Azobenzene is a typical class of synthesized photoswitch molecular. It can perform structural transformation through light excitation. The application of azobenzene, which can only be converted through visible light alone, has led to an increase in amounts in recent years in biomaterial areas. However, develop such a novel photoswitch is still a challenge. Whatâs more, the oxidation of the nitroso group, which is a starting material of Mills reaction, still needs to be overcome since it would decrease the reaction reactivity. Here we show different methods used for the synthesis of azobenzene. The Mills reaction method is the best choice for asymmetric azobenzene, which can be applied to peptides. This dissertation explores the approaches used to design an azobenzene derivative switched by visible light only. This work provides an idea of modifying a symmetric azobenzene derivative into an asymmetric azobenzene derivative that can be used in peptides. A corresponding synthetic route is also developed here. Azobenzene derivative [3-(3-aminomethylphenylazo)phenyl]acetic acid (AMPP), which can be used in peptides, has been synthesised and characterised in this project. Furthermore, an attempt to synthesis a novel o-fluoroazobenzene derivative that can only be converted through visible light and can be used in peptides was also be performed.