Method of making vitamin K1

This invention discloses a method of making vitamin K1. The mentioned method of making vitamin K1 comprises performing a first one-pot synthesis with base catalyst, performing a first hydrolysis, performing a substitution, and performing a second one-pot synthesis without metal oxidant. The starting material of this invention is stable 2-methyl-1,4-naphthoquinone. Preferably, this invention provides a method of making vitamin K1 efficiently on simplifying the operation and decreasing the side-product. More preferably, without metal residue, the vitamin K1 of this invention is without metal residue and more safety for clinical application.