Crystalline form B of an anthranilamide insecticide and conversion of form B into form A Description The present invention relates to a crystalline form B of the anthranilamide insecticide 2-(3- chloro-2-pyridyl)-N-[2-methyl-4-chloro-6-[(diethyl-A ⁴ -sulfanylidene)carbamoyl]phenyl]-5- (trifluoromethyl)pyrazole-3-carboxamide and to different processes for converting said crystalline form B into a crystalline form A. The compound 2-(3-chloro-2-pyridyl)-N-[2-methyl-4-chloro-6-[(diethyl-A ⁴ -sulfanylidene)carba- moyl]phenyl]-5-(trifluoromethyl)pyrazole-3-carboxamide belongs to the class of anthranilamide insecticides, for which cyantraniliprole and chlorantraniliprole are prominent examples. The compound is depicted below, and will be referred to as compound I in the following.

It has been found that, among the subclass of N-pyridylpyrazole carboxanilides carrying a sul- fiminocarbonyl group in the ortho position with respect to the amide group, 2-(3-chloro-2- pyridyl)-N-[2-methyl-4-chloro-6-[(diethyl-A ⁴ -sulfanylidene)carbamoyl]phenyl]-5-(trifluoro- methyl)pyrazole-3-carboxamide (i.e. compound I) is particularly advantageous in terms of its high activity against invertebrate pests. N-pyridylpyrazole carboxanilides carrying a sulfimino- carbonyl group in the ortho position with respect to the amide group have e.g. been described in WO 2007/006670.

Compound I is described in WO 2007/006670 and can be obtained as an amorphous substance. Compound I can also be obtained as an amorphous substance, when it is prepared according to the process described, e.g., in WO 2013/024008. However, WO 2013/024008 further discloses that the process described therein provides compound I in such a high purity that it may be crystallized from suitable solvents to obtain a crystalline form A of compound I, which, in an X-ray powder diffractogram at 25°C and Cu-K _Q radiation, shows at least four of the ten following reflexes, given as 2Θ values: 9.31 , 1 1 .22, 15.50, 15.79, 17.16, 18.38, 18.74, 18.98, 26.23, 26.58. As can be taken from the experimental section of WO 2013/024008, the crystalli- zation process preferably comprises dissolving the crude product in acetonitrile upon heating, cooling the solution and isolating the formed solid, and then concentrating the mother-liquor, cooling it and again isolating the formed solid.

It has been found that crystalline form A of compound I is advantageous in terms of its storabil- ity and transportability. Furthermore, it has been found that crystalline form A is advantageous for the use against invertebrate pests because, although it has a low solubility in water, it can effectively be applied as an aqueous suspension concentrate.

Nevertheless, knowing that different crystalline forms of a compound may differ from each other with respect to one or more physical properties, such as solubility and dissociation, true density, crystal shape, compaction behaviour, flow properties and/or solid state stability, there remains an interest to find further crystalline forms of compound I, which may be advantageous over crystalline form A in terms of some of the above listed properties, e.g. in terms of the solubility.

On the other hand, if storability and transportability of compound I come into focus, it may be required to be able to convert such crystalline forms into crystalline form A in an energy-saving and cost-efficient manner. Furthermore, it may be required to achieve conversion within short duration times.

In view of the above, it is an object of the present invention to provide a further crystalline form of compound I, which has improved solubility properties compared to crystalline form A.

Furthermore, it is an object of the present invention to provide a process for converting said crystalline form of compound I into crystalline form A in an energy-saving and cost-efficient manner.

It is yet another object of the present invention to provide a process for converting said crystalline form of compound I into crystalline form A within short duration times.

These objects are achieved by the subject matter of the claims.

In one aspect, the present invention relates to a crystalline form B of 2-(3-chloro-2-pyridyl)-N- [2-methyl-4-chloro-6-[(diethyl-A ⁴ -sulfanylidene)carbamoyl]phenyl]-5-(trifluoromethyl)py razole-3- carboxamide (i.e. compound I), which, in an X-ray powder diffractogram at 25°C and Cu-K _Q radiation, shows at least four of the ten following reflexes, given as 2Θ values: 7.01 , 8.26, 9.16, 10.99, 12.21 , 13.93, 16.46, 17.22, 18.28, 20.89.

It has surprisingly been found that the crystalline form B of compound I, which could be obtained by adding a boiling solution of compound I in acetonitrile to liquid nitrogen, has improved solubility properties in water compared to crystalline form A of compound I. In particular, solubility studies have shown that the solubility of crystalline form B in water is about twice as high as the solubility of crystalline form A in water. This may e.g. result in a higher bioavailability of crystalline form B compared to crystalline form A. Furthermore, it has been found that the crystalline form B is storage stable at room temperature because conversion into crystalline form A only occurs at about 124°C as can be taken from a DSC curve measured by a differential scanning calorimeter (DSC) at a scan rate of 25°C per minute. Thus, the crystalline form B also has a solid state stability, which is sufficient for commercial purposes. In another aspect, the present invention relates to a process for converting the crystalline form B as defined herein into a crystalline form A of 2-(3-chloro-2-pyridyl)-N-[2-methyl-4-chloro-6- [(diethyl-A ⁴ -sulfanylidene)carbamoyl]phenyl]-5-(trifluoromethyl)py razole-3-carboxamide (i.e. compound I), which, in an X-ray powder diffractogram at 25°C and Cu-K _Q radiation, shows at least four of the ten following reflexes, given as 2Θ values: 9.31 , 1 1 .22, 15.50, 15.79, 17.16, 18.38, 18.74, 18.98, 26.23, 26.58,

the process comprising the steps of

(a) forming a dispersion of the crystalline form B as defined herein in a solvent selected from aqueous solvents, organic solvents and mixtures thereof; and

(b) stirring or shaking the dispersion at a temperature of at least 0°C.

