 2 b ) within two days.
The salts of the cyclohexadienylcyclopentadienylcobalt
cation {Z), which has now been obtained for the first time,
are red, air-stable substances that are somewhat sensitive to
light; the composition of the iodide and of the hexafluorophosphate were established by elemental analysis. The constitution of the cation is evidenced by the 'H-NMR (see
Table 1) and by the IR spectrum. The IH-NMR spectrum
143
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