Hydantoins: The Synthesis of 2-Thiohydantoin. [Seventh Paper.]

Johnson, Treat B.; Nicolet, Ben H.

doi:10.1021/ja02225a014

Cited by 48 publications

(18 citation statements)

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“…The idea was to r propose an alternative for chemical sequencing when N -Ter is blocked and Edman r degradation cannot be used successfully. Such a development is actually older than Edman chemistry and was proposed by Schlack & Kumpf in 1926(Schlack & Kumpf, 1926) using a reaction proposed by Johnsan & Nicolet in 1911 (Johnson & Nicolet, 1911 and on similar apparatus (Inglis, 1991;Wittmann-Liebold, Matscull, Pilling, Bradaczek, & Graffunder, 1991). Recent improvements allow secure analysis of Pro-containing peptides (Bailey, Tu, Issai, Ha, & Shively, 1994).…”

Section: Reactions Involving Free Carboxylic Groups Of Peptides/proteinsmentioning

confidence: 93%

Acceleration and Improvement of Protein Identification by Mass Spectrometry

Bienvenut¹

2005

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Section: Reactions Involving Free Carboxylic Groups Of Peptides/proteinsmentioning

confidence: 93%

Acceleration and Improvement of Protein Identification by Mass Spectrometry

Bienvenut¹

2005

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“…22 Imidazo[2,1 b][1,3,5]thiadiazines 2 (general procedure). An excess 37% formalin (3 mL) was added to a suspension of thiohydantoin derivative 1 (0.6 g, 2.9 mmol) and the corre sponding amine (2.9 mmol) in DMF (5 mL).…”

Section: Methodsmentioning

confidence: 99%

Mannich reaction in the synthesis of N,S-containing heterocycles. 1. Synthesis of novel derivatives of imidazo[2,1-b][1,3,5]thiadiazine

et al. 2005

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Reactions of (Z ) 5 benzylidene 2 thiohydantoin with formaldehyde and primary aro matic amines afforded novel derivatives of imidazo[2,1 b] [1,3,5]thiadiazine in 50-69% yields.The Mannich reaction is known to be one of the most important synthetic methods in organic chemistry. 1 At present, the great potentialities of this reaction are far from being exhausted and are still of interest for chemists. For instance, a number of recent studies are devoted to the "nonclassical" Mannich synthesis using new substrates under modified aminomethylation conditions. 2 The in tramolecular Mannich reactions 3 are of particular atten tion since they are very promising for design of novel carbo and heterocyclic systems. With the present work, we open up a series of publications concerned with the study of the structures, methods for the synthesis, and chemical transformations of nitrogen and sulfur con taining heterocyclic compounds obtained by the Mannich reaction.1,3,5 Thiadiazine derivatives belong to a promising class of heterocyclic compounds 4 with a broad spectrum of biological activities. In particular, some functionalized thiadiazines have been found to exhibit fungicidal, herbi cidal, 5,6 acaricidal, insecticidal, 7 and antibacterial prop erties. 8,9 Fused derivatives of 1,3,5 thiadiazine are most suitably synthesized by the "double" Mannich condensa tion of mercaptoazoles and mercaptoazines with forma lin and primary amines. 9-14 Earlier, we have demon strated that pyrido[2,1 b][1,3,5]thiadiazine derivatives can be obtained under the conditions of this reaction. 15 Proceeding further in those investigations, we studied condensation of easily accessible (Z ) 5 benzylidene 2 thiohydantoin (1) with formaldehyde and primary amines and found that this reaction readily occurs in boiling DMF without any catalyst to give novel imid azo[2,1 b] [1,3,5]thiadiazine derivatives (2) (Scheme 1). Scheme 1Ar = Ph (a); 4 FC 6 H 4 (b); 2 MeC 6 H 4 (c)It should be noted that the aminomethylation of thiohydantoin 1 and some of its structural analogs has been repeatedly studied earlier; 1b,16 however, we were the first to obtain imidazothiadiazine derivatives in such a way. It has been shown with a number of examples that the aminomethylation of 5,5 disubstituted 2 thiohydantoins exclusively involves the N(3) atom. 1b,16 Based on this, we assumed that the reaction intermediate is aminomethyl thiohydantoin 3, whose structure permits subsequent cyclocondensation with formaldehyde along the only possible pathway leading to imidazo[2,1 b][1,3,5]thia diazines 2. It is worth noting that documented examples * Dedicated to Academician N. S. Zefirov on the occasion of his 70th birthday.

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“…I-Acyl-2-thiohydantoins were synthesized according to the method of Johnson and Nicolet (24). and were recrystallized from methanol or ethanol.…”

Section: Methodsmentioning

confidence: 99%

Thiohydantoins. X. Kinetic Studies of the Acid Hydrolysis of 1-Acyl-2-thiohydantoins

Congdon¹,

Edward²

1972

Can. J. Chem.

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The rates of hydrolysis of 22 1-acyl-2-thiohydantoins in aqueous sulfuric acid to give 2-thiohydantoin and a carboxylic acid have been determined. In 0-90:/, sulfuric acid, hydrolysis takes place by an A-2 mechanism, and the rate reaches a maximum in about 70:! acid. In acid more concentrated than about 90%, hydrolysis takes place by an A-l mechanism, and the rate increases monotonically. Evidence for the two mechanisms comes from Yates r and Bunnett-Olsen 4 parameters; from entropies of activation; from pu and pu' relations; and from steric erects.On a determine les vitesses de I'hydrolyse de 22 acyle-l thiohydantoines-2 dans I'acide sulfurique, fournissant le thiohydanto'ine-2 et une acide carboxylique. Dans la zone de concentration de 0-90% d'acide sulfurique, la reaction se passe par un mecanisme A-2, et la vitesse de la reaction atteint un maximum dans une concentration de 70% acide environ. Entre 90-100% concentration d'acide, la reaction suit un mecanisme A-l et la vitesse de la reaction s'augmente continuellement avec la concentration d'acide. La dualite des mecanismes est supportte par: les paramttres r de Yates et 4 de Bennett et Olsen; les entropies d'activation: les relations pu ou pu' ; et les eKets steriques.

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Hydantoins: The Synthesis of 2-Thiohydantoin. [Seventh Paper.]

Cited by 48 publications

References 0 publications

Acceleration and Improvement of Protein Identification by Mass Spectrometry

Acceleration and Improvement of Protein Identification by Mass Spectrometry

Mannich reaction in the synthesis of N,S-containing heterocycles. 1. Synthesis of novel derivatives of imidazo[2,1-b][1,3,5]thiadiazine

Thiohydantoins. X. Kinetic Studies of the Acid Hydrolysis of 1-Acyl-2-thiohydantoins

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