Process Development for the Sulfonamide Herbicide Pyroxsulam

Abstract

The development of a manufacturing process for the initial commercial production of pyroxsulam sulfonamide herbicide is described. The process encompasses seven reaction steps, and includes a new route to 4-(trifluoromethyl)pyridines, a scaleable method of lithiating a pyridine intermediate, and a sulfiliminecatalyzed formation of a sulfonamide.

Seed Pre-Treatment and Planting Geometry Positively Influence Herbicide Efficacy in Wheat (Triticum aestivum)

“…Pyroxsulam containing triazolopyrimidine provides broad spectrum post emergence annual grass and broadleaf weed control in cereals by inhibiting the action of ALS enzyme. Pyroxsulam's attributes of its superior toxicity and environmental-friendly profiles was made available commercially in 2008 (Gonzalea et al, 2008). Herbicide carryover phytotoxicity can be minimized with reduced rates of herbicide doses (Blackshaw et al, 2006).…”

Importance of a Fluorine Substituent for the Preparation of meta‐ and para‐Pentafluoro‐λ6‐sulfanyl‐Substituted Pyridines

“…Encouraged by this result, we further attempted the reaction with fluorinated pyridine disulfides 1f-h.A s expected, the corresponding SF 4 Cl products 2f-h were produced in good yields (74-77 %; Table 1, entries [6][7][8]. Fluorine substitution was also effective for the reaction of para-substituted pyridine disulfides.D isulfides of 2,6difluoropyridine,2 -fluoropyridine,a nd 3,5-difluoropyridine were very nicely converted into the corresponding p-SF 4 Clpyridine products 2i-k in 68-95 %y ield (Table 1, entries [9][10][11].…”

“…[1g, 2] Fluoropyridines [3] and trifluoromethylpyridines [4] are massively sought after building blocks for the preparation of pharmaceuticals and agrochemicals.I np articular, CF 3 -substituted pyridines occur widely in marketed drugs;t he HIV protease inhibitor tipranavir (Aptivus) [5] is ar epresentative example (see . Most widespread in biologically active compounds of this type is meta-CF 3 substitution of the pyridine ring (see Figure SI-1 [5,6] ), followed by ortho-and para-CF 3 substitution. [7] Owing to the success of trifluoromethylpyridines on the market [5,6] and the inherent recent difficulty in developing new small drugs by the current strategies,w eb ecame interested in pentafluoro-l 6 -sulfanyl (SF 5 )-substituted pyridines as novel potential building blocks for pharmaceuticals.…”

“…Most widespread in biologically active compounds of this type is meta-CF 3 substitution of the pyridine ring (see Figure SI-1 [5,6] ), followed by ortho-and para-CF 3 substitution. [7] Owing to the success of trifluoromethylpyridines on the market [5,6] and the inherent recent difficulty in developing new small drugs by the current strategies,w eb ecame interested in pentafluoro-l 6 -sulfanyl (SF 5 )-substituted pyridines as novel potential building blocks for pharmaceuticals. [8] TheS F 5 group has garnered substantial attention in recent years for specialty materials,pharmaceuticals,and agrochemicals.…”

Synthesis, characterization and catalytic activity of Cu(II), Co(II), Ni(II), Mn(II) and Fe(III) complexes of 4-((3-formyl-4-hydroxyphenyl)diazenyl)-N-(4-methyloxazol-2-yl) benzenesulfonamide

“…Sulfonamide has been also reported to possess good herbicidal [13] and corrosion inhibitory properties [14,15]. At the same time, N-salicylideneamino acidato metal complexes with different organic ligands have been prepared, characterized [16][17][18] then the chemical nuclease property of these metal complexes that intercalates into the DNA grooves [19] have been introduced.…”