Trifluoro-p-tolunitrile: Synthesis & Application in Agrochemicals

Trifluoro-p-tolunitrile, C(8)H(4)F(3)N, at 123K contains molecules linked together through one C-H...F bond and two C-H...N hydrogen bonds into sheets that are further crosslinked to form a dense two-dimensional network without pi...pi ring interactions. The aromatic ring is slightly deformed due to the two para-related electronegative groups. This substance is a colourless, transparent liquid at ambient temperature with a pungent odour. Trifluoro-p-tolunitrile is poorly soluble in water but can be dissolved in organic solvents such as ethanol, diethyl ether, and toluene. The synthesis route of this kind of substance primarily employs p-chlorotrifluorotoluene and potassium cyanide as raw materials, yielding the compound via substitution reactions. The above process requires strict control of temperature and catalyst dosage to enhance yield. Besides, as a critical intermediate, it finds extensive application in pharmaceuticals, pesticides, and functional materials. Trifluoro-p-tolunitrile serves in synthesising fluorinated antibacterial drugs and highly effective herbicides, while also enabling the production of high-performance products such as fluorinated polyimides and organic optoelectronic materials.

Synthetic method of Trifluoro-p-tolunitrile compound

The isoxaflutole (isoxaflutole) is an inhibitor of hydroxy phenyl pyruvate dioxygenase, belongs to benzoyl isoxazole herbicides, and has the action principle that the biosynthesis of plastoquinone and tocopherol is hindered by inhibiting the synthesis of the p-hydroxy phenyl pyruvate dioxygenase to cause the accumulation of tyrosine, thereby influencing the biosynthesis of carotenoid. The invention relates to a method for preparing a Trifluoro-p-tolunitrile compound, wherein the structural formula of the Trifluoro-p-tolunitrile compound is shown as a formula (I), wherein X is a group selected from nitro or halogen; the compound shown in formula (II) is reacted with cuprous cyanide under the action of sodium bromide or/and potassium bromide to prepare the compound; the invention adopts the catalyst with low price, and the conversion rate and the selectivity of the reaction reach more than 95 percent; and inorganic salt and tar are easy to separate in the subsequent treatment process, so that the post-treatment process is simplified, the discharge of three wastes is reduced, and the method is suitable for industrial large-scale production.[1]

In view of various problems of the method for synthesizing the Trifluoro-p-tolunitrile compound in the prior art, the invention mainly aims to provide a method for synthesizing the p-trifluoromethyl benzonitrile compound with high yield and low production cost. In order to achieve the purpose, the invention adopts the technical scheme that: a method for synthesizing a Trifluoro-p-tolunitrile compound. The method comprises the following steps: (1) reacting a compound shown as a formula (II) with cuprous cyanide in the presence of a reaction solvent under the catalysis of a catalyst to obtain a reaction solution; wherein X is a group selected from nitro or halogen; the catalyst is selected from one or two of sodium bromide and potassium bromide; (2) distilling the reactant obtained in the step (1) to remove the solvent to obtain a crude product; (3) washing the crude product with a benzene solvent, and filtering to obtain a filtrate and a filter cake; distilling and separating benzene from the filtrate to obtain the Trifluoro-p-tolunitrile compound; and taking the filter cake to recover inorganic salt. The invention is further defined by: the recovered inorganic salt is used for reuse, and the reuse amount is 1 to 90 weight percent of the recovered inorganic salt, and preferably 30 to 60 weight percent.

Improved method of fluvoxamine synthesis

Here we use Trifluoro-p-tolunitrile as the starting material, 5-methoxy-4'-trifluoromethylphenylpentanone was synthesised via a Grignard reaction followed by hydrolysis. This was then oxamylated to yield 5-methoxy-4'-trifluoromethyl-O-(2-aminoethyl)pentanone oxime. Finally, the salt is formed with maleic acid to yield fluvoxamine. In this experiment, the product was purified using the coal dissolution and recrystallisation method, thereby avoiding the complex column chromatography separation required by other approaches and eliminating the need for reduction with LiAH. Through a series of improvements, the overall yield of the product reached 36.16%. Consequently, the method employed in this experiment offers advantages including readily available raw materials, straightforward operational control, and ease of industrialisation. Furthermore, Trifluoro-p-tolunitrile serves as a low-cost raw material.[2]

References

[1] CN109970602B

[2] Liu, Tao et al. Zhejiang da xue xue bao. Yi xue ban = Journal of Zhejiang University. Medical sciences vol. 32,5 (2003): 441-2. doi:10.3785/j.issn.1008-9292.2003.05.017

You may like