A compound of formula I, wherein X 1 C-R 1 or N; X 2 C-R 1 or N; X 3 C-R 1 or N; X 4 C-R 1 or N; whereby only one of X 1, X 2, X 3 and X 4 is N or all of X 1, X 2, X 3 and X 4 are C-R 1; Y is O or S m; m is 0, 1 or 2; R 1 each separately is selected from the group consisting of hydrogen, halogen, hydroxy, C 1-6 -alkyl- and C 1-6 -alkoxy-; R 2 is selected from the group consisting of H and C 1-6 -alkyl-; R 3 is selected from the group consisting of H and C 1-6 -alkyl-; or R 2 and R 3 together are =O; R 4 is selected from the group consisting of i) aryl-C 1-6 -alkyl-, wherein the aryl moiety can be optionally substituted by halogen, ii) C 1-6 -alkoxy-CH 2 -, iii) C 1-6 -alkyl-, iv) C 2-6 -alkenyl-CH 2 -, v) C 2-6 -alkynyl-CH 2 -, vi) halogen-C 1-6 -alkyl-, vii) halogen-C 2-6 -alkenyl-CH 2 -, and viii) hydrogen; R 5 is selected from the group consisting of i) aryl-, ii) aryl-C 1-6 -alkyl-, wherein the aryl moiety can be optionally substituted by C 1-6 -alkyl, halogen-C 1-6 -alkyl or halogen, and the C 1-6 -alkyl moiety can optionally be substituted by C 1-6 -alkyl-COO-, halogen or hydroxy, iii) C 3-10 -cycloalkyl-C 1-6 -alkyl-, iv) halogen-C 1-6 -alkyl-, v) heteroaryl-C 1-6 -alkyl-, wherein the heteroaryl moiety can be optionally substituted by halogen, vi) heterocycloalkyl-C 1-6 -alkyl-, vii) C 1-6 -alkyl-, viii) C 2-6 -alkenyl-CH 2 - that is optionally substituted by halogen, (C 1-6 -alkyl) 3 SiO-, C 1-6 -alkyl-COO- or C 1-6 -alkyl-OOC-, ix) C 1-6 -alkoxy-CH 2 -, and x) C 2-6 -alkynyl-CH 2 -; or R 4 and R 5 together are selected from the group consisting of i) C 3-10 -cycloalkyl that is optionally substituted by C 1-6 -alkyl, C 1-6 -alkoxy, C 1-6 -alkyl-OOC-, C 1-6 -alkyl-COO-, halogen, halogen-C 1-6 -alkyl, hydroxy-C 1-6 -alkyl or oxo; ii) heterocycloalkyl that is optionally substituted by benzyl, C 1-6 -alkyl, C 1-6 -alkyl-OOC-, halogen-C 1-6 -alkyl or oxo; iii) C 3-10 -cycloalkenyl that is optionally substituted by C 1-6 -alkyl, C 1-6 -alkyl-OOC-, halogen-C 1-6 -alkyl, (C 1-6 -alkyl) 3 SiO-C 1-6 -alkyl- or hydroxy-C 1-6 -alkyl, and iv) indanyl when Y is SO 2; or pharmaceutically acceptable salts thereof. X 1 C-R 1 or N; X 2 C-R 1 or N; X 3 C-R 1 or N; X 4 C-R 1 or N; whereby only one of X 1, X 2, X 3 and X 4 is N or all of X 1, X 2, X 3 and X 4 are C-R 1; Y is O or S m; m is 0, 1 or 2; R 1 each separately is selected from the group consisting of hydrogen, halogen, hydroxy, C 1-6 -alkyl- and C 1-6 -alkoxy-; R 2 is selected from the group consisting of H and C 1-6 -alkyl-; R 3 is selected from the group consisting of H and C 1-6 -alkyl-; or R 2 and R 3 together are =O; R 4 is selected from the group consisting of i) aryl-C 1-6 -alkyl-, wherein the aryl moiety can be optionally substituted by halogen, ii) C 1-6 -alkoxy-CH 2 -, iii) C 1-6 -alkyl-, iv) C 2-6 -alkenyl-CH 2 -, v) C 2-6 -alkynyl-CH 2 -, vi) halogen-C 1-6 -alkyl-, vii) halogen-C 2-6 -alkenyl-CH 2 -, and viii) hydrogen; i) aryl-C 1-6 -alkyl-, wherein the aryl moiety can be optionally substituted by halogen, ii) C 1-6 -alkoxy-CH 2 -, iii) C 1-6 -alkyl-, iv) C 2-6 -alkenyl-CH 2 -, v) C 2-6 -alkynyl-CH 2 -, vi) halogen-C 1-6 -alkyl-, vii) halogen-C 2-6 -alkenyl-CH 2 -, and viii) hydrogen; R 5 is selected from the group consisting of i) aryl-, ii) aryl-C 1-6 -alkyl-, wherein the aryl moiety can be optionally substituted by C 1-6 -alkyl, halogen-C 1-6 -alkyl or halogen, and the C 1-6 -alkyl moiety can optionally be substituted by C 1-6 -alkyl-COO-, halogen or hydroxy, iii) C 3-10 -cycloalkyl-C 1-6 -alkyl-, iv) halogen-C 1-6 -alkyl-, v) heteroaryl-C 1-6 -alkyl-, wherein the heteroaryl moiety can be optionally substituted by halogen, vi) heterocycloalkyl-C 1-6 -alkyl-, vii) C 1-6 -alkyl-, viii) C 2-6 -alkenyl-CH 2 - that is optionally substituted by halogen, (C 1-6 -alkyl) 3 SiO-, C 1-6 -alkyl-COO- or C 1-6 -alkyl-OOC-, ix) C 1-6 -alkoxy-CH 2 -, and x) C 2-6 -alkynyl-CH 2 -; i) aryl-, ii) aryl-C 1-6 -alkyl-, wherein the aryl moiety can be optionally substituted by C 1-6 -alkyl, halogen-C 1-6 -alkyl or halogen, and the C 1-6 -alkyl moiety can optionally be substituted by C 1-6 -alkyl-COO-, halogen or hydroxy, iii) C 3-10 -cycloalkyl-C 1-6 -alkyl-, iv) halogen-C 1-6 -alkyl-, v) heteroaryl-C 1-6 -alkyl-, wherein the heteroaryl moiety can be optionally substituted by halogen, vi) heterocycloalkyl-C 1-6 -alkyl-, vii) C 1-6 -alkyl-, viii) C 2-6 -alkenyl-CH 2 - that is optionally substituted by halogen, (C 1-6 -alkyl) 3 SiO-, C 1-6 -alkyl-COO- or C 1-6 -alkyl-OOC-, ix) C 1-6 -alkoxy-CH 2 -, and x) C 2-6 -alkynyl-CH 2 -; or R 4 and R 5 together are selected from the group consisting of i) C 3-10 -cycloalkyl that is optionally substituted by C 1-6 -alkyl, C 1-6 -alkoxy, C 1-6 -alkyl-OOC-, C 1-6 -alkyl-COO-, halogen, halogen-C 1-6 -alkyl, hydroxy-C 1-6 -alkyl or oxo; ii) heterocycloalkyl that is optionally substituted by benzyl, C 1-6 -alkyl, C 1-6 -alkyl-OOC-, halogen-C 1-6 -alkyl or oxo; iii) C 3-10 -cycloalkenyl that is optionally substituted by C 1-6 -alkyl, C 1-6 -alkyl-OOC-, halogen-C 1-6 -alkyl, (C 1-6 -alkyl) 3 SiO-C 1-6 -alkyl- or hydroxy-C 1-6 -alkyl, and iv) indanyl when Y is SO 2; or pharmaceutically acceptable salts thereof. i) C 3-10 -cycloalkyl that is optionally substituted by C 1-6 -alkyl, C 1-6 -alkoxy, C 1-6 -alkyl-OOC-, C 1-6 -alkyl-COO-, halogen, halogen-C 1-6 -alkyl, hydroxy-C 1-6 -alkyl or oxo; ii) heterocycloalkyl that is optionally substituted by benzyl, C 1-6 -alkyl, C 1-6 -alkyl-OOC-, halogen-C 1-6 -alkyl or oxo; iii) C 3-10 -cycloalkenyl that is optionally substituted by C 1-6 -alkyl, C 1-6 -alkyl-OOC-, halogen-C 1-6 -alkyl, (C 1-6 -alkyl) 3 SiO-C 1-6 -alkyl- or hydroxy-C 1-6 -alkyl, and iv) indanyl when Y is SO 2;