Synthesis methods
Industrial parabromoaniline is as raw material, by diazotization, iodo-synthesis of bromo iodobenzene. Preferred synthesis conditions: firstly 0.02mol parabromoaniline is dissolved in a mass fraction of 20% sulfuric acid medium, then reacts with 0.021molNaNO2 to generate bromophenyl diazonium sulfate at-10℃, and then chloroform and 0.021molKI is added into solution to process iodination reaction, after simple treatment bromo-iodobenzene crude product (which the bromo-iodobenzene HPLC purity 98.4%) is obtained, total yield after purification is 80%, increases by 15% than before improved. The product processes structural characterization by IR and 1HNMR. The improved method can greatly improve the purity of the crude product, this avoids the trouble of going through the column, this method is safe and easy to operate, easy to control the process, cost is lower, it is more suitable for the preparation of 1-Bromo-4-iodobenzene.
Unit: Heilongjiang University of Chemistry and Materials Science
Author: Guo Jing Bai Xuefeng Lvhong Fei
Uses
1. 1-Bromo-4-iodobenzene is used for organic synthesis.
2. Used as substrate for copper-free Sonogashira coupling reaction in aqueous acetone.
3. For the synthesis of β,β-dibromostyrene.
Chemical Properties
white to brown cryst. powder, crystals or needles
Uses
1-Bromo-4-iodobenzene has been employed:
- as reagent for in situ desilylation and coupling of silylated alkynes
- as starting reagent in the total syntheses of ent-conduramine A and ent-7-deoxypancratistatin (alkaloids)
- as substrate in copper-free Sonogashira coupling in aqueous acetone
- in synthesis of β,β,dibromostyrenes
General Description
Vapour pressure as a function of temperature for 1-bromo-4-iodobenzene has been studied using a diaphragm manometer and torsion mass-loss effusion.
Synthesis
The p-bromoiodobenzene was synthesized by diazotization and iodination using industrial p-bromoaniline as raw material. The better synthesis conditions: firstly, 0.02 mol of p-bromoaniline was dissolved in 20% sulfuric acid, and reacted with 0.021 mol of NaNO2 to form p-bromobenzene diazonium sulfate at -10 , and then chloroform and 0.021 mol of KI were added to the solution for iodine substitution, and then p-bromoiodobenzene was obtained as a crude product after simple post-processing (in which the purity was 98.4%), and the total yield after purification was 80%, which was better than that of the improved synthesis. 98.4%), and the total yield reached 80% after purification, which was 15% higher than that before improvement. The product was structurally characterized by IR and 1HNMR. The improved method greatly improved the purity of the crude product, avoided the trouble of passing through the column, was easy and safe to operate, easy to control the process, low cost, and more suitable for the preparation of p-bromoiodobenzene.
UnitSchool of Chemistry, Chemical Engineering and Materials, Heilongjiang University
AuthorGuo Jing, Bai Xuefeng, Lv Hongfei
