Two-step tandem synthesis of sugar-containing pyrimidine derivatives catalyzed by Lipozyme® TL IM in continuous-flow microreactors

A novel series of sugar-containing pyrimidine derivatives have been synthesized via an effective and convenient two-step tandem synthesis in continuous-flow microreactors with excellent regioselectivity. Using continuous-flow microreactors to assemble two-step reactions into one unit can effectively avoid separating and purifying intermediates. Moreover, this method allows the optimization of reaction parameters for each unit individually. The salient features of this method include a reduction in the use of DMSO and mild reaction conditions (30-40 °C). Under the optimum reaction conditions, we can obtain the desired yield (34.8-69.1%) in a shorter time (40 min) than the shaking condition (48 h). In continuous-flow microreactors, a two-step tandem scheme was developed to synthesize a series of sugar-containing pyrimidine derivatives with excellent regioselectivity, which can effectively avoid the separation and purification of intermediates.