| abstract |
The application provides a green synthesis method for an antiviral drug intermediate, comprising: in the presence of a catalyst, adding zinc powder and dihaloalkane to the compound shown in formula II to carry out a cyclization reaction to generate the compound shown in formula I ; The cyclization reaction does not need to add zinc halide; wherein, R 1 is selected from H or amino protecting group, R 2 is selected from heptyl, nonyl, decyl, fluoromethyl, trifluoromethyl, cyclopropylmethyl, C 1 - C6 alkyl, phenyl, p-fluorophenyl, benzyl, p-nitrobenzyl, 2-phenethyl or naphthylmethyl; R 3 and R 4 are each independently selected from hydrogen or C 1- C 6 alkyl, R 3 and R 4 can be connected to form an aliphatic ring containing 3-10 carbon atoms. The synthesis method has short steps, does not use dangerous and expensive materials, has high reaction conversion rate, short reaction time, and is easy to operate; it reduces production costs and post-processing costs, and has obvious cost advantages; it can be widely used for the preparation of antiviral drugs Matvir, boceprevir or nalaprevir have good market prospects. Formula II Formula I |