Di-quaternary salts of pyrimidylamino-quinolines having trypanodical properties are obtained by treating a pyrimidylamino-quinoline in which either the pyrimidine or the quinoline compound is in the form of a quaternary salt, and may be as described below, with a quaternary salt forming agent, such as methyl iodide, dimethyl sulphate and methyl p-toluene sulphonate. In the examples the pyrimidine nucleus is substituted in the 2-, 4- (or 6-) position by lower alkylamino, e.g. methyl-, and isopropylamino, or amino-groups, in another of these positions by a lower alkyl radical, e.g. methyl, or amino, or a lower alkylamino group, and is attached to the linking -NH- group at the remaining 2-, 4-(or 6-) positions, while the quinoline nucleus is substituted in the 4-position by an amino- or lower alkylamino-group, e.g. methylamino-, ethylamino-, and further by a lower alkyl group or groups, e.g. 2-methyl, and bears the linking -NH- group in the 6-position. If the 4-substituent in the quinoline nucleus is not lower alkylamino-, the pyrimidine nucleus must contain a lower alkylamino-group. The di-quaternary salts described include methiodides, and metho - p - toluene sulphonates, mostly being converted ultimately into the former, from other intermediate quaternary salts, such as the methyl sulphate. Pyrimidylaminoquinolines and their monoquaternary salts used as initial materials, substituted as described, may be obtained by condensing a suitably substituted 6-amino-quinoline or its quaternary salt with a 4-chloro-pyrimidine or its quaternary salt dehydrating the monohydrate obtained if necessary, and replacing the quaternary group if required, e.g. the hydriodides to the methiodides. 4-Methyl and ethyl-amino-6-aminoquinolines are obtained by hydrolysis of the N-acetyl derivatives. Specification 658,203 is referred to.