Thiohydantoins. III. Anhydride Intermediates in the Formation of 1-Acyl-2-thiohydantoins from Acylamino Acids

1952 ◽  
Vol 5 (4) ◽  
pp. 728
Author(s):  
JM Swan
Keyword(s):  
Carbon Dioxide ◽  
Acetic Acid ◽  
Acetic Anhydride ◽  
Hippuric Acid ◽  
Ammonium Thiocyanate ◽  
High Yield ◽  
Mixed Anhydride

Linear anhydrides are formed by the action of acetic anhydride on p-toluene-sulphonylglycine and carbobenzyloxy-glycine, -phenylalanine, and -β-alanine. The anhydrides from the first two acids yield the corresponding 2-thiohydantoin with ammonium thiocyanate in acetic acid. Other methods for the preparation of l-p-toluenesulphonylglycine anhydride, and its 2-thiohydantoin, are also given. Hippuric acid, with ethyl chlorocarbonate and triethylamine yields ethyl hippurate, probably via the mixed anhydride and 2-phenyloxazol-5-one. The inclusion of ammonium thiocyanate gives 1-benzoyl-2-thiohydantoin in high yield. The N-carboxy anhydride of phenylalanine (4-benzyloxazolid-2,5-dione) also reacts with ammonium thiocyanate to give carbon dioxide and 5-benzyl-2-thiohydantoin.

Studies in Thiohydantoin Chemistry. I. Some Aspects of the Schlack-Kumpf Reaction

1996 ◽  
Vol 49 (5) ◽  
pp. 541 ◽  
Author(s):  
BM Duggan ◽  
RL Laslett ◽  
JFK Wilshire
Keyword(s):  
Amino Acids ◽  
Acetic Acid ◽  
Acetic Anhydride ◽  
Ammonium Thiocyanate ◽  
Sodium Thiocyanate ◽  
Side Chains ◽  
Derivatives Of

An investigation has been carried out into the Schlack-Kumpf reaction, i.e., the reaction of amino acids with a mixture of acetic anhydride, acetic acid and sodium thiocyanate (occasionally ammonium thiocyanate was used). Particular emphasis was placed on the reactions with amino acids containing sensitive or functional side chains, i.e., serine, threonine , arginine , proline , lysine, histidine , cysteine , and aspartic and glutamic acids. The reaction of serine, and of certain of its O- and N-substituted derivatives, takes an unusual course to give an acetylated thiohydantoin derivative of cysteine. Correspondingly, threonine gives an acetylated thiohydantoin derivative of β- methylcysteine. Similar reactions occurred with the 3-phenylthiohydantoin derivatives of serine and of threonine to give acetylated thiohydantoin derivatives of cysteine and of β-methylcysteine respectively.

Hot-Tube Reactions of Dehydroabietic Acid with Ketene-Producing Reagents. Pyrolysis of the Acid Chloride and Symmetrical and Mixed Anhydride Derivatives of Dehydroabietic Acid

1973 ◽  
Vol 51 (19) ◽  
pp. 3236-3241 ◽  
Author(s):  
Ray F. Severson ◽  
Walter H. Schuller
Keyword(s):  
Acetic Acid ◽  
Acetic Anhydride ◽  
Acid Chloride ◽  
Acetyl Chloride ◽  
Dehydroabietic Acid ◽  
Mixed Anhydride ◽  
Temperature Range ◽  
Acid Isomerization ◽  
Derivatives Of ◽  
Isopropenyl Acetate

Dehydroabietic acid (1a) was reacted with diketene, acetic acid, acetic anhydride, isopropenyl acetate, acetyl chloride, and acetone on Vycor rod at 450 °C in a hot tube. Dehydroabietic anhydride (1b) and acetyl dehydroabietate (1c) were pyrolyzed at 450 °C and dehydroabietyl chloride (1d) was pyrolyzed over a temperature range of 290–500 °C. The major olefin products resulting from decarboxylation of the various derivatives were 19-norabieta-4,8,11,13-tetraene (2), 19-norabieta-4(18),8,11,13-tetraene (3), 19-norabieta-3,8,11,13-tetraene (4), and cis-1,10a-dimethyl-7-isopropyl-1,2,3,9,10,10a-hexahydrophenanthrene (5). High conversions to these compounds were obtained. In the presence of the ketene-producing reagents the olefins were oxidized to yield substantial amounts of retene (6), compounds 2 and 5 being the most readily dehydrogenated. The acid isomerization of 2, 3, 4, and 5 was studied using p-toluenesulfonic acid in toluene at 110 °C.

Photochemical reactions of azo compounds. VII. Studies of the photochemical reactions of azobenzene under various acidic conditions

1966 ◽  
Vol 19 (8) ◽  
pp. 1445 ◽  
Author(s):  
GE Lewis ◽  
RJ Mayfield
Keyword(s):  
Acetic Acid ◽  
Acetic Anhydride ◽  
Sulphuric Acid ◽  
Photochemical Reaction ◽  
Acetyl Chloride ◽  
Photochemical Reactions ◽  
Aluminium Chloride ◽  
Azo Compounds ◽  
High Yield ◽  
Acidic Conditions

An investigation has been made of the photochemical and dark reactions of azobenzene in acetic acid-ferric chloride and acetic acid-aluminium chloride mixtures for comparison with the corresponding reactions of azobenzene in sulphuric acid. The photochemical reactions resulted in cyclodehydrogenation of azobenzene to benzo[c]cinnoline, and small quantities of reduction products of azobenzene were also isolated. The formation of reduction products was again observed in the dark reactions, but there was no sign of cyclodehydrogenation. The significance of these observations is now discussed. Irradiation of azobenzene in acetyl chloride, or in acetic anhydride containing hydrogen chloride, resulted in a novel photochemical reaction in which NN?-diacetyl-4-chlorohydrazobenzene was formed in high yield.

An unusual reaction of a bridged triterpenoid α-diketone with acetic anhydride

1991 ◽  
Vol 56 (12) ◽  
pp. 2917-2935 ◽  
Author(s):  
Eva Klinotová ◽  
Václav Křeček ◽  
Jiří Klinot ◽  
Miloš Buděšínský ◽  
Jaroslav Podlaha ◽  
...  
Keyword(s):  
Acetic Acid ◽  
Nmr Spectroscopy ◽  
Acetic Anhydride ◽  
Spectral Methods ◽  
X Ray Diffraction ◽  
X Ray ◽  
Mild Conditions ◽  
Condensation Products ◽  
Unsaturated Lactones ◽  
C Nmr

3β-Acetoxy-21,22-dioxo-18α,19βH-ursan-28,20β-olide (IIIa) reacts with acetic anhydride in pyridine under very mild conditions affording β-lactone IVa and γ-lactones Va and VIIa as condensation products. On reaction with pyridine, lactones Va and VIIa undergo elimination of acetic acid to give unsaturated lactones VIIIa and IXa, respectively. Similarly, the condensation of 20β,28-epoxy-21,22-dioxo-18α,19βH-ursan-3β-yl acetate (IIIb) with acetic anhydride leads to β-lactone IVb and γ-lactone Vb; the latter on heating with pyridine affords unsaturated lactone VIIIb and 21-methylene-22-ketone Xb. The structure of the obtained compounds was derived using spectral methods, particularly 1H and 13C NMR spectroscopy; structure of lactone IVa was confirmed by X-ray diffraction.

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