77972-18-0Relevant academic research and scientific papers
The use of Lewis acids in the synthesis of 5-arylhydantoins
Cativiela, Carlos,Fraile, Jose M.,Garcia, Jose I.,Lafuente, Gustavo,Mayoral, Jose A.,Tahir, Rachid,Pallares, Antonio
, p. 192 - 196 (2007/10/03)
Different Lewis acids are able to promote the Friedel-Crafts reaction between 5-bromohydantoin and aromatic compounds. In the case of phenol, mixtures of ortho and para isomers are always obtained, with Mg(ClO4) 2 leading to the best selectivity. However, the best overall yield of 5-(hydroxyphenyl)hydantoin is obtained with YbCl3. This method can be extended to other aromatic systems such as anisole and thiophene. These reactions give similar yields but proceed with total selectivity to 5-(4-methoxyphenyl)hydantoin and 5-(2-thiophenyl)hydantoin, respectively. The cationic exchange of MgII and YbIII on anionic solid supports allows the preparation of very efficient heterogeneous catalysts for this reaction (productivity up to 600 mol of hydantoin per mole of Mg). These catalysts have practical advantages in that they can be recycled and reused.
Production of ring-substituted D-phenylglycines by microbial or enzymatic hydrolysis/deracemisation of the corresponding DL-hydantoins
Garcia, Maria J.,Azerad, Robert
, p. 85 - 92 (2007/10/03)
A series of 17 ring-mono and -disubstituted D-phenylglycine derivatives was prepared in high enantiomeric purity by enzymatic hydrolysis and deracemisation of the corresponding DL-hydantoins, using D-hydantoinase activities of microorganisms or purified enzymes, followed by diazotation of the resulting N-carbamyl-D-amino acids. No significant L-hydantoinase activity was found to produce the corresponding L-enantiomers.
Process for preparing 5-(4-hydroxyphenyl)hydantoin
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, (2008/06/13)
A process for preparing 5-(4-hydroxyphenyl)hydantoin by reacting glyoxylic acid, urea and phenol in an aqueous medium in the presence of an acid at an elevated temperature. The hydantoin of high purity can be readily prepared in good yields.