Said process will be referred to as "process 1 ". The process is particularly advantageous because energy-consuming and therefore costly techniques such as evaporation crystallization or crystallization from hot solutions can be avoided. As demonstrated by means of examples, complete conversion of crystalline form B into crystalline form A can be e.g. be achieved at room temperature within about 2 hours, if a dispersion of crystalline form B is stirred in ethyl acetate as solvent. Thus, complete conversion can also be achieved within short duration times. In yet another aspect, the present invention relates to a process for converting the crystalline form B as defined herein into a crystalline form A of 2-(3-chloro-2-pyridyl)-N-[2-methyl-4-chloro- 6-[(diethyl-A ⁴ -sulfanylidene)carbamoyl]phenyl]-5-(trifluoromethyl)py razole-3-carboxamide (compound I), which, in an X-ray powder diffractogram at 25°C and Cu-K _Q radiation, shows at least four of the ten following reflexes, given as 2Θ values: 9.31 , 1 1.22, 15.50, 15.79, 17.16, 18.38, 18.74, 18.98, 26.23, 26.58,

the process comprising the steps of

(a) forming a solution of the crystalline form B as defined herein in a solvent selected from aqueous solvents, organic solvents and mixtures thereof, optionally under heating; and

(b) causing crystallization by evaporating the solvent from the solution and/or cooling the so- lution.

Said process will be referred to as "process 2". In certain situations, said process may be advantageous because conversion of crystalline form B into crystalline form A can be achieved within very short duration times, if dissolution, solvent evaporation and/or cooling are performed quickly.

Further embodiments of the present invention can be found in the claims, the description and the examples. It is to be understood that the features mentioned above and those still to be illustrated below of the subject matter of the invention can be applied not only in the respective given combination but also in other combinations without leaving the scope of the invention.

In the context of the present invention, the terms, which are used, are each defined as follows: The ability of a substance to exist in more than one crystalline form is generally referred to as polymorphism and the different "crystalline forms" are also named "polymorphs" and may be characterized by certain analytical properties such as their X-ray powder diffraction (XRPD) patterns or their DSC curves measured by a differential scanning calorimeter. Preferably, the crystalline forms, which are described herein, are essentially free from solvent, which means that the crystalline forms comprise no detectable amounts of solvents incorporated into the crystal lattice, i.e. in the 3-dimensional crystal lattice, wherein the molecules are positioned. In particu- lar, the amount of solvent in the crystal lattice is less than 10 mol%, preferably less than 5 mol%, more preferably less than 1 mol% based on compound I.

X-ray powder diffraction (XRPD) data as provided herein can be obtained using a Panalytical X'pert Pro diffractometer (manufacturer: Panalytical) in reflection geometry in the range of 2Θ = 3°-35° with increments of 0.0167° using Cu-K _Q radiation (at 25°C). The intensity of the reflexes is typically plotted versus the 2Θ angle to obtain a diffractogram. Such a diffractogram typically shows at least 2, preferably at least 4, more preferably at least 6, still more preferably at least 7, particularly preferably at least 10 reflexes. The skilled person will understand that the 2Θ values, which can be determined from the diffractogram and which are provided herein, often represent approximate values within an error margin in the range of from 0.1 to 0.4, preferably from 0.1 to 0.2. Thus, a 2Θ value of, e.g., 7.01 may be understood as a 2Θ value of 7.01 ±0.2, preferably 7.01 ±0.1 , more preferably 7.01 ±0.05, particularly preferably exactly 7.01.

DSC curves as provided herein can be obtained using a differential scanning calorimeter (e.g. a Mettler Toledo DSC 823e module) at a scan rate of 25°C per minute, wherein the sample is heated in crimped aluminum pans. The heat flux is then plotted versus the heating rate. The exothermic and endothermic peaks, which can be measured, represent, e.g., crystallization or recrystallization processes (exothermic) or melting processes (endothermic). The peaks are typically defined by their onset temperature, i.e. the temperature, at which an exothermic or endothermic process begins, and their peak temperature, i.e. the temperature at the peak maxi- mum or minimum.

Mixtures of two crystalline forms may be identified by comparing the recorded 2Θ values and DSC curves with the respective data of both crystalline forms alone. If the diffractogram shows characteristic reflexes of both crystalline forms, it can be concluded that a mixture of the two crystalline forms is present.

If crystalline form B of compound I as defined herein is converted into crystalline form A by the process according to the present invention, conversion may be started from compound I being exclusively present in crystalline form B or from compound I being present in the form of a mixture of crystalline form B and A. On the other hand, if the conversion is incomplete, a mixture of crystalline form B and crystalline form A is obtained by the process according to the present invention. Furthermore, if the process according to the present invention is started from a mixture of crystalline form B and A and the conversion is incomplete, another mixture of the two crystalline forms is obtained, wherein crystalline form A is enriched. Such mixtures may be analyzed and identified as indicated above. Furthermore, by analyzing of whether a mixture of crystalline forms B and A is obtained or crystalline form A alone, it can be determined whether par- tial or complete conversion of crystalline form B into crystalline form A has occurred.

In this context, the term "complete conversion" means that at least 90 wt.-%, preferably at least 95 wt.-%, more preferably at least 98 wt.-%, most preferably at least 99 wt.-%, based on the total weight of crystalline form B with which the conversion process was started, is converted into crystalline form A. Particularly preferably, "complete conversion" means that crystalline form B is quantitatively converted into crystalline form A.

On the other hand, the term "partial conversion" refers to the situation, where crystalline form B is converted into crystalline form A at least to some extent, i.e. that at least 1 wt.-%, preferably at least 5 wt.-%, more preferably at least 10 wt.-%, most preferably at least 40 wt.-% is convert- ed, based on the total weight of crystalline form B with which the conversion process was started.

As used herein, the term "chemically pure" means that a substance, e.g. compound I or a crystalline form thereof or the amorphous form thereof or any mixture thereof, is provided in a purity of at least 95%, preferably at least 97%, more preferably at least 98%, most preferably at least 99%, wherein the percent values refer to the substance weight based on the total weight of the substance together with any impurities. The chemical purity of compound I may be determined by NMR, quantitative HPLC and the like.

