A compound of formula, or a tautomer, racemate, enantiomer or diastereoisomer thereof, or a mixture thereof or a pharmaceutically acceptable salt thereof: wherein: R 1 and R 2 are each independently selected from the group consisting of hydrogen, alkyl, alkenyl, alkynyl, cycloalkyl and heterocyclic alkyl; R 3 is selected from the group consisting of hydrogen, alkyl, alkenyl, alkynyl, cycloalkyl and heterocyclic alkyl; R 4 and R 5 are each independently selected from the group consisting of hydrogen, alkyl, alkoxyl, hydroxyl, and halogen; R 6 is selected from the group consisting of alkyl, cycloalkyl and heterocyclic alkyl, wherein the alkyl or heterocyclic alkyl is each optionally substituted with one or more groups selected from the group consisting of alkyl, alkoxyl, hydroxyl, sulfuryl, carbonyl, cycloalkyl, cycloalkylalkyl, heterocyclic alkyl, -C R 9, -C NR 9 R 10, -NR 9 R 10; wherein the cycloalkyl is optionally substituted with one or more groups selected from the group consisting of alkyl, alkoxyl, hydroxyl, sulfuryl, carbonyl, cycloalkyl, cycloalkylalkyl, heterocyclic alkyl, -C R 9, -C NR 9 R 10, -NR 9 R 10, carboxy or carboxylic ester; R 7 and R 8 are each independently selected from the group consisting of hydrogen, alkyl and halogen; R 9 and R 10 are each independently selected from the group consisting of hydrogen, alkyl, cycloalkyl and heterocyclic alkyl,wherein the alkyl or cycloalkyl is each optionally substituted with one or more groups selected from the group consisting of alkyl, halogen, hydroxyl, cyano, alkoxyl, aryloxyl, cycloalkyl, cycloalkylalkyl, heterocyclic alkyl; or, R 9 and R 10 are taken together with the attached N atom to form a 4 to 8 membered heterocycle, wherein the 4 to 8 membered heterocycle contains one or more N, O or S n heteratoms, and the 4 to 8 membered heterocycle is each optionally substituted with one or more groups selected from the group consisting of alkyl, halogen, hydroxyl, haloalkyl, cyano, alkoxyl, aryloxyl, hydroxylalkyl, cycloalkyl, cycloalkylalkyl, heterocyclic alkyl; and n is 0, 1 or 2. R 1 and R 2 are each independently selected from the group consisting of hydrogen, alkyl, alkenyl, alkynyl, cycloalkyl and heterocyclic alkyl; R 3 is selected from the group consisting of hydrogen, alkyl, alkenyl, alkynyl, cycloalkyl and heterocyclic alkyl; R 4 and R 5 are each independently selected from the group consisting of hydrogen, alkyl, alkoxyl, hydroxyl, and halogen; R 6 is selected from the group consisting of alkyl, cycloalkyl and heterocyclic alkyl, wherein the alkyl or heterocyclic alkyl is each optionally substituted with one or more groups selected from the group consisting of alkyl, alkoxyl, hydroxyl, sulfuryl, carbonyl, cycloalkyl, cycloalkylalkyl, heterocyclic alkyl, -C R 9, -C NR 9 R 10, -NR 9 R 10; wherein the cycloalkyl is optionally substituted with one or more groups selected from the group consisting of alkyl, alkoxyl, hydroxyl, sulfuryl, carbonyl, cycloalkyl, cycloalkylalkyl, heterocyclic alkyl, -C R 9, -C NR 9 R 10, -NR 9 R 10, carboxy or carboxylic ester; R 7 and R 8 are each independently selected from the group consisting of hydrogen, alkyl and halogen; R 9 and R 10 are each independently selected from the group consisting of hydrogen, alkyl, cycloalkyl and heterocyclic alkyl,wherein the alkyl or cycloalkyl is each optionally substituted with one or more groups selected from the group consisting of alkyl, halogen, hydroxyl, cyano, alkoxyl, aryloxyl, cycloalkyl, cycloalkylalkyl, heterocyclic alkyl; or, R 9 and R 10 are taken together with the attached N atom to form a 4 to 8 membered heterocycle, wherein the 4 to 8 membered heterocycle contains one or more N, O or S n heteratoms, and the 4 to 8 membered heterocycle is each optionally substituted with one or more groups selected from the group consisting of alkyl, halogen, hydroxyl, haloalkyl, cyano, alkoxyl, aryloxyl, hydroxylalkyl, cycloalkyl, cycloalkylalkyl, heterocyclic alkyl; and n is 0, 1 or 2.