PREPARATION OF 1,1'-DIMETHYL-4,4'-BIPYRIDYLIUM DICHLORIDE

PURPOSE:To prepare the titled compound useful as a non-selective herbicide, in high yield, by reacting 4, 4'-bipyridyl with mono-chloroacetic acid in the presence of water using a suspending agent compriing a phosphoric acid salt and if necessary an aminopolycarboxylic acid. CONSTITUTION:The objective compound can be prepared without producing precipitate, by reacting 4, 4'-bipyridyl with monochloroacetic acid in the presence of water using a suspending agent comprising an alkali metal salt of phosphoric acid or its mixture with an aminopolycarboxylic acid and/or its salt, at 90- 130 deg.C for 1-7hr. The obtained compound can be compound as it is with various adjuvants for herbicide. The phosphoric acid salt is primary - tertiary phosphate, pyrophosphate, polyphosphate and its K salt, Na salt, etc., and the aminopolycarboxylic acid is e.g. nitrilotriacetic acid, ethylenediaminetetraacetic acid, and its Na, K, ammonium salt, etc.