Patent GB-949132-A (GB)
Title: Pyridazone derivatives and herbicidal agents containing the same
Inventor: REICHENEDER FRANZ
IPC: A01N43/58
Filed: 1962-03-21
Abstract: Agents for influencing plant growth, e.g. for dehydration, acceleration of ripening by premature desiccation, reducing fruit setting, retarding blossoming, prolonging the harvest period and storage life and for promoting the growth of shoots and roots, contain a compound of formula <FORM:0949132/C1/1> where X is halogen, R1 is alkyl, phenyl or cyclo-alkyl and may be substituted, R2 is hydrogen, R3 is amino or substituted amino or-CONHR7, where R7 is phenyl, halophenyl, or a substituted or unsubstituted pyridazonylureido alkylene radical (both pyridazonyl groups then being identical), or R2 and R3 are together =N­N or =C(R4)NR5R6, where R4 is hydrogen or alkyl and R5 and R6 are substituted or unsubstituted alkyl, or R4 and R5, or R5 and R6, together with the nitrogen atom, make up a heterocyclic ring (see Division C2).  Salts of these compounds are also referred to.  These compounds may be used as emulsions, suspensions or solutions in water or organic liquids. Other substances having plant growth influencing properties, or fertilizers, may be added.ALSO:The invention comprises compounds of formula: <FORM:0949132/C2/1> where X is halogen, R1 is alkyl, phenyl or cycloalkyl and may be substituted, R2 is hydrogen, R3 is amino or substituted amino or -CONHR7, where R7 is phenyl, halophenyl, or a substituted or unsubstituted pyridazonylureidoalkylene radical (both pyridazonyl groups then being identical), or R2 and R3 are together =N­N or =C(R4)NR5R6, where R4 is hydrogen or alkyl and R5 and R6 are substituted or unsubstituted alkyl, or R4 and R5, or R5 and R6 together with the nitrogen atom, make up a heterocyclic ring. Suitable substituents for R1 are chloro, methyl and nitro. Suitable substituted amino R3 radicals are the corresponding radicals in hydrazines and hydrazones.  Suitable R7 radicals are methyl, b -chloroethyl and 3,4-dichlorophenyl. Salts of these compounds are referred to. The compounds may be obtained by methods analogous to known methods.  The following compounds are prepared or referred to, X being C1 in each case and R1 and -NR2R3 as given: phenyl, azido; phenyl, hydrazino (and hydrazones by reaction with ketones e.g. acetone and methyl ethyl ketone); phenyl, -N=CHN (CH3)2; phenyl, N-methyl -2- pyrrolidinimino; cyclohexyl, hydrazino; methyl, hydrazino; phenyl N-pyrrolidinomethylimino; phenyl, 1-(N-pyrrolidino) - ethylimino; phenyl, 1-(N-morpholino) - ethylimino; phenyl, 1-(N-piperidino)-propylimino; phenyl, -NHCONHC6H5; phenyl, -NHCONHC6H4Cl(-m); and the compound  <FORM:0949132/C2/2> 1-Phenyl -4- amino -5- chloropyridazone (6) is obtained from ammonia and the 4,5-dichlorocompound.  The compounds of the invention are of use for influencing plant growth (see Division A5).ALSO:Agents for influencing plant growth contain a compound of formula <FORM:0949132/A5-A6/1> where X is halogen, R1 is alkyl, phenyl or cycloalkyl and may be substituted, e.g. chloro, methyl or nitro, R2 is hydrogen, R3 is amino or substituted amino or -CONHR7, where R7 is phenyl, halophenyl, or a substituted or unsubstituted pyridazonylureidoalkylene radical (both pyridazonyl groups then being identical), or R4 and R3 are together =N\sN or =C(R4) NR5R6, where R4 is hydrogen or alkyl and R5 and R6 are substituted or unsubstituted alkyl, or R5 and R5, or R5 and R6, together with the nitrogen atom, make up a heterocyclic ring (see Division C2).  Salts of these compounds are also referred to, e.g. the hydrohalides, sulphuric, phosphoric, formic or acetic acid salts.  These compounds may be used as emulsions, suspensions or solutions in water or organic liquids such as high boiling mineral oils or chlorohydrocarbons.  Other substances having bactericidal, fungicidal, or plant growth influencing properties, or fertilizers, may be added.