On January 7, 1999, Kanno, Hisashi; Yoshida, Kazuo; Sato, Tsutomu; Sato, Kobi; Kanda, Yoichi published a patent.Category: pyridine-derivatives The title of the patent was Preparation of 6-phenoxypicolinic acid alkylidenehydrazide derivatives as herbicides. And the patent contained the following:
Claimed are 6-Phenoxypicolinic acid alkylidenehydrazide derivatives [I; R1 = halo, C1-4 alkyl, C1-4 haloalkyl, C1-4 alkoxy, C1-4 haloalkoxy, C1-4 alkylthio, C1-4 alkylamino, C1-4 dialkylamino, (C1-4 alkyl)(C7-8aralkyl)amino; m = 0-3; R2, R3 = H, C1-10 C2-6 alkenyl, C2-6 alkynyl, C3-6 cycloalkyl, Ph, or aryl-C1-3 alkyl each optionally substituted with Xa or Xb; ; X1, Xb = halo, C1-4 alkoxy, C1-4 alkylthio, C1-4 alkyl, C3-6 cycloalkyl, or cyano; na = nb = 0 or integer selected from number of H atoms substitutable with Xa and Xb in R2 and R3; or when R2 and R3 are an alkyl chain, R2 and R3 are directly linked together to form a ring optionally interposed with O, S, or optionally C1-4 alkyl-substituted NH; Y = C1-4 alkyl, C1-4 haloalkyl, C1-4 alkoxy, C1-4 haloalkoxy, C1-4 alkylthio, or halo; p = 0-5; when m, n, na, nb, and p are ≥2, R1, R2, Xa, Xb, and Y are same or different groups], a process for producing these, and a herbicide containing any of the derivatives as the active ingredient. These compounds exhibit excellent herbicidal activity with high selectivity at low dosage and does not inflict damage to the subsequent crops in double-cropping. Thus, 6-methoxy-6-[3-(trifluoromethyl)phenoxy]picolinic acid was stirred with chloroacetaldehyde in a mixture of 40% aqueous NaOH and EtOH at room temperature for ∼4 h to give 88% 6-methoxy-6-[3-(trifluoromethyl)phenoxy]picolinic acid (2-chloroethylidene)hydrazide (II). II 100 g/10 post emergence are controlled ≥50% Amaranthus retroflexus, Brassica kaber, Solanum nigrum, and Galium spurium. The experimental process involved the reaction of Methyl 6-bromo-5-methoxypicolinate(cas: 170235-18-4).Category: pyridine-derivatives
The Article related to phenoxypicolinic acid alkylidenehydrazide preparation herbicide, Heterocyclic Compounds (One Hetero Atom): Pyridines and other aspects.Category: pyridine-derivatives