Technologies Salt and Marine Chemicals



(a) Cost effective preparation of safe brominating reagent having high atom efficiency
(b) Processes for preparation of several commercially important bromo derivatives and pharmaceutical intermediates utilizing the reagent

Inventor: G. Ramachandraiah

IPR Status: US Patent No: 6,740,253



The present invention relates to a non-hazardous brominating reagent from an aqueous alkaline bromine byproduct solution obtained from bromine recovery plant and containing 25 to 35% bromine dissolved in aqueous lime or sodium hydroxide containing alkali bromide and alkali bromate mixture having bromide to bromate stoichiometric ratio in the range of 5:1 to 5.1:1 or 2:1 to 2.1:1 and a pH ranging between 8-12 and also relates to a method for borminating aromatic compounds by using the above brominating agent.


Advantages of the invention:


(i) Inexpensive method of preparation of non-hazardous brominating reagents that are stable under storage and can be formulated either in solution or solid forms.
(ii) The alkaline bromine mixture with 5:1 bromide: bromate is a substitute for liquid bromine in bromine addition reactions and can be used for aromatic bromination reactions.
(iii) The brominating reagent with 2:1 bromide: bromate can be prepared from the alkaline bromine mixture through oxidation with inexpensive oxidizing agents and is especially suitable for aromatic bromine reactions with high Br atom efficiency that avoids the formation of HBr.
(iv) The brominating reagents are activated by simple addition of mineral acid and no catalyst is required for the bromination reactions.
(v) Bromination reaction can be carried out with the present brominating reagents under ambient conditions.

 

Technology licensed to:


Ms/ Chemcon Specialty Chemical Pvt. Ltd, Vadodara