The present invention relates to a compound of formula I: wherein: R1 is a hydrogen atom, F, CN, etc.; R2 is CO, SO2, etc.; R3 is a phenyl which may be substituted; X1, X2, and X3 each independently CH, N, etc. provided, however, that among X1, X2 and X3, the number of nitrogen is 0 or 1; W is the following residue: wherein: W1, W2, and W3 each independently CH, N, etc., or a pharmaceutically acceptable salt or ester thereof.