| abstract |
It is an object of the present invention to provide a method for producing a high-purity tricyclic heterocyclic compound represented by formula (I), which is useful as a production intermediate for a pharmaceutical agent, wherein the method is an efficient production method with short steps and with a high yield, which does not use, as raw materials, expensive bromopyruvate and highly harmful copper chromite, and does not need silica gel column chromatography that generates, as by-products, large quantities of waste. The present invention relates to production of Compound (I) by the following method. |