| abstract |
The present invention relates to a novel compound having an antagonistic activity of the p2x3 and / or p2x2 / 3 receptor. A compound of formula (I): Chemical Formula 1 (see Formula) wherein Ra and Rb, and Rd and Re are taken together to form oxo or the like; R4a and R4b are hydrogen or the like; n is 1 or the like; R2 is aryl or the like; s and s' is 0 or the like; R9 and R9 'are halogen or the like; R20a and R20b are hydrogen, alkyl or the like; u is 1 to 4; R13 is hydrogen or the like, or its pharmaceutically acceptable salt. |