One-step liquid-phase heterogeneous synthesis of phenytoin using modified calcium oxide as a solid basic catalyst

Synthesis of benzoin under supramolecular catalysis involving cyclodextrins in water: application for the preparation of the antiepileptic drug phenytoin

Among the cyclodextrins screened for the synthesis of 2-hydroxy-1,2-diphenylethanone (benzoin) in water, 2-hydroxypropyl-β-cyclodextrin (HP-β-CD) exhibited the highest yield in the benzoin condensation reactions, and HP-β-CD can be recycled several times with little loss of activity through the addition of fresh VB₁. As an example of supramolecular catalysis, the methodology was applied to the “green” synthesis of the antiepileptic drug phenytoin through benzoin condensation, oxidation, and cyclization reactions in the presence of HP-β-CD, without the use of any harmful organic solvent. Moreover, the complexation behaviors of HP-β-CD with benzaldehyde and intermediates were studied by UV-vis and 2D-ROESY NMR spectroscopies to reveal the plausible mechanisms of the reactions, and HP-β-CD did not act as a simple phase transfer agent.

Benzoin was synthesized using cyclodextrins as phase transfer catalysts. As an example of supramolecular catalysis, the methodology was applied to the “green” synthesis of the antiepileptic drug Phenytoin in the presence of HP-β-CD.

Designed Synthesis of Diversely Substituted Hydantoins and Hydantoin-Based Hybrid Molecules: A Personal Account

Hydantoin and its analogues such as thiohydantoin and iminohydantoin have received substantial attention from both a chemical and a biological point of view. Several compounds of this class have shown useful pharmacological activities such as anticonvulsant, antitumor, antiarrhythmic, and herbicidal properties that have led, in some cases, to clinical applications. Because of these broad-spectrum activities, intensive research efforts have been dedicated in industry and academia to the synthesis and structural modifications of hydantoin and its derivatives. Realizing the importance of hydantoin in organic and medicinal chemistry, we also initiated a research program that successfully designed and developed new routes and methods for the formation of hydantoin, thiohydantoin, and iminohydantoin substituted at various positions, particularly at the N-1 position without following a protection–deprotection strategy. Because combinations of two or more pharmacophoric groups can lead to hybrid molecules that display a mixed mechanism of action on biological targets, we extended our developed strategy to the syntheses of new types of hydantoin-based hybrid molecules by combining hydantoin with a triazole, isoxazoline, or phosphate scaffold as a second pharmacophore to exploit their diverse biological functions.

1 Introduction

2 Chemistry and Properties

2.1 Physical Properties

2.2 Chemical Properties

2.3 Biological Properties

3 General Synthetic Methods

4 Synthesis of Diversely Substituted Hydantoins

5 Synthesis of Diversely Substituted Thiohydantoins

6 Synthesis of Diversely Substituted Iminohydantoins

7 Fused or Bicyclic (Thio)hydantoins

8 Di- or Multivalent (Thio)hydantoins

9 Hydantoin-Based Hybrid Molecules

9.1 Hydantoin–Isooxazoline Hybrids

9.2 Hydantoin–Triazole Hybrids

9.3 Hydantoin–Phosphate Hybrids: Phosphorylated Hydantoins

10 Summary and Outlook

Recent Advances in the Synthesis of Hydantoins: The State of the Art of a Valuable Scaffold

The review highlights the hydantoin syntheses presented from the point of view of the preparation methods. Novel synthetic routes to various hydantoin structures, the advances brought to the classical methods in the aim of producing more sustainable and environmentally friendly procedures for the preparation of these biomolecules, and a critical comparison of the different synthetic approaches developed in the last twelve years are also described. The review is composed of 95 schemes, 8 figures and 528 references for the last 12 years and includes the description of the hydantoin-based marketed drugs and clinical candidates.