The present invention provides a compound represented by the formula: wherein R1 is a C1-4alkyl R2 is (1) a 5- to 7-membered nitrogen-containing heterocyclic group which may have a substituent selected from the group consisting of (1) a halogen, (2) a hydroxy group, (3) a C1-4alkyl and (4) a C1-4alkoxy, (2) a phenyl which may have a substituent selected from the group consisting of (1) a halogen, (2) a C1-4alkoxy-C1-4alkyl, (3) a mono-C1-4alkyl-carbamoyl-C1-4alkyl, (4) a C1-4alkoxy and (5) a mono-C1-4alkylcarbamoyl-C1-4alkoxy, or the like R3 is a C1-4alkyl R4 is a C1-4alkoxy, or the like n is an integer of 1 to 4 or a salt thereof, as a thienopyrimidine compound having gonadotropin-releasing hormone antagonistic activity.
