PYRAZOLINE COMPOUNDS

The invention relates to pyrazoline compounds of formula wherein R1 is hydrogen or methyl, R2 and R3 are each independently of the other methyl, ethyl or hydroxyethyl, R4 is hydrogen or chlorine, R5 and R6 are each independently of the other hydrogen or methyl, R7 is hydrogen, methyl or phenyl, n is 0 or 1, with the proviso that, if n is 0 and R4 to R7 are hydrogen, R2 is methyl and R3 is hydroxyethyl, and X(-) is a C1-C3alkanoate, C1-C4alkanephosphonate, C1-C4alkanesulfonate, phosphite, sulfamate or glycolate anion and, if R1 is methyl, X(-) is also a methosulfate, chloride or bromide ion, to the preparation of said compounds, to the use thereof as fluorescent whitening agents, and to novel hydrazine intermediates of formula wherein R2 and R3 are methyl, ethyl or hydroxyethyl, and the acetone hydrazones and salts thereof.