close

Вход

Забыли?

вход по аккаунту

?

Elimination of Hydrogen Sulfide with Acylated Carbodiimides General Synthesis of Aromatic and Aliphatic Carbomiimides.

код для вставкиСкачать
Elimination of Hydrogen Sulfide with Acylated
Carbodiimides:
valuable preliminary studies, was accomplished by the following route: 4 - methoxy - c?) - formylaminoacetophenone (m. p.
General Synthesis of Aromatic and Aliphatic
Carbodiimides
By Dr. K. Hartke
Central Institute of Chemistry,
University of Concepcibn (Chile)
Under extremely mild conditions, acylated, aliphatic carbodiimides (I) [l] react with many thioamides with the elimination
of hydrogen sulfide. The aliphatic carbodiimide is mixed with
the acid halide in absolute ether and is allowed to stand for
several hours. Equivalent amounts of triethylamine and thioamide are added and the mixture stirred at room temperature
for 3 to 4 hours. Triethylamine hydrochloride is filtered OK
and acylated thiourea (IV), a by-product, is shaken out with
aqueous sodium hydroxide. The reaction product is isolated
from the ether phase in very pure form.
Benzonitrile is obtained from thiobenzamide with a yield of
75 %; benzyl cyanide from phenylthioacetamide with a
yield of 7 4 % . Likewise, thiourea compounds (11) can be
converted into the corresponding carbodiimides (111).
H3C,
,CH3
,CH-N=C-N-Cy
I
,
H3C'
I
/
c1 c=o
'
CH3
+
lR2
A [21
B [31
C
D
E
phenylp-tolylphenylphenyIcyclohexyl-
phenylp-tolylisopropylmethylmethyl-
-HCI
R'-N-C-N-R2
r
I
/I
I
I1
I
% Yield
of
67
65
77
33 [b]
65
The chemical and physical properties of the compound
prepared in this manner correspond to those of (I) and the
infrared spectra are identical in every respect.
I
CHO
/
CHO
[Z 215/55 IE]
+
-~
H S H
I
93 "C) can be metalated at the methylene group with potassium t.-butoxide at and oxidatively dimerized to (11) (m.p.
241 "C) with iodine. The 1,4-diketone was reduced with sodium borohydride to the l ,4-diol (m.p. 227 "C) and the latter
was converted with phosphorus oxychloride in pyridine to
the P,v-dichlorodiisonitrile. Thereafter, the butadiene derivative was formed by double HCI elimination with KOH
in pyridine.
[*I Reported at the Siidwestdeutsche Chemie-Dozenten-Tagg,
Munich, May 24th. 1961. At the authors' request, the report was
not published. Received as a communication on February 7th.,
1962.
[l] I. Hagedorn and H . T&njes, Pharmazie IZ, 567 (1957).
[2] H . Etling, Diploma Thesis, Universitiit Freiburg i. Brsg. 1960;
I, Hagedorn and H. Etling,Angew. Chem. 73, 33 (1961).
Physical Constants of (111)
b.p. 160--162"C/0.2 mm. Hg
m.p. 55-56 "C
b.p. 106 "C/0.3mm. Hg
b.p. 93 T i 1 6 mm. Hg
% Yield
of (IV)
82
74
86
81
84
[a1 Yields refer to pure distilled products; 0.02-0.03 mole used for the
experiment; hence with larger amounts. higher yields can be expected.
Preparation and Structure of Diphenyltin
[bl Polymerizes during distillation; yield refers to urea obtained by
hydrolysis.
By Priv.-Doz. Dr. W. P. Neumann and cand. chem. K. Konig
Chemisches Institut der Universitat GieBen (Germany)
The experiments are being continued; among others, the
elimination of water from suitable compounds with the aid
of acylated carbodiimides is under investigation.
Received, February 5th. 1962
[Z 213/50
IE]
[l] K . Hartke and J. Bartulin, Angew. Chem. internat. Edit. I,
211 (1962).
[2] C. Schall and S . Paschkowetzky, Ber. dtsch. chem. Ges. 25,
2886 (1892); R. Stolli, ibid. 41, 1125 (1908).
[3] F. Zetzsche et al., Ber. dtsch. chem. Ges. 71, 1513 (1938); 72,
364 (1939); 73, 474 (1940).
Synthesis of Xanthocillin Dimethyl Ether
By Dr. Ilse Hagedorn and Dr. U. Eholzer
[*I
Chemisches Laboratorium der Universitat Freiburg/Brsg.
(Germany)
The structure of t h e surface antibiotic xanthocillin has b e e n
established t h r o u g h its m o r e stable dimethyl ether (I), [l].
The t o t a l synthesis, to w h i c h H . Etling [21 has contributed
212
It has been recently reported that "diethyltin" has a ring
structure [I]. We have now been able to show that polymeric diphenyltin, formed in the reaction of numerous amines
with diphenyltin dihydride, also has a ring structure. At 20 "C
the pentamer (I) is obtained in a good yield with dimethylformamide, while the hexamer (11) is the predominant product
in the reaction with pyridine. Compounds (I) and (11) crystallize from toluene as colorless, rectangular plates which release
the bound solvent on heating in vacuo and which decompose
above 270 "C. Correct molecular weight determinations were
carried out using a thermistor osmometer. (C6HS)zSn groupings are the only components, as shown by degradation with
iodine and analysis of the cleavage products [2,3]. The
predominant product formed from diphenyltin dihydride
in methanol is the solid linear organotin hydride (111) (Sn-H
absorption at 1790 cm.-1), rather than a modification of
diphenyltin [4].At 20 "C the hydride (111) looses H2 and is
converted into (II) by the action of pyridine or other
amines.
Dimetbyl5 RzSnH2
~
+
formamide
p
Rv R,
s
q
,
,SnRz
5 H 2 + R2Sn
R = GHs
Sll
Rz
Angew. Chem. internat. Edit.
(1)
/ VoI. I
(1962)/ No. 4
Документ
Категория
Без категории
Просмотров
0
Размер файла
111 Кб
Теги
elimination, hydrogen, carbodiimide, synthesis, sulfide, acylated, general, aliphatic, aromatic, carbomiimides
1/--страниц
Пожаловаться на содержимое документа