| abstract |
The present invention provides an efficient and superior process for preparing a benzofuran or pyridofuran derivative represented by the formula [I]: wherein X is a group of the general formula: -N= or -CH=; R1 is a hydrogen atom, a halogen atom, a lower alkyl group, a lower alkoxy group, a cyano group or an amino group optionally substituted with a lower alkyl group; Ring A is a nitrogen-containing heterocyclic group; Ring B is an optionally substituted benzene ring or an optionally substituted pyridine ring; and R3 is a hydrogen atom or a lower alkyl group, or a pharmaceutically acceptable salt thereof, which is useful as an activated blood coagulation factor X inhibitor. |