As used herein, the term "aqueous solvent" includes aqueous solutions, such as aqueous salt solutions including, e.g., sodium chloride solutions, sodium carbonate solutions, sodium hydrogen carbonate solutions, potassium carbonate solutions and potassium hydrogen carbonate solutions; aqueous acid and base solutions, such as hydrochloric acid or sodium hydroxide solution; and water itself. Preferred aqueous solvents will be listed below.

As used herein, the term "organic solvent" includes any organic solvent including aprotic and protic solvents, unpolar and polar solvents, water-immiscible and water-miscible solvents, aromatic and non-aromatic solvents, and mixtures thereof. Preferred organic solvents according to the present invention will be listed below.

Mixtures of aqueous solvents and organic solvents may be biphasic solvent systems or mo- nophasic solvent systems depending on the miscibility of the solvents. Preferred solvent mix- tures according to the present invention will be listed below.

The remarks made below concerning preferred embodiments of the invention are valid on their own as well as preferably in combination with each other as well as concerning the processes and the crystalline forms according to the invention.

In a first aspect, the present invention relates to a novel crystalline form B of compound I, which is further described herein after.

In one embodiment, the present invention relates to a crystalline form B of compound I, which, in an X-ray powder diffractogram at 25°C and Cu-K _Q radiation, shows at least four of the ten following reflexes, given as 2Θ values: 7.01 , 8.26, 9.16, 10.99, 12.21 , 13.93, 16.46, 17.22, 18.28, 20.89.

In a preferred embodiment, the present invention relates to a crystalline form B of compound I, which, in an X-ray powder diffractogram at 25°C and Cu-K _Q radiation, shows at least six, prefer- ably at least eight, of the ten following reflexes, given as 2Θ values: 7.01 , 8.26, 9.16, 10.99,

12.21 , 13.93, 16.46, 17.22, 18.28, 20.89. In view of the above comments, a skilled person knows that the above 2Θ values may be understood as being within a certain error margin, i.e.

7.01 ±0.2, 8.26±0.2, 9.16±0.2, 10.99±0.2, 12.21 ±0.2, 13.93±0.2, 16.46±0.2, 17.22±0.2,

18.28±0.2, 20.89±0.2, preferably 7.01 ±0.1 , 8.26±0.1 , 9.16±0.1 , 10.99±0.1 , 12.21 ±0.1 ,

13.93±0.1 , 16.46±0.1 , 17.22±0.1 , 18.28±0.1 , 20.89±0.1 , more preferably 7.01 ±0.05, 8.26±0.05, 9.16±0.05, 10.99±0.05, 12.21 ±0.05, 13.93±0.05, 16.46±0.05, 17.22±0.05, 18.28±0.05,

20.89±0.05, and particularly preferably 7.01 , 8.26, 9.16, 10.99, 12.21 , 13.93, 16.46, 17.22, 18.28, 20.89. In a preferred embodiment, the crystalline form B shows in an X-ray powder diffractogram at 25°C and Cu-K _Q radiation, at least six, frequently at least seven or eight, particularly preferably nine of the ten following reflexes, given as 2Θ values: 7.01 , 8.26, 9.16, 10.99, 12.21 , 13.93, 16.46, 17.22, 18.28, 20.89.

In another preferred embodiment, the crystalline form B shows in an X-ray powder

diffractogram at 25°C and Cu-K _Q radiation at least the following four reflexes, given as 2Θ values: 7.01 , 8.26, 12.21 , 13.93. In another preferred embodiment, the crystalline form B shows in an X-ray powder diffractogram at 25°C and Cu-K _Q radiation at least the following six reflexes, given as 2Θ values: 7.01 , 8.26, 9.16, 10.99, 12.21 , 13.93. Particularly preferably, the crystalline form B shows the following ten reflexes, given as 2Θ values: 7.01 , 8.26, 9.16, 10.99, 12.21 , 13.93, 16.46, 17.22, 18.28, 20.89.

In a particularly preferred embodiment, the present invention relates to a crystalline form B of 2-(3-chloro-2-pyridyl)-N-[2-methyl-4-chloro-6-[(diethyl-A ⁴ -sulfanylidene)carbamoyl]phenyl]-5- (trifluoromethyl)pyrazole-3-carboxamide, which, in an X-ray powder diffractogram at 25°C and Cu-Κα radiation, shows at least the following ten reflexes, given as 2Θ values: 7.01 , 8.26, 9.16, 10.99, 12.21 , 13.93, 16.46, 17.22, 18.28, 20.89.

The relative intensities of the reflexes can vary depending on the sample preparation technique, the sample mounting procedure, the particular instrument employed, and the morphology of the sample. Nevertheless, it can be preferred that the crystalline form shows the following seven reflexes, given as 2Θ values, with the highest intensity: 7.01 , 10.99, 12.21 , 13.93, 17.22, 18.28 and 20.89.

In another preferred embodiment of the invention, the crystalline form B is characterized by an X-ray diffraction pattern which is similar to that of Figure 1 . Preferably, the crystalline form B is characterized by an X-ray diffraction pattern, which corresponds to that of Figure 1 , in terms of the 2Θ values of the measured reflexes.

As already indicated above, the crystalline form B is, in a preferred embodiment of the invention, a non-solvated crystalline form.

In a preferred embodiment of the invention, the crystalline form B exhibits, in a DSC curve measured by a differential scanning calorimeter at a scan rate of 25°C per minute, an exother- mic peak with an onset temperature in the range of 74 to 80°C. Said exothermic peak may alternatively be identified by a peak temperature in the range of 121 to 127°. In a particularly preferred embodiment, the crystalline form B exhibits, in a DSC curve measured by a differential scanning calorimeter at a scan rate of 25°C per minute, an exothermic peak, which is characterized by an onset temperature in the range of 74 to 80°C and a peak temperature in the range of 121 to 127°C. Without being bound to theory, it appears that said exothermic peak indicates the recrystallization of crystalline form B into crystalline form A. Accordingly, said exothermic peak is characteristic for crystalline form B and is not present in a DSC curve measured with a sample of crystalline form A. It is preferred that the onset temperature of said exothermic peak is in the range of 76 to 78°C, and that the peak temperature is in the range of 123 to 125°C.

