2369-34-8Relevant academic research and scientific papers
Method for photocatalytic synthesis of polybrominated phenol compound in water phase
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Paragraph 0012; 0029, (2019/08/30)
The invention discloses a method for photocatalytic synthesis of a polybrominated phenol compound in a water phase, comprising the following steps: adding a catalytic amount of a radical initiator, aphenol derivative and low-toxic and cheap bromide salt and water into a reaction vessel, reacting at room temperature at 5 W power in a photocatalytic reactor for a certain period, extracting with ethyl acetate and then re-crystallizing to obtain a polybrominated phenol compound. The above radical initiator is eosin, azobisisobutanol, sodium persulfate, ammonium persulfate or potassium persulfate.The free radical initiator and the bromine salt are cheap and easily available, and the method is an ideal synthesis method of the polybrominated phenol compound. According to the method, low-toxicity bromine salt instead of liquid bromine is used to carry out a bromination reaction, unstable and explosive hydrogen peroxide is replaced with the cheap and easily-available free radical initiator, and an emerging photocatalytic method is used. The polybrominated phenol compound can be obtained in a high yield by only using a 5W power lamp for the reaction, the reaction selectivity is high, by-products are less, and the post-treatment is simple.
Halogen-lithium exchange between substituted dihalobenzenes and butyllithium: Application to the regioselective synthesis of functionalized bromobenzaldehydes
Da?browski, Marek,Kubicka, Joanna,Luliński, Sergiusz,Serwatowski, Janusz
, p. 6590 - 6595 (2007/10/03)
Halogen-lithium interconversion reactions between unsymmetrically substituted mono- and bifunctional dihalobenzenes C6H 3XHal2 and C6H2XYHal2 (Hal=Br, I; X, Y=F, OR, CF3, CH(OMe)2) and butyllithium were investigated. The resultant organolithium intermediates were converted into the corresponding benzaldehydes in moderate to good yields. As a rule, bromine atoms in the position ortho to the functional group were replaced preferentially with lithium. Intramolecular competition experiments with bifunctional systems revealed that fluorine is capable of activating the neighboring bromine atom more strongly than methoxy and dimethoxymethyl groups. On the replacement of the non-activated bromine with iodine a complete reversal of this reactivity pattern can be accomplished due to the preferred iodine-lithium exchange.
