Sunlight assisted synthesis of α-aminonitrile using Capillary flow microreactor: A new approach

The significance of continuous flow capillary reactor in reaction efficiency was investigated using a series of microreactors. We designed and fabricated 3 capillary microreactors starting with 3.0m, 7.5 m and 11.0m, capillary and the difference in efficiency and reduced reaction time was observed. These microreactors were used for the photochemical synthesis of α-aminonitriles. A cheap and readily available cyanide source (KCN) and a photoredox organic catalyst (Rose Bengal) were demonstrated to be vital requisites for this reaction. This reaction was carried out under sunlight irradiation, and excellent yields were recorded. Interestingly, we were able to affirm the effect of capillary reactor length on reaction time as a function of increased resident time of reaction mixture under the sun. The yield was still maintained around 80.6% on average for the three reactors, with the 11.0 m reactor showing the least reaction time of about 24 h. For the first time, we combined an organic dye and acetic acid (cocatalyst) for the synthesis of α-aminonitriles.