Diamidine derivatives of formula (I) and their salts are new. Amidine derivatives of formula (I) and their salts are new. [Image] X : a group of formula (ii) or R 4; Z : -(CH 2) m-; m : 8 - 21; n : 0 or 1; Y : R 3 or a group of formula (iii); R 1 and R' 1H, alkyl, aryl, OH, O-alkyl, O-aryl, OCO-alkyl, OCO-aryl, O-CO-O-(or S or NH)-alkyl, O-CO-O-(or S or NH)-aryl, PO-(O-alkyl or O-aryl) 2, CO-O-CH 2-aryl, or cycloalkyl; R 2 and R' 2H, alkyl, CO-O-CH 2-aryl, CO-O-alkyl, or cycloalkyl; R 3 and R' 3H, alkyl, aryl, CO-O-alkyl, CO-O-aryl, COO-CH(R)-O-CO-alkyl, PO(O-alkyl, or O-aryl, or ONa) 2, or CO-O-CH(R)-aryl; R : H or alkyl; NR 1R 2, NR' 1R' 2, NR 2R 3, NR' 2R' 3a heterocycle, in which R 2 and R 3 and/or R' 2 and R' 3 may be doubly bonded to the nitrogen atom; R 4 and R' 4H or alkyl; R 1R 4, R' 1R' 4-(CH 2) p-; R 4R 2, R' 4R' 2-(CH 2) p; p : 3 - 5; and provided that: (1) when X is a group of formula (ii), then Y is R 3; and (2) when X is R 4, then Y is a group of formula (iii). [Image] Independent claims are also included for the preparation of compounds of formulae (V), (X), (VI) and (VIII). [Image] R anot defined. ACTIVITY : Protozoacide. 1,12-bis(imidazolin-2-yl) dodecane (Ib) was given orally and intraperitoneally to mice infected with Plasmodium vinckei. The dose that cleared 50 % of the infection (ED50) was 3.4 mg/kg i.p and 62 mg/kg p.o. MECHANISM OF ACTION : Not given in source material.本發明係關於具有抗寄生蟲活性之化合物,特別係抗瘧疾活性,其特徵在於其符合通式(I);(I);其中;-或者,X係代表式(II)之基團;(II);其中Z係基團-(CH2)m,其中m=8至21,n=0或1,;且Y=R3,;.R1及R'1係彼此相同或不同,選自H、烷基、芳基、OH、O-烷基、O-芳基、O-CO-烷基、O-CO-芳基、O-CO-O(或S或NH)-烷基、O-CO-O(或S或NH)-芳基、PO(O-烷基或O-芳基)2、CO-O-CH2-芳基、環烷基,.R2及R'2係彼此相同或不同,選自H、烷基、CO-O-CH2-芳基、CO-O-烷基、環烷基,.R3及R'3係彼此相同或不同,代表H、烷基、芳基、CO-O-烷基、CO-O-芳基、COO-CH(R)-O-CO-烷基、PO(O-烷基或O-芳;基或ONa)2、CO-O-CH(R)-芳基,.R係H或烷基,或者,.R1及R2及/或R'1及R'2或是R2及R3及/或R'2及R'3與其所分別連結之氮原子共同形成一雜環,又或者,.R2及R3及/或R'2及R'3可為相同之取代基,雙連結於該氮原子上,分別與R1及R'1環化以形成雜環,該雜環如需要可經Ra取代,該Ra係選自H、烷基、經1、2、或3個鹵原子取代之烷基、芳基、CO-O-烷基(或芳基)、-CO-OH、-CO-NH2、-CN、-CO-NH-烷基(或芳基)、-CO-N