A compound of formula I wherein: R 1 and R 2 are each independently selected from the group consisting of -H, -CO 2 Et, -C NH 2, -C NHCH 3, -C N(CH 3) 2, -C 1-3 alkyl and -CH 2 OH; or R 1 and R 2, together with the carbon they are bonded to, may form a spiro ring selected from the group consisting of C 3-4 cycloalkyl, tetrahydrofuran and tetrahydropyran; R 3 and R 4 are both -H, or if R 1 and R 2 are both -H, R 3 and R 4 are independently selected from the group consisting of -H and -CH 3; R 5 is selected from the group consisting of phenyl, optionally substituted with one to two groups selected from the group consisting of -CN, -C 1-3 alkyl, optionally substituted with -OH, -C 3-6 cycloalkyl, -Cl, -F, -OC 1-3 alkyl, -C N(Me)(-CH 2 CH 2 OH), -C NH(-CH 2 CH 2 SO 2 CH 3), -C C 1-3 alkyl, -N(Me) 2, -NHC C 1-3 alkyl, -C OC 1-3 alkyl, -SO 2 C 1-3 alkyl, -CF 3, 3-hydroxy-pyrrolidine-1-carbonyl and [1,2,4]triazolyl; aryl or carbocycle selected from the group consisting of C 3-6 cycloalkyl, bicyclo[2.2.1]heptyl, decahydronaphthalenyl, indanyl, spiro[3.3]hept-1-yl, 6,7,8,9-tetrahydro-5H-benzocycloheptenyl and 1,2,3,4-tetrahydronaphthalenyl, wherein said aryl or carbocycle is optionally substituted with -CN, -Br, -OC 1-3 alkyl or phenyl; heterocyclyl selected from the group consisting of benzo[1,3]dioxolyl, 3H-benzoxazolyl, chromanyl, 3,4-dihydro-2H-benzo[b][1,4]dioxepinyl, 2,3-dihydrobenzo[1,4]dioxinyl, 2,3-dihydrobenzofuranyl, 4H-benzo[1,4]oxazinyl, 2,3-dihydro-1H-indolyl, 1,3-dihydroisobenzofuranyl, 1,4-dihydro-2H-isoquinolinyl, 3,4-dihydro-1H-[1,8]napthyridinyl, 3,4-dihydro-2H-pyrido[3,2-b][1,4]oxazinyl, 3,4-dihydroquinolinyl, 2-oxa-spiro[3,3]heptyl, piperidinyl, tetrahydrofuranyl, tetrahydropyranyl, 5,6,7,8-tetrahydroquinazolinyl, 1,2,3,4-tetrahydro-quinolinyl, wherein said heterocyclyl is optionally substituted with one to two groups selected from the group consisting of -C CH 3, -C 1-3 alkyl, -oxo and -C NH 2; and heteroaryl selected from the group consisting of 1H-indazolyl, pyridyl, and [1,2,3]-thiadiazolyl, wherein said heteroaryl is optionally substituted with one to two groups selected from the group consisting of -C 1-3 alkyl, -Cl and -CN; and n is 0 or 1; or a salt thereof. R 1 and R 2 are each independently selected from the group consisting of -H, -CO 2 Et, -C NH 2, -C NHCH 3, -C N(CH 3) 2, -C 1-3 alkyl and -CH 2 OH; or R 1 and R 2, together with the carbon they are bonded to, may form a spiro ring selected from the group consisting of C 3-4 cycloalkyl, tetrahydrofuran and tetrahydropyran; R 3 and R 4 are both -H, or if R 1 and R 2 are both -H, R 3 and R 4 are independently selected from the group consisting of -H and -CH 3; R 5 is selected from the group consisting of phenyl, optionally substituted with one to two groups selected from the group consisting of -CN, -C 1-3 alkyl, optionally substituted with -OH, -C 3-6 cycloalkyl, -Cl, -F, -OC 1-3 alkyl, -C N(Me)(-CH 2 CH 2 OH), -C NH(-CH 2 CH 2 SO 2 CH 3), -C C 1-3 alkyl, -N(Me) 2, -NHC C 1-3 alkyl, -C OC 1-3 alkyl, -SO 2 C 1-3 alkyl, -CF 3, 3-hydroxy-pyrrolidine-1-carbonyl and [1,2,4]triazolyl; aryl or carbocycle selected from the group consisting of C 3-6 cycloalkyl, bicyclo[2.2.1]heptyl, decahydronaphthalenyl, indanyl, spiro[3.3]hept-1-yl, 6,7,8,9-tetrahydro-5H-benzocycloheptenyl and 1,2,3,4-tetrahydronaphthalenyl, wherein said aryl or carbocycle is optionally substituted with -CN, -Br, -OC 1-3 alkyl or phenyl; heterocyclyl selected from the group consisting of benzo[1,3]dioxolyl, 3H-benzoxazolyl, chromanyl, 3,4-dihydro-2H-benzo[b][1,4]dioxepinyl, 2,3-dihydrobenzo[1,4]dioxinyl, 2,3-dihydrobenzofuranyl, 4H-benzo[1,4]oxazinyl, 2,3-dihydro-1H-indolyl, 1,3-dihydroisobenzofuranyl, 1,4-dihydro-2H-isoquinolinyl, 3,4-dihydro-1H-[1,8]napthyridinyl, 3,4-dihydro-2H-pyrido[3,2-b][1,4]oxazinyl, 3,4-dihydroquinolinyl, 2-oxa-spiro[3,3]heptyl, piperidinyl, tetrahydrofuranyl, tetrahydropyranyl, 5,6,7,8-tetrahydroquinazolinyl, 1,2,3,4-tetrahydro-quinolinyl, wherein said heterocyclyl is optionally substituted with one to two groups selected from the group consisting of -C CH 3, -C 1-3 alkyl, -oxo and -C NH 2; and heteroaryl selected from the group consisting of 1H-indazolyl, pyridyl, and [1,2,3]-thiadiazolyl, wherein said heteroaryl is optionally substituted with one to two groups selected from the group consisting of -C 1-3 alkyl, -Cl and -CN; and n is 0 or 1; or a salt thereof.