AGENT FOR THE REGULATION OF PLANT GROWTH

摘要

1393993 Pyrimidines CIBA-GEIGY AG 16 May 1972 [17 May 1971] 22973/72 Heading C2C Novel 5-nitropyrimidines of Formula I wherein R 1 represents C 2-6 alkyl, C 3-5 alkenyl, C 3-5 alkinyl, C 1-4 hydroxyalkyl, C 2-5 cyanoalkyl, or alkoxyalkyl or alkylamino alkyl or trialkylammonioalkyl wherein each alkyl moiety has 1-6 C atoms, or C 3-6 cycloalkyl optionally substituted by Me or Et; R 2 and R 3 which may be identical or different each represent H or C 1-6 alkyl; R 4 represents H, C 1-6 alkyl or C 3-6 cycloalkyl optionally substituted by Me or Et; R 5 represents C 1-6 alkyl; or R 1 and R 2 taken together form a C 2-6 polymethylene group, or R 3 and R 4 taken together form a C 4-6 polymethylene group, each of which may have a methylene group replaced by O or NR1 where R1 represents H or C 1-6 alkyl; and acid addition salts thereof with an inorganic or organic strong acid or quaternary salts thereof, may be prepared by exchanging the halogen atoms of a dihalopyrimidine of Formula IV successively with amines of formulµ HNR 1 R 2 and HNR 3 R 4 at a temperature between -60‹ C. and +120‹ C. in the presence of a base. Certain of the intermediate pyrimidines which may be isolated after the first step of the process, i.e. those containing a single halogen atom, are stated to be novel and these and the other novel compounds I of the invention exhibit plant growth regulant properties. An alternative preparative route for the compounds I is from the 2,4,6-trihalo-5-nitropyrimidine by reaction with HNR 1 R 2 and HNR 3 R 4 to give an intermediate (some of which are stated to be novel) which may be reacted with HSR 5 or an alkali metal salt thereof.