Search

EP-3784659-B1 - PROCESS FOR THE PREPARATION OF 1-(2-METHOXYMETHYL-3-METHYLPHENYL)4H-TETRAZOLIN-5-ONE

EP3784659B1EP 3784659 B1EP3784659 B1EP 3784659B1EP-3784659-B1

Inventors

  • HALLER, JAN

Dates

Publication Date
20260506
Application Date
20190415

Claims (11)

  1. A process for the preparation of 1-(2-methoxymethyl-3-methylphenyl)4H-tetrazolin-5-one, comprising a step of reacting 2-methoxymethyl-3-methyl phenyl isocyanate with an azide salt in a solvent and in the presence of a silicon derivative as a catalyst, wherein the silicon derivative is a trialkylsilyl azide, wherein the silicon derivative is prepared by reacting a trialkylsilyl halide compound with an azide salt, and wherein the silicon derivative is employed in a molar amount of less than 1.0 equivalent, relative to the isocyanate compound.
  2. The process according to claim 1, wherein the azide salt is sodium azide.
  3. The process according to claim 1 or 2, wherein the solvent is an amide, preferably selected from dimethylformamide, dimethylacetamide, N-methylpyrrolidone and combinations thereof.
  4. The process according to any one of claims 1 to 3, wherein the silicon derivative is trimethylsilyl azide.
  5. The process according to any one of claims 1 to 4, wherein the silyl halide compound is a silyl chloride compound.
  6. The process according to claim 5, wherein the silyl halide compound is trimethylsilyl chloride.
  7. The process according to any one of claims 1-6, wherein the silicon derivative is employed in a molar amount of less than 0.5 equivalent and more preferably less than 0.1 equivalent, relative to the isocyanate compound.
  8. The process according to any one of claims 1-7, wherein the step of reacting the isocyanate compound with the azide salt is performed at a temperature of at least 60°C, preferably of at least 80°C, and more preferably of at least 100°C.
  9. The process according to any one of claims 1-8, wherein a tetrazolinone salt is obtained after the step of reacting the isocyanate compound with the azide salt; and the process further comprises an additional step of treating the tetrazolinone salt with an acid to obtain the tetrazolinone compound.
  10. The process according to claim 9, comprising an intermediate purification step between the step of reacting the isocyanate compound with the azide salt and the additional step of treating the tetrazolinone salt with the acid.
  11. The process according to claim 9 or 10 further comprising a step of treating the tetrazolinone salt with sodium nitrite, before the additional step of treating the tetrazolinone salt with the acid, and preferably after the intermediate purification step.

Description

TECHNICAL FIELD The present invention relates to a process for the production of 1-(2-methoxymethyl-3-methylphenyl)4H-tetrazolin-5-one. TECHNICAL BACKGROUND Agricultural crops, damaged or destroyed by pests, represent an important issue worldwide. In fact, the costs of such damage exceed billions annually due to decreased crop yields, reduced crop quality and increased harvesting costs. Therefore, a strong demand exists for the control of pests in agricultural crops by safe and effective means, which would have no harmful effects to mammals and other living organisms. It has been disclosed in documents US 4956469, US 5003075 and US 5019152 that tetrazolinone derivatives exhibit pesticidal properties and can be useful as plant growth regulators. Furthermore, it has been found that tetrazolinone derivatives exhibit interesting properties which can be useful in the fields of medicinal chemistry or electronics. For instance, document US 5705653 mentions that tetrazolinone derivatives can be used as β3 agonists for the treatment of obesity and diabetes, while document US 2017/0200619 discloses the use of tetrazolinone derivatives for the removal of anti-reflective material and/or post-etch residue from micro electronic devices. Documents EP2990404, US 4839349, US 5530135, WO 2005/112941, WO 2013/162072 and US 2014/364414 disclose the preparation of tetrazolinone derivatives by reacting an isocyanate compound with sodium azide in the presence of aluminum chloride in tetrahydrofuran (THF) or dimethylformamide (DMF). However, aluminum chloride is a very hygroscopic solid that reacts violently with water. Its addition to DMF, which is one of the preferred reaction solvents, provokes heat generation. The hydrochloric acid generated after the reaction of aluminum chloride with water can then react with sodium azide to generate the explosive hydrazoic acid. Furthermore, the aluminum salts resulting from the aqueous work-up tend to cause problems during filtration. Documents US 5066667, US 5347010, WO 2004/80984, US 2011/130415, "Reactions of trimethylsilyl azide with heterocumulenes" (Journal of Organic Chemistry, 1980, 45, 5130), "Optically active antifungal azoles. VI. Synthesis and antifungal activity of N-[(1R,2R)-2-(2,4-Difluorophenyl)-2-hydroxy-1-methyl-3-(1H-1,2,4-triazol-1-yl)propyl]-N'-(4-substituted phenyl)-3(2H,4H)-1,2,4-triazolones and 5(1H,4H)-tetrazolones" (Chemical and Pharmaceutical Bulletin, 1996, 44, 314) and "Electronic properties of 1-methyl-4-phenyl-1H-tetrazole-5(4H)-thiones: An experimental and theoretical study" (Journal of Molecular Structure, 2009, 933, 38) disclose the preparation of tetrazolinone derivatives by reacting an isocyanate compound with a stoichiometric amount of trimethylsilyl azide either in benzene or without a solvent. Nevertheless, trimethylsilyl azide is a volatile compound, easily hydrolysable and highly toxic, which must be handled with great care in order to avoid inhalation and intoxication. In addition, trimethylsilyl azide is an expensive reagent and only 40% of its molar mass is actually found in the final product, the rest of the compound creating waste. There is thus a need for novel methods for the production of 1-(2-methoxymethyl-3-methylphenyl)4H-tetrazolin-5-one, that overcome the abovementioned issues and offer a safe and efficient route to such compounds. SUMMARY OF THE INVENTION It is a first object of the invention to provide a process for the preparation of 1-(2-methoxymethyl-3-methylphenyl)4H-tetrazolin-5-one (other name: 4-(2-methoxymethyl-3-methylphenyl)1H-tetrazolin-5-one with CAS number 1472649-96-9, herein also referred to as "the tetrazolinone"), comprising a step of reacting 2-methoxymethyl-3-methylphenylisocyanate (herein also referred as "the isocyanate compound") with an azide salt in a solvent and in the presence of a silicon derivative as a catalyst, wherein the silicon derivative is a trialkylsilyl azide, wherein the silicon derivative is prepared by reacting a trialkylsilyl halide compound with an azide salt, and wherein the silicon derivative is employed in a molar amount of less than 1.0 equivalent, relative to the isocyanate compound. According to some embodiments, the azide salt is sodium azide. According to some embodiments, the solvent is an amide, preferably selected from dimethylformamide, dimethylacetamide, N-methylpyrrolidone and combinations thereof. The silicon derivative is a trialkylsilyl azide, preferably trimethylsilyl azide. The silicon derivative is prepared by reacting a silyl halide compound with an azide salt. According to some embodiments, the silyl halide compound is a trialkylsilyl halide. According to some embodiments, the silyl halide compound is a silyl chloride compound. According to some embodiments, the silyl halide compound is trimethylsilyl chloride. The silicon derivative is employed in a molar amount of less than 1.0 molar equivalent, preferably less than 0.5 molar equivalent and more preferably less than 0.1