In a more preferred embodiment of the invention, the crystalline form B further exhibits, in the DSC curve, an endothermic peak with an onset temperature in the range of 137 to 143°C, e.g. in the range of 139 to 141 °C. Alternatively, said endothermic peak may be identified by a peak temperature in the range of 177 to 183°C. In a particularly preferred embodiment, the crystalline form B exhibits, in a DSC curve measured by a differential scanning calorimeter at a scan rate of 25°C per minute, an endothermic peak with an onset temperature in the range of 137 to 143°C and a peak temperature in the range of 177 to 183°C. Said endothermic peak may be interpreted as a melting peak, with the maximum in the range of 177 to 183°C, preferably in the range of 179 to 181 °C, being the melting point. Without being bound to theory, it is assumed that the endothermic peak represents the melting process of crystalline form A, which is formed at lower temperatures as indicated above in the context of the exothermic peak. However, in view of the fact that the melting temperature according to the maximum of the melting peak of the DSC curve is lower than the melting temperature, which can be determined from the DSC curve, if a sample of pure crystalline form A is measured (about 190°C), it is assumed that the melting process interrupts the recrystallization process of crystalline form B into crystalline form A, so that the peak temperature reflects the melting temperature of a mixture of crystalline forms A and B, or the melting temperature of crystalline form A containing crystalline form B as an impurity.

It is noted that the DSC curve preferably also comprises one further exothermic peak with an onset temperature in the range of 187 to 191 °C. Said exothermic peak is a decomposition peak, which can also be observed in the DSC curve of a sample of pure crystalline form B.

As already mentioned above, crystalline form B of compound I may be obtained by adding a boiling solution of compound I in acetonitrile to liquid nitrogen. Preferably, a boiling solution of 45 to 55 g of compound I in 180 to 220 ml. is added in a dropwise fashion to a dewar bowl con- taining liquid nitrogen, and the resulting solids are collected and dried.

It has been found that crystalline form B exhibits a surprisingly high solubility in water. In a preferred embodiment of the invention, crystalline form B is soluble in water in a concentration of at least 1.2 g/L, preferably at least 1 .5 g/L, more preferably at least 1 .8 g/L. In another preferred embodiment, crystalline form B is soluble in water in a concentration in a range of from 1 .8 to 2.0 g/L, e.g. in a concentration of about 2.0 g/L. In comparison, crystalline form A is soluble in water in a concentration of about 1 g/L. The higher solubility of crystalline form B can provide advantages, when the compound I is used against invertebrate pests, e.g. when contacting invertebrate pests or their food supply, habitat, breeding grounds or their locus with a pesticidally effective amount of the compound I.

Accordingly, the present invention also relates in one embodiment to the use of crystalline form B of compound I as a pesticide for controlling invertebrate pests. In another embodiment, the present invention relates to the use of crystalline form B of compound I for combating insects, acarids or nematodes. Furthermore, the present invention relates in one embodiment to a method of contacting the invertebrate pests, in particular insects, acarids or nematodes, or their food supply, habitat, breeding grounds or their locus with a pesticidally effective amount of crystalline form B of compound I.

In certain situations, it can be advantageous to provide mixtures of crystalline form B and crystalline form A and/or the amorphous form of compound I. For example, a mixture of crystalline form B and crystalline form A can be advantageous, when it is desired to combine the advanta- geous properties of crystalline form B in terms of the solubility with the advantageous properties of the storability and transportability of crystalline form A. Preferred weight ratios of crystalline form B to crystalline form A in such mixtures may e.g. be in the range of from 60:40 to 40:60 or from 10:90 to 40:60 or from 90:10 to 60:40. It is preferred that the amorphous form is only pre- sent in such mixtures in minor amounts, e.g. in an amount of less than 10 wt.-% or less than 5 wt.-% based on the total weight of the mixture, or not contained in the mixtures at all.

In another embodiment, the present invention relates to the use of a mixture of crystalline form B and crystalline form A and/or the amorphous form of compound I as a pesticide for controlling invertebrate pests, in particular insects, acarids or nematodes. In yet another embodiment, the present invention relates to a method of contacting the invertebrate pests, in particular insects, acarids or nematodes, or their food supply, habitat, breeding grounds or their locus with a pesti- cidally effective amount of a mixture of crystalline form B, crystalline form A and/or the amorphous form of compound I.

The crystalline form B and mixtures thereof with crystalline form A and/or the amorphous form of compound I are particularly suitable for efficiently controlling arthropodal pests such as arachnids, myriapedes and insects as well as nematodes. Specific pests are listed, e.g., in WO 2007/006670, WO 2013/024008 or WO 2014/053407 in the context of N-pyridylpyrazole carboxanilides carrying a sulfiminocarbonyl group in the ortho position with respect to the amide group including compound I. In principal, crystalline form B of compound I should be suitable for efficiently controlling the same pests as disclosed for the amorphous form and crystalline form A of compound I. However, due to the higher solubility of crystalline form B and the higher bioavailability resulting thereof, crystalline form B should provide for certain advantages when being used for controlling invertebrate pests.

The crystalline form B or a mixture thereof with crystalline form A and/or the amorphous form of compound I as defined above can be converted into customary formulations, for example solutions, emulsions, suspensions, dusts, powders, pastes and granules. The use depends on the particular intended purpose; in each case, it should ensure a fine and even distribution of the mixtures according to the invention.

Therefore the invention also relates to agrochemical compositions comprising at least one auxiliary and crystalline form B or a mixture thereof with crystalline form A and/or the amorphous form of compound I as defined above.

An agrochemical composition comprises a pesticidally effective amount of crystalline form B as defined herein or a mixture thereof with crystalline form A and/or the amorphous form of compound I. The term "effective amount" denotes an amount of crystalline form B or a mixture as defined above by referring the total amount of compound I, said amount being sufficient for controlling harmful pests on cultivated plants or in the protection of materials and which does not result in a substantial damage to the treated plants. Such an amount can vary in a broad range and is dependent on various factors, such as the animal pests' species to be controlled, the treated cultivated plant or material, the climatic conditions and the specific mixture used.

