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.

N-Methylamino Acids in Peptide Synthesis. II. A New Synthesis of N-Benzyloxycarbonyl, N-Methylamino Acids

1973 ◽  
Vol 51 (12) ◽  
pp. 1915-1919 ◽  
Author(s):  
John R. McDermott ◽  
N. Leo Benoiton
Keyword(s):  
Amino Acids ◽  
Methyl Iodide ◽  
Peptide Synthesis ◽  
Side Chains ◽  
Butyl Group ◽  
New Synthesis ◽  
Derivatives Of

Reaction of N-benzyloxycarbonyl derivatives of aliphatic amino acids, and threonine, aspartic, and glutamic acids whose side-chains were protected with the t-butyl group, gave the corresponding N-methylamino acid derivatives in good yields. The methionine derivative could be obtained by using only one mol of methyl iodide. Derivatives of threonine, and aspartic and glutamic acids whose side-chains were not protected could not be methylated. Analysis of the crude products of methylation in three cases showed that they contained 0–1% of racemized material.

Thiohydantoins. II. Thiohydantoins Derived from Aspartic and Glutamic Acids

1952 ◽  
Vol 5 (4) ◽  
pp. 721
Author(s):  
JM Swan
Keyword(s):  
Acetic Anhydride ◽  
Carboxylic Acids ◽  
Ammonium Thiocyanate ◽  
Derivatives Of ◽  
Isomeric Pairs ◽  
Acyl Derivatives

N-Acyl derivatives of the &carboxylic acids, aspartic and glutamic acids, yield the corresponding anhydrides when heated with acetic anhydride in the presence or absence of ammonium thiocyanate. In general these anhydrides form isomeric pairs of amides and anilides, and only one of each pair can be converted into the corresponding 2-thiohydantoin. The anhydrides from N-phenylacetyl- and N-p-nitro-benzoylglutamic acids, and N-acetylaspartic acid have been regarded hitherto as oxazolones.

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.

Nitration of 3,4-Dimethylacetophenone and 3,4-Dimethylbenzophenone. Formation and Rearomatization of Adducts

1975 ◽  
Vol 53 (11) ◽  
pp. 1570-1578 ◽  
Author(s):  
Alfred Fischer ◽  
Colin Campbell Greig ◽  
Rolf Röderer
Keyword(s):  
Acetic Acid ◽  
Acetic Anhydride ◽  
Nitro Group ◽  
Nitrous Acid ◽  
Main Product ◽  
Intermediate Formation ◽  
Nitro Derivatives ◽  
Acidic Conditions ◽  
Cis And Trans ◽  
Derivatives Of

Nitration of 3,4-dimethylacetophenone in acetic anhydride gives a mixture of cis-and trans-2-acetyl-4,5-dimethyl-4-nitro-1,4-dihydrophenyl acetate as the main product, together with 3,4-dimethyl-2-, 3,4-dimethyl-5-, and 3,4-dimethyl-6-nitroacetophenone. Analogous products are obtained from 3,4-dimethylbenzophenone. Rearomatization of the adducts under mildly acidic conditions occurs via 1,4-elimination of nitrous acid to form 2-acetyl- and 2-benzoyl-4,5-dimethylphenyl acetate, respectively. In strongly acidic conditions elimination of acetic acid accompanied by 1,2- and 1,3-shifts of the nitro group occurs to form the 2- and 5-nitro derivatives of the parent ketones. The rearomatization to the nitro derivatives involves the intermediate formation of an ipso-cyclohexadienyl cation which may be trapped by anisole or mesitylene to form biphenyl derivatives.

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.

Thiohydantoins. I. The Preparation of Some 2-Thiohydantoins from Amino Acids and Acylamino Acids

1952 ◽  
Vol 5 (4) ◽  
pp. 711 ◽  
Author(s):  
JM Swan
Keyword(s):  
Amino Acids ◽  
Acetic Anhydride ◽  
Ammonium Thiocyanate ◽  
Acyl Derivatives ◽  
Degradation Of Peptides

A reinvestigation of the stepwise degradation of peptides and proteins by the Schlack and Kumpf (1926) procedure, which involves conversion of the terminal carboxyl residue to a 5-substituted-2-thiohydantoin; has been undertaken. The following amino acids or their aoetyl derivatives have been converted by warming with acetic anhydride and ammonium thiocyanate into the corresponding 1-acetyl-2-thio-hydantoins: valine, methionine, isoleucine, α-aminophenylacetic acid, tryptophane, histidine, and tyrosine. These new 1-acetyl-2-thiohydantoins, as well as others, have been deacetylated by an improved procedure. Certain 1-acyl-5-carbethoxy-2-thio- hydantoins on hydrolysis give 2-thiohydantoin only. N-acetylthreonine, acetic anhydride, and ammonium thiocyanate produce 5-ethylidene-2-thiohydantoin, also obtained by the condensation of acetaldehyde with 2-thiohydantoin or its 1-acyl derivatives, or from the interaction of ammonium thiocyanate with 2-phenyl-4-ethylideneoxazol-5-one. This type of rearrangement occurs in other cases.

scholarly journals The application of ketimine derivatives of amino acids to peptide synthesis

1976 ◽  
Vol 29 (7) ◽  
pp. 1591 ◽  
Author(s):  
AP Hope ◽  
B Halpern
Keyword(s):  
Amino Acids ◽  
Acetic Acid ◽  
Amino Acid ◽  
Biologically Active ◽  
Amino Acid Esters ◽  
Protecting Group ◽  
Active Peptides ◽  
Biologically Active Peptides ◽  
Derivatives Of ◽  
Acid Esters

N-(2-Hydroxyarylmethy1ene)amino acids have been coupled with amino acid esters to form sterically pure N-protected dipeptide esters. The protecting group can be removed by means of 80% acetic acid under conditions which leaves the t-butyloxycarbonyl protecting group intact. Biologically active peptides which are C-terminal partial sequences of substance P were prepared and were shown to have the expected vasodilator, spasmogenic and venoconstrictor properties.

Reactions of Amino Acids on 2-Methylmercaptohydantoin Derivatives. Synthesis of Imidazoimidazoline and Imidazoquinazoline Derivatives

1981 ◽  
Vol 36 (3) ◽  
pp. 366-369 ◽  
Author(s):  
H. A. Daboun ◽  
A. M. Abd-Elfattah ◽  
M. M. Hussein ◽  
A. F. A. Shalaby
Keyword(s):  
Amino Acids ◽  
Acetic Acid ◽  
Acetic Anhydride ◽  
Anthranilic Acid

Treatment of 5-arylidene-2-methylmercaptohydantoins (1a-d) and 5-arylazo-2-methyl- mercaptohydantoins (3a, b) with glycine in acetic acid gave 5-arylidene-N2-carboxy- methylglycocyamidines (2a-d) and 5-arylazo-N2-carboxymethylglycocyamidines (4a, b) respectively. 2 a, b, d were cyclised with acetic anhydride to give imidazoimidazoline derivatives (5a-c). 2-Methylmercapto-3-phenylhydantoin (7) reacted with anthranilic acid to give 9 which previously prepared by the action of aniline on ethyl 2-methylthio-4-oxo- 3,4-dihydro-3-quinazolinylacetate (8). Arylidenes 1 a-c, 10 a-c and arylazo derivatives 3 a, b reacted with anthranilic acid to give imidazoquinazoline derivatives 11a-f and 12 a, b, respectively.

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