The aminobarbituric acid-hydantoin rearrangement
| Autor: | Michael Gütschow, Manuela Meusel, Agnieszka Ambrozak, Thomas Hecker |
|---|---|
| Rok vydání: | 2003 |
| Předmět: |
Reaction mechanism
Magnetic Resonance Spectroscopy Alkylation medicine.drug_class Hydantoin Carboxamide Chemical synthesis Medicinal chemistry chemistry.chemical_compound medicine Organic chemistry Combinatorial Chemistry Techniques Rearrangement reaction Amines Molecular Structure Chemistry Hydantoins Organic Chemistry Halogenation General Medicine Bucherer–Bergs reaction Cyclization Barbiturates Hydantoin derivatives Amine gas treating Chromatography Thin Layer |
| Zdroj: | The Journal of organic chemistry. 68(12) |
| ISSN: | 0022-3263 |
| Popis: | A general synthesis protocol for the generation of tri- and tetrasubstituted 5-carbamoylhydantoins is described. Starting from barbituric acids and following bromination and reaction with primary amines, 5-aminobarbituric acids 3a-s and 8 were prepared. Compounds 3 and 8 were subjected to different conditions of a base-catalyzed rearrangement reaction to yield the 1,5,5-trisubstituted hydantoins 4a-s and the 1,3,5,5-tetrasubstituted hydantoin 5c, respectively. Alkylation of 4a-s afforded 1,3,5,5-tetrasubstituted hydantoins 5a-h. Mechanisms that explain the transformation of corresponding aminobarbituric acids to hydantoins 4a-s and 5c were discussed in terms of the formation of ring-opened intermediates. Aminobarbituric acids 3a-s unsubstituted at position 3 underwent a ring contraction via intermediate isocyanates which were trapped by the amino function. A different mechanism involving a carbamate intermediate was concluded for conversion of the 1,3,5,5-tetrasubstituted aminobarbituric acid 8. |
| Databáze: | OpenAIRE |
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