The crystalline form B as defined herein and the mixtures of crystalline form B with other forms as defined herein can be converted into customary types of agrochemical compositions, e.g. solutions, emulsions, suspensions, dusts, powders, pastes, granules, pressings, capsules, and mixtures thereof. Examples for composition types are suspensions (e.g. SC, OD, FS), emulsifiable concentrates (e.g. EC), emulsions (e.g. EW, EO, ES, ME), capsules (e.g. CS, ZC), pastes, pastilles, wettable powders or dusts (e.g. WP, SP, WS, DP, DS), pressings (e.g. BR, TB, DT), granules (e.g. WG, SG, GR, FG, GG, MG), insecticidal articles (e.g. LN), as well as gel formulations for the treatment of plant propagation materials such as seeds (e.g. GF). These and further compositions types are defined in the "Catalogue of pesticide formulation types and international coding system", Technical Monograph No. 2, 6th Ed. May 2008, CropLife International.

The compositions are prepared in a known manner, such as described by Mollet and Grube- mann, Formulation technology, Wiley VCH, Weinheim, 2001 ; or Knowles, New developments in crop protection product formulation, Agrow Reports DS243, T&F Informa, London, 2005.

Suitable auxiliaries, solvents, liquid carriers, solid carriers, fillers, surfactants, adjuvants, thickeners, bactericides, anti-foaming agents, colorants and tackifiers, which may be used in the context of the agrochemical compositions can be found, e.g., in WO 2007/006670,

WO 2013/024008 or WO 2014/053407.

Details regarding the preparation of the above mentioned types of agrochemical compositions may also be found in WO 2007/006670, WO 2013/024008 or WO 2014/053407.

The agrochemical compositions generally comprise between 0.01 and 95%, preferably between 0.1 and 90%, and in particular between 0.5 and 75%, by weight of crystalline form B or a mixture thereof with crystalline form A and/or the amorphous form of compound I, based on the total weight of the composition. The crystalline form B or the mixtures containing crystalline form B as defined herein are employed in a purity of from 90% to 100%, preferably from 95% to 100% (according to NMR spectrum).

In one embodiment, a suspoconcentration (SC) is preferred for the application in crop protection. In one sub-embodiment thereof, the SC agrochemical composition comprises between 50 to 500 g/L (grams per Liter), or between 100 and 250 g/L, or 100 g/L or 150g/L or 200g/L or 250 g/L of crystalline form B or a mixture thereof with other forms as defined herein.

Water-soluble concentrates (LS), Suspoemulsions (SE), flowable concentrates (FS), powders for dry treatment (DS), water-dispersible powders for slurry treatment (WS), water-soluble powders (SS), emulsions (ES), emulsifiable concentrates (EC) and gels (GF) are usually employed for the purposes of treatment of plant propagation materials, particularly seeds. Details in this regard may also be found in WO 2007/006670, WO 2013/024008 or WO 2014/053407.

Crystalline form B of compound I and mixtures thereof with crystalline form A and/or the amorphous form of compound I are effective through both, contact and ingestion, and may be applied as disclosed in WO 2007/006670, WO 2013/024008 or WO 2014/053407. Preferred is the application on crops. Specific crops as well as typical pests to be controlled in connection with these crops are disclosed e.g. in WO 2014/053407

The crystalline form B and the mixtures thereof with other crystalline forms of compound I as defined herein are employed as such or in form of compositions by treating the insects or the plants, plant propagation materials, such as seeds, soil, surfaces, materials or rooms to be pro- tected from insecticidal attack with an insecticidally effective amount. Seed treatment is particularly preferred.

The application can be carried out both before and after the infection of the plants, plant propagation materials, such as seeds, soil, surfaces, materials or rooms by the insects. Details in this regard are provided in WO 2007/006670, WO 2013/024008 or WO 2014/053407.

In the context of the method of contacting the invertebrate pests, in particular insects, acarids or nematodes, or their food supply, habitat, breeding grounds or their locus with a pesticidally effective amount of crystalline form B or a mixture thereof with other forms, explanations are also provided in WO 2007/006670, WO 2013/024008 or WO 2014/053407. The crystalline form B and the mixtures thereof with other forms of compound I according to the invention may also be applied against non-crop insect pests, such as ants, termites, wasps, flies, mosquitos, crickets, or cockroaches. For use against said non-crop pests, the compounds and mixtures according to the invention are preferably used in a bait composition as described in WO 2014/053407.

The crystalline form B and the mixtures of crystalline form B with other forms of compound I as defined above may also be applied in combination with a further pesticidally active compound such as a biopesticide. Such mixtures are described e.g. in WO 2014/053407. In a second aspect, the present invention relates to a process 1 for converting the above described crystalline form B of compound I into crystalline form A of compound I, which has already been described in WO 2013/135606.

In one embodiment, the present invention relates to a process for converting the crystalline form B of compound I into a crystalline form A of compound I, which, in an X-ray powder diffractogram at 25°C and Cu-Κα radiation, shows at least four of the ten following reflexes, given as 2Θ values: 9.31 , 1 1.22, 15.50, 15.79, 17.16, 18.38, 18.74, 18.98, 26.23, 26.58, the process comprising the steps of

(a) forming a dispersion of the crystalline form B of compound I in a solvent selected from aqueous solvents, organic solvents and mixtures thereof; and

(b) stirring or shaking the dispersion at a temperature of at least 0°C.

As regards the characterization of the crystalline form A of compound I in the X-ray powder diffractogram, similar considerations apply as indicated above. A skilled person knows that the above 2Θ values may be understood as being within a certain error margin of ±0.2, preferably ±0.1 , more preferably ±0.05. It is preferred, however, that the above 2Θ values represent the exact values of the reflexes, which can be observed in the diffractogram.

