The present invention relates to a compound of general formula I:wherein:n1 and n2 are the same or different, and are 0 or 1 R is aryl, heteroaryl, etc. Re is hydrogen atom or lower alkyl two groups selected from four groups consisting of (i) either one of Ra1 and Ra1, (ii) either one of Ra2 and Ra2, (iii) either one of Rb1 and Rb1, and (iv) either one of Rb2 and Rb2, are combined to form -(CH2)n- where n is 1, 2 or 3 and among Ra1, Ra1, Ra2, Ra2, Rb1, Rb1, Rb2 and Rb2, the groups which do not form -(CH2)n- are each independently hydrogen atom, etc. X1, X2, X3 and X4 are each independently CH, N, etc. Y1, Y2, Y3 and Y4 are the same or different and are CH or N, etc. W is a 5-membered aromatic heterocyclic group,or a pharmaceutically acceptable salt or ester thereof.
