Pesticidal intermediate 3-substd.-furo-(3,2-c)pyridine derivs. - prepd. e.g. by reacting 4-hydroxy-nicotinic acid ester(s) with haloacetic acid derivs.

摘要

Furo(3,2-C)pyridine derivs. of formula (Ia) and their 3-oxoltautomers of formula (Ib) and their salts with strong acids or bases are new. In (I), R1 is 1-3C alkyl, 1-3C alkoxy or phenyl; R2 is CH3; R3 is H, Cl or Br; R4 is H, 1-6C alkyl, 5-7C cycloalkyl, CN, -CO-R5, -COOR6, -CONR7R8, p-NO2,-C6H4-, or benzyl opt. substd. (pref. mono- or disubstd.) in the ring by 1-4C alkyl, halogen, 1-3C alkoxy, methylenedioxy and/or di(1-4C alkyl)amino; R5 is CH3, or phenyl opt. substd. by NO2 and/or Cl; R6 is 1-4C alkyl; R7 is H or 1-3C alkyl; and R8 is H 1-3C alkyl, or phenyl opt. substd. by halogen, CF3 and/or CH3; or R7+R8 is 4-5C methylene chain opt. interrupted by O, S, NH or N-(1-4C alkyl). (I) are useful as intermediates, e.g. for plant protection agents (esp. phosphorus esters obtd. by reacting alkali salts of (Ia, b) with phosphorus halides such as phosphoric acid diester halides).