Thus, crystalline form A can be detected on the basis of at least four of the ten reflexes, which are provided above for crystalline form A, i.e. 9.31 , 1 1.22, 15.50, 15.79, 17.16, 18.38, 18.74, 18.98, 26.23, 26.58, in an X-ray powder diffractogram. It is preferred that at least six, frequently at least seven or eight, preferably nine of the ten reflexes provided above for crystalline form A can be observed. It is particularly preferred that the following four reflexes are observed, given as 2Θ values: 15.50, 15.79, 26.23, 26.58, preferably the following six reflexes: 1 1.22, 15.50, 15.79, 18.38, 26.23, 26.58. Most preferably, all ten of the above listed reflexes can be observed.

The present invention relates in one preferred embodiment to a process for converting the crystalline form B of compound I, which, in an X-ray powder diffractogram at 25°C and Cu- Ka radiation, shows at least six, preferably at least eight, of the following ten reflexes, given as 2Θ values: 7.01 , 8.26, 9.16, 10.99, 12.21 , 13.93, 16.46, 17.22, 18.28, 20.89,

into a crystalline form A of compound I, which, in an X-ray powder diffractogram at 25°C and Cu-Κα radiation, shows at least six, preferably at least eight, of the following ten reflexes, given as 2Θ values: 9.31 , 1 1 .22, 15.50, 15.79, 17.16, 18.38, 18.74, 18.98, 26.23, 26.58,

the process comprising the steps of

(a) forming a dispersion of the crystalline form B of compound I in a solvent selected from aqueous solvents, organic solvents and mixtures thereof; and

(b) stirring or shaking the dispersion at a temperature of at least 0°C. The present invention relates in a particularly preferred embodiment to a process for converting

the crystalline form B of compound I, which, in an X-ray powder diffractogram at 25°C and Cu- Ka radiation, shows at least the following ten reflexes, given as 2Θ values: 7.01 , 8.26, 9.16, 10.99, 12.21 , 13.93, 16.46, 17.22, 18.28, 20.89,

into a crystalline form A of compound I, which, in an X-ray powder diffractogram at 25°C and Cu-Κα radiation, shows at least the following ten reflexes, given as 2Θ values: 9.31 , 1 1.22, 15.50, 15.79, 17.16, 18.38, 18.74, 18.98, 26.23, 26.58,

the process comprising the steps of

(a) forming a dispersion of the crystalline form B of compound I in a solvent selected from aqueous solvents, organic solvents and mixtures thereof; and

(b) stirring or shaking the dispersion at a temperature of at least 0°C.

If the process 1 is performed with crystalline form B in pure form, i.e. if, in step (a) of process 1 , crystalline form B is not provided as a mixture with the crystalline form A, partial and complete conversion of crystalline form B into crystalline form A can thus be confirmed, if crystalline form A can be detected in an X-ray powder diffractogram as described above. If the characteristic reflexes of crystalline form B can no longer be detected, complete conversion has been achieved.

In a preferred embodiment, the crystalline form A is obtained in a non-solvated crystalline form.

In a preferred embodiment of process 1 of the present invention, crystalline form B of compound I is dispersed in the solvent, in step (a) of the process, in a concentration of gram crystalline form B per gram solvent in the range of from 0.05 g/g to 1.0 g/g, preferably 0.1 g/g to 1 .0 g/g. In another preferred embodiment, crystalline form B of compound I is dispersed in the sol- vent, in step (a) of the process, in a concentration of gram crystalline form B per gram solvent of from 0.1 to 0.8 g/g, preferably from 0.2 to 0.7 g/g, most preferably from 0.3 to 0.6 g/g.

It has surprisingly been found that the crystalline form B may be present in the dispersion in very high concentrations, so that the process can be performed in a cost-efficient manner already for the reason that only low amounts of solvent are required. The dispersion may also be referred to as slurry. Preferably, in step (a) of process 1 , a dispersion or slurry of crystalline form B of compound I is prepared, wherein crystalline form B is provided in particulate form, e.g. as a powder, as crystals, as a granulate or as a comminuted solidified melt and then mixed with the solvent, optionally under stirring.

In another preferred embodiment, crystalline form B of compound I is provided, in step (a) of process 1 , in chemically pure form. Thus, the compound I being in the crystalline form B has a purity of at least 95%, preferably at least 97%, more preferably at least 98%, most preferably at least 99%. A high purity is advantageous for crystallization in general, and it should also be advantageous for the conversion of crystalline form B into crystalline form A because crystallization of crystalline form A is enhanced.

In another preferred embodiment, the crystalline form B of compound I is provided, in step (a) of process 1 , as a mixture with the crystalline form A of compound I. Alternatively, the crystalline form B of compound I may also be provided as a mixture with compound I in amorphous form, or as mixture with the crystalline form A and the amorphous form. In general, the process can be performed starting from a mixture of amorphous and crystalline forms of compound I, as long as the mixture also contains crystalline form B, preferably in an amount of at least 1 wt.-%, more preferably at least 20 wt.-%, still more preferably at least 50 wt.-%, most preferably at least 80 wt.-%, particularly preferably at least 99 wt.-%. It is preferred that the amorphous form is only present in such mixtures in minor amounts, e.g. in an amount of less than 10 wt.-% or less than 5 wt.-% based on the total weight of the mixture, or not contained in the mixtures at all. In any case and irrespective of whether the compound I is provided exclusively as crystalline form B or as a mixture with crystalline form A and/or the amorphous form of compound I, it is advantageous, if the compound I has a high chemical purity as already indicated above, i.e. a purity of at least 95%, preferably at least 97%, more preferably at least 98%, most preferably at least 99%.

If crystalline form B of compound I is provided, in step (a) of process 1 , as a mixture with the crystalline form A of compound I, the above provided preferred concentrations are also relevant for such mixtures. Accordingly, it is preferred that a mixture of crystalline form B and crystalline form A, and optionally compound I in amorphous form, is dispersed in the solvent, in step (a) of process 1 , in a concentration of gram mixture per gram solvent in the range of from 0.05 g/g to 1 .0 g/g, preferably 0.1 g/g to 1.0 g/g. In another preferred embodiment, the mixture is dispersed in the solvent, in step (a) of the process, in a concentration of gram mixture per gram solvent of from 0.1 to 0.8 g/g, preferably from 0.2 to 0.7 g/g, most preferably from 0.3 to 0.6 g/g.

