20 parts by weight of 2-(2,6-dichlorophenoxy)ethyl bromide dissolved in 75
parts by volume of ethanol are slowly added with stirring to 37 parts by
weight of hydrazine hydrate in 25 parts by volume of ethanol. The mixture is
boiled under reflux conditions for 16 h. The solvent and excess hydrazine are
removed by distillation under reduced pressure. Water and excess solid
sodium hydroxide are added to make the mixture alkaline. The mixture is
extracted with chloroform, dried over anhydrous potassium carbonate, filtered
and freed from solvent by distillation. The residual oil is distilled at 1 mm of
mercury pressure. The fraction boiling at 132° to 140°C and consists of 2-
(2,6-dichlorophenoxy)ethyl hydrazine.
23 parts by weight of 2-(2,6-dichlorophenoxy)ethyl hydrazine and 14.46 parts
by weight of S-methylisothiouronium sulfate in 150 parts by volume of water
are boiled together under reflux conditions for 4 h. The solid which
precipitates on cooling is recrystallized from water and consists of 14.5 parts
by weight of N-[2-(2,6-dichlorophenoxy)ethylamino]guanidine hydrogen
sulfate having a melting point of 214°C.
