Patent ID: 7569570

Claim:
A compound represented by the formula wherein R 1 is C 1-4 alkyl, R 2 is (I) phenyl optionally having 1 to 3 substituents selected from (1)amino, (2) —NR 5 COR 6 (R 5 is a hydrogen atom, and R 6 is C 1-4 alkyl, or mono C 1-4 alkylamino), (3) —CONR 9 R 10 (R 9 is a hydrogen atom, C 1-4 alkyl or C 3-8 cycloalkyl, R 10 is a hydrogen atom or C 1-4 alkyl), (4) —CO 2 R 13 (R 13 is C 1-4 alkyl), (5)C 1-4 alkoxy optionally having a hydroxyl group, C 1-4 alkoxy, C 1-4 alkyl-carbonyloxy, —NR 7 SO 2 R 8 (R 7 is a hydrogen atom and R 8 is C 1-4 alkyl), —CONR 9 R 10 (R 9 is a hydrogen atom or C 1-4 alkyl and R 10 is a hydrogen atom or C 1-4 alkyl, or R 9 and R 10 form a ring together with the adjacent nitrogen atom) or —CO 2 R 13 (R 13 is C 1-4 alkyl), (6) C 1-4 alkyl optionally having a hydroxyl group, —CONR 9 R 10 (R 9 is a hydrogen atom or C 1-4 alkyl and R 10 is C 1-4 alkyl) or C 1-4 alkoxy, (7) a halogen atom, (8) a hydroxyl group and (9) nitro (II) a heterocyclic group optionally having 1 to 3 substituents selected from C 1-4 alkoxy, C 1-4 alkyl, a halogen atom, a hydroxyl group and oxo, (III) C 3-8 cycloalkyl optionally having a hydroxyl group, or (IV) C 1-4 alkyl optionally having 1 to 3 substituents selected from (1) a 5 to 7-membered nitrogen-containing heterocyclic group, (2) a hydroxyl group and (3) C 1-4 alkoxy, R 3 is a hydrogen atom or C 1-4 alkyl, and R 4 is (I) C 1-4 alkyl having 1 to 3 substituents selected from (1)—CONR 18 R 19 (R 18 is a hydrogen atom or C 1-4 alkyl, R 19 is C 1-4 alkyl optionally having C 1-4 alkoxy, or R 18 and R 19 may form a ring together with the adjacent nitrogen atom), (2) a 5 to 7-membered nitrogen-containing heterocyclic group optionally having (1′) hydroxy-C 1-4 alkyl, (2′) C 1-4 alkoxy-carbonyl or (3′) mono C 1-4 alkyl-carbamoyl, (3) C 1-4 alkoxy-carbonyl, (4) carboxyl and (5) N—C 1-4 alkyl-N—C 7-10 aralkylamino or (II) C 3-8 cycloalkyl, or a salt thereof.