If crystalline form B is provided as a mixture with crystalline form A, the crystalline form B and the crystalline form A are preferably present in said mixture in a weight ratio range of from 90:10 to 10:90, preferably from 60:40 to 40:60. Alternatively, the weight ratios of crystalline form B to crystalline form A may e.g. be in the range of from 10:90 to 40:60 or from 90:10 to 60:40. It is preferred that the mixture shows, in an X-ray powder diffractogram at 25°C and Cu-K _Q radiation, at least four of the ten following reflexes, given as 2Θ values: 7.01 , 8.26, 9.16, 10.99, 12.21 , 13.93, 16.46, 17.22, 18.28, 20.89, and at least four of the ten following reflexes, given as 2Θ values: 9.31 , 1 1 .22, 15.50, 15.79, 17.16, 18.38, 18.74, 18.98, 26.23, 26.58. It is more preferred that a mixture of crystalline form B with crystalline form A shows, in an X-ray powder

diffractogram at 25°C and Cu-K _Q radiation, at least six, especially at least eight, of the following ten reflexes, given as 2Θ values: 7.01 , 8.26, 9.16, 10.99, 12.21 , 13.93, 16.46, 17.22, 18.28, 20.89, and at least six, especially at least eight, of the following ten reflexes, given as 2Θ values: 9.31 , 1 1 .22, 15.50, 15.79, 17.16, 18.38, 18.74, 18.98, 26.23, 26.58. It is particularly preferred that a mixture of crystalline form B with crystalline form A shows, in an X-ray powder

diffractogram at 25°C and Cu-K _Q radiation, at least the following ten reflexes, given as 2Θ values: 7.01 , 8.26, 9.16, 10.99, 12.21 , 13.93, 16.46, 17.22, 18.28, 20.89, and at least the following ten reflexes, given as 2Θ values: 9.31 , 1 1 .22, 15.50, 15.79, 17.16, 18.38, 18.74, 18.98, 26.23, 26.58.

In another preferred embodiment, the solvent, wherein crystalline form B is dispersed in step (a) of process 1 , is an aprotic organic solvent. Preferably, the aprotic solvent is selected from the group consisting of toluene, xylene, diethyl ether, diisopropyl ether, methyl tert-butyl ether, acetonitrile, ethyl acetate and butyl acetate. Particularly preferably, the aprotic solvent is ethyl acetate or butyl acetate. It is also preferred that mixtures of aprotic solvents, e.g. a mixture of ethyl acetate and butyl acetate, are used. Alternatively, chlorinated organic solvents, such as chloroform or methylene chloride may be used as solvents. In another preferred embodiment, the solvent, wherein crystalline form B is dispersed in step (a) of process 1 , is an aqueous solvent. Preferably, the aqueous solvent is an aqueous salt solution, an aqueous acid or base solution or water. Particularly preferably, the aqueous solvent is water.

It is also preferred that mixtures of aqueous solvents with organic solvents are used. For example, it is preferred that crystalline form B is dispersed in a mixture of water with at least one water-miscible solvent, wherein the water-miscible solvent is preferably selected from the group consisting of tetrahydrofuran, acetonitrile, dioxane, acetone, methanol, ethanol, n-propanol, iso- propanol, tert-butanol or 2-methylbutan-2-ol, butanone, dimethylformamide, dimethylacetamide, N-methyl-2-pyrrolidone and dimethyl sulfoxide.

Step (b) of the process 1 of the present invention is typically performed for a duration time, which is sufficient to achieve at least partial conversion of the crystalline form B into crystalline form A. As already indicated above, partial conversion may result in the formation of a mixture of crystalline forms B and A, and if the process is started from a mixture of crystalline forms B and A, partial conversion may result in an enrichment of crystalline form A in said mixture. The formation of crystalline form A is preferably observed by determining the reflexes in an X-ray powder diffractogram at 25°C and Cu-K _Q radiation of a sample and comparing them with the characteristic reflexes for crystalline form A as described above. When the process is performed starting from a mixture of crystalline forms B and A, enrichment of crystalline form A may be observed by determining the reflexes in an X-ray powder diffractogram at 25°C and Cu-K _Q radiation of a sample, and comparing the 2Θ values with the 2Θ values of the diffractogram of pure samples of crystalline forms A and B. Mixtures of crystalline forms B and A will result in reflexes, which are characteristic for both, crystalline forms B and A. If crystalline form A has been enriched, the diffractogram will predominantly show the reflexes, which are characteristic for crys- talline form A, i.e. at least four of the following ten reflexes, given as 2Θ values: 9.31 , 1 1.22, 15.50, 15.79, 17.16, 18.38, 18.74, 18.98, 26.23, 26.58, preferably at least six, more preferably at least eight, in particular all of these ten reflexes.

In a preferred embodiment of the invention, step (b) of process 1 is performed for a duration time, which is sufficient for a complete conversion of crystalline form B into crystalline form A. The formation of crystalline form A can again be observed by determining the reflexes in an X- ray powder diffractogram as indicated above. On the other hand, complete conversion, i.e. complete degradation of crystalline form B, may be determined in a diffractogram, if the characteristic reflexes of crystalline form B, i.e. at least four of the following ten reflexes, given as 2Θ values: 7.01 , 8.26, 9.16, 10.99, 12.21 , 13.93, 16.46, 17.22, 18.28, 20.89, can no longer be de- tected. In particular, complete conversion can be determined, if the following six reflexes of crystalline form B, i.e. 7.01 , 8.26, 9.16, 10.99, 12.21 , and 13.93, can no longer be detected. Most preferably, none of the following ten reflexes can be detected: 7.01 , 8.26, 9.16, 10.99, 12.21 , 13.93, 16.46, 17.22, 18.28, 20.89.

