Chemical Synthesis

DIH - Highly efficient and economical reagent for Iodination

Introduction

In 1965 Orazi et al. introduced DIH (1,3-Diiodo-5,5-dimethylhydantoin) 711624 as an efficient reagent for iodination, but only very recently has it become commercially available. DIH is a stable compound with high iodine content. Iodinations proceed smoothly in acetone. Mechanistic studies suggest that the reagent acts as an I+ donor. Homolytic cleavage could not be detected. No HI is formed. Therefore additional bases or oxidants are not required.

DIH possesses the same selectivity as NIS (N-Iodosuccinimide) and equal or better halogenating ability. With two equivalents of iodine transferred per molecule, it can be more economical in direct comparison to NIS.

References:

  1. Orazi, O.O.; Corral, R.A.; Bertorello, H.E. J. Org. Chem. 1965, 30, 1101.
  2. Ueno et al. Pharmazie 1986, 41, 10.

 

Representative Applications

DIH readily reacts in high yields with aromatic compounds that are sensitive to electrophilic substitution. Acetone proved to be a convenient solvent for this conversion keeping both the DIH and the aromatic substrate in solution. Activated substrates, such as phenol, lead directly to the triiodinated product. Attempts to iodinate a less reactive substrate, such as naphthalene, failed.

Reference:

  1. Orazi, O.O.; Corral, R.A.; Bertorello, H.E. J. Org. Chem. 1965, 30, 1101.

 

Preparation of α-Iodoketones

Like NIS, DIH can also be used for the iodination of α-iodoaldehydes and ketones. Experimental comparison of the two reagents indicates that DIH possesses the same selectivity as NIS as well as equal or better halogenating ability. The iodination can be performed in the presence of ethylenic linkages which remain intact.

Reference:

  1. Orazi, O.O.; Corral, R.A.; Bertorello, H.E. J. Org. Chem. 1965, 30, 1101.

 

Preparation of nitriles from corresponding alcohols and amines

DIH can be used as an efficient reagent for the conversion of primary alcohols, and primary, secondary, and tertiary amines into the corresponding nitriles with good yields in aqueous ammonia. In this reaction, DIH shows almost the same reactivity as molecular iodine, while it is more convenient to use.

Reference:

  1. Iida, S.; Togo, H. Synlett 2007, 3, 0407.

 

Product information

Prod. No. Product Name Structure
711624 1,3-Diiodo-5,5-dimethylhydantoin