A compound of formula I wherein R 1 is hydrogen, C 1-6 alkyl, or haloC 1-6 alkyl; R 2 is C 1-6 alkyl, C 2-6 alkenyl, C 1-6 alkoxy, hydrogen, hydroxy, haloC 1-6 alkyl, phenylC 1-6 alkoxy, amino, C 1-6 alkylamino or diC 1-6 alkylamino; R 3 is phenyl; phenyl substituted by one, two or three substituents independently selected from C 1-6 alkyl, C 3-7 cycloalkyl, halogen, haloC 1-6 alkyl, cyano, nitro, -C(=O)OR 4, -OR 5,-SO 2 R 6 and -C(=O)NR 7 R 8; thiophenyl; thiophenyl substituted by one, two or three substituents independently selected from C 1-6 alkyl, C 1-6 alkyoxy and halogen; furanyl; furanyl substituted by one, two or three substituents independently selected from C 1-6 alkyl, C 1-6 alkyoxy and halogen; N -containing heteroaryl; or N -containing heteroaryl substituted with one, two or three substituents independently selected from C 1-6 alkyl, C 1-6 alkyoxy, halogen, haloC 1-6 alkyl, cyano, nitro, -C(=O)OR 4, -OR 5 and -SO 2 R 6; wherein, R 4 is hydrogen or C 1-6 alkyl; R 5 is hydrogen, C 1-6 alkyl, haloC 1-6 alkyl, hydroxyC 1-6 alkyl, C 1-6 alkoxyC 1-6 alkyl or phenylC 1-6 alkyl; R 6 is C 1-6 alkyl, haloC 1-6 alkyl, amino, C 1-6 alkylamino or diC 1-6 alkylamino; R 7 and R 8 are independently selected from hydrogen, C 1-6 alkyl, haloC 1-6 alkyl, hydroxyC 1-6 alkyl and C 1-6 alkoxyC 1-6 alkyl; Q is hydrogen, C 1-6 alkyl, C 1-6 alkoxy, halogen, or haloC 1-6 alkyl; U, W and Z are independently selected from C and N; one of X and Y is N, and the other one is C or N; or pharmaceutically acceptable salts, or enantiomers for use in the treatment or prophylaxis of HBV infection. R 1 is hydrogen, C 1-6 alkyl, or haloC 1-6 alkyl; R 2 is C 1-6 alkyl, C 2-6 alkenyl, C 1-6 alkoxy, hydrogen, hydroxy, haloC 1-6 alkyl, phenylC 1-6 alkoxy, amino, C 1-6 alkylamino or diC 1-6 alkylamino; R 3 is phenyl; phenyl substituted by one, two or three substituents independently selected from C 1-6 alkyl, C 3-7 cycloalkyl, halogen, haloC 1-6 alkyl, cyano, nitro, -C(=O)OR 4, -OR 5,-SO 2 R 6 and -C(=O)NR 7 R 8; thiophenyl; thiophenyl substituted by one, two or three substituents independently selected from C 1-6 alkyl, C 1-6 alkyoxy and halogen; furanyl; furanyl substituted by one, two or three substituents independently selected from C 1-6 alkyl, C 1-6 alkyoxy and halogen; N -containing heteroaryl; or N -containing heteroaryl substituted with one, two or three substituents independently selected from C 1-6 alkyl, C 1-6 alkyoxy, halogen, haloC 1-6 alkyl, cyano, nitro, -C(=O)OR 4, -OR 5 and -SO 2 R 6; wherein, R 4 is hydrogen or C 1-6 alkyl; R 5 is hydrogen, C 1-6 alkyl, haloC 1-6 alkyl, hydroxyC 1-6 alkyl, C 1-6 alkoxyC 1-6 alkyl or phenylC 1-6 alkyl; R 6 is C 1-6 alkyl, haloC 1-6 alkyl, amino, C 1-6 alkylamino or diC 1-6 alkylamino; R 7 and R 8 are independently selected from hydrogen, C 1-6 alkyl, haloC 1-6 alkyl, R 4 is hydrogen or C 1-6 alkyl; R 5 is hydrogen, C 1-6 alkyl, haloC 1-6 alkyl, hydroxyC 1-6 alkyl, C 1-6 alkoxyC 1-6 alkyl or phenylC 1-6 alkyl; R 6 is C 1-6 alkyl, haloC 1-6 alkyl, amino, C 1-6 alkylamino or diC 1-6 alkylamino; R 7 and R 8 are independently selected from hydrogen, C 1-6 alkyl, haloC 1-6 alkyl, hydroxyC 1-6 alkyl and C 1-6 alkoxyC 1-6 alkyl; Q is hydrogen, C 1-6 alkyl, C 1-6 alkoxy, halogen, or haloC 1-6 alkyl; U, W and Z are independently selected from C and N; one of X and Y is N, and the other one is C or N;