Stirring or shaking is advantageous for enhancing the conversion of crystalline form B into crystalline form A. In principal, it is advantageous if the solvent and the solid particles of crystalline form B are thoroughly mixed because it is then possible that small amounts of crystalline form B are dissolved and can recrystallize as crystalline form A. Said recrystallization principally also occurs, if a dispersion of crystalline form B is allowed to stand, but the process is then rather slow. It is therefore preferred according to the present invention that the dispersion is stirred or shaken in step (b) of process 1 . Stirring is particularly preferred, and may be performed, e.g., at 30 to 50 rpm.

In a preferred embodiment, step (b) is performed at a temperature in the range of 0°C to 80°C, preferably in the range of 0°C to 60°C. Suitable temperatures may thus e.g. be from 20°C to 30°C or from 45°C to 55°C. In another preferred embodiment, step (b) is performed for a duration time of at least 10 minutes, preferably at least one hour, more preferably at least 1 day, most preferably from 1 day to 10 days. Suitable duration times may thus e.g. be from 1 hour to 2 hours or from 2 hours to 6 hours or from 1 day to 2 days. If higher temperatures are applied, the reaction times may be shorter. It is preferred that step (b) is performed at a temperature in the range of 0°C to 80°C, preferably in the range of 0°C to 60°C, and for a duration time of at least 10 minutes, preferably at least one hour, more preferably at least 1 day, most preferably from 1 day to 10 days. For example, the reaction may be performed at 20°C to 30°C for a duration time of 1 hour to 2 hours or 2 hours to 6 hours. In certain situations, it may be advantageous to perform the reaction at 45°C to 55°C for a duration time of 6 days to 8 days.

It has been found that, if organic solvents, preferably aprotic organic solvents are used, complete conversion of crystalline form B into crystalline form A can be achieved at particularly low temperatures within short duration times. On the other hand, if aqueous solvents are used, it may be required to apply higher temperatures and longer duration times.

It is therefore a preferred embodiment of the invention that step (b) is performed at a tempera- ture in the range of 0°C to 60°C, preferably in the range of 0°C to 50°C, more preferably in the range of 20°C to 30°C, and for a duration time of at least 10 minutes, preferably from 1 hour to 12 hours, more preferably from 1 hour to 3 hours, if, in step (a), the solvent is an organic solvent, preferably an aprotic organic solvent, e.g. ethyl acetate or butyl acetate. It is particularly preferred that step (b) is performed at room temperature for a duration time of 1 hour to 3 hours in ethyl acetate or butyl acetate.

It is also a preferred embodiment of the invention that, in step (a), the solvent is water or a mixture of water with at least one water miscible solvent selected from the group consisting of tetrahydrofuran, acetonitrile, dioxane, acetone, methanol, ethanol, n-propanol, isopropanol, tert- butanol or 2-methylbutan-2-ol, butanone, dimethylformamide, dimethylacetamide, N-methyl-2- pyrrolidone and dimethyl sulfoxide, and step (b) is performed at a temperature in the range of 20 to 60°C, preferably in the range of 40 to 60°C, and for a duration time from 1 day to 10 days, preferably 6 days to 8 days. It is particularly preferred that step (b) is performed at a temperature of about 45 to 55°C and for a duration time of about 1 week in water. Under these reaction conditions, complete conversion of crystalline form B into crystalline form A can usually be achieved. It has been found that complete conversion of crystalline form B into crystalline form A can also be achieved at lower temperatures, e.g. at 20 to 30°C, and shorter duration times of at least one day, if crystalline form B is provided as a mixture with crystalline form A in step (a) of process 1 .

Isolation of crystalline form A from the dispersion obtained in step (b) of process 1 is principally possible by means of filtration. In order to obtain pure crystalline form A, i.e. not a mixture of crystalline form B and crystalline form A, it is preferred to isolate crystalline form A by filtration after complete conversion of crystalline form B into crystalline form A. The filter residue may then be dried in vacuum, and the resulting crystalline form A can be stored and used for commercial purposes. In a third aspect, the present invention relates to a process 2 for converting the above described crystalline form B of compound I into crystalline form A of compound I. In one embodiment, the present invention relates to a process for converting the crystalline form B of compound I into a crystalline form A of compound I, which, in an X-ray powder diffractogram at 25°C and Cu-K _Q radiation, shows at least four of the ten following reflexes, given as 2Θ values: 9.31 , 1 1 .22, 15.50, 15.79, 17.16, 18.38, 18.74, 18.98, 26.23, 26.58, the process comprising the steps of

(a) forming a solution of the crystalline form B of compound I in a solvent selected from aqueous solvents, organic solvents and mixtures thereof, optionally under heating; and

(b) causing crystallization by evaporating the solvent from the solution and/or cooling the solution.

In a preferred embodiment, the present invention relates to a process for converting the crystalline form B of compound I, which, in an X-ray powder diffractogram at 25°C and Cu- Ka radiation, shows at least six, preferably at least eight, of the following ten reflexes, given as 2Θ values: 7.01 , 8.26, 9.16, 10.99, 12.21 , 13.93, 16.46, 17.22, 18.28, 20.89,

into a crystalline form A of compound I, which, in an X-ray powder diffractogram at 25°C and Cu-Κα radiation, shows at least six, preferably at least eight, of the following ten reflexes, given as 2Θ values: 9.31 , 1 1 .22, 15.50, 15.79, 17.16, 18.38, 18.74, 18.98, 26.23, 26.58,

the process comprising the steps of

a) forming a solution of the crystalline form B of compound I in a solvent selected from aqueous solvents, organic solvents and mixtures thereof, optionally under heating; and

(b) causing crystallization by evaporating the solvent from the solution and/or cooling the so- lution.

In a particularly preferred embodiment, the present invention relates to a process for converting

the crystalline form B of compound I, which, in an X-ray powder diffractogram at 25°C and Cu- Ka radiation, shows at least the following ten reflexes, given as 2Θ values: 7.01 , 8.26, 9.16, 10.99, 12.21 , 13.93, 16.46, 17.22, 18.28, 20.89,

into a crystalline form A of compound I, which, in an X-ray powder diffractogram at 25°C and Cu-Κα radiation, shows at least the following ten reflexes, given as 2Θ values: 9.31 , 1 1 .22, 15.50, 15.79, 17.16, 18.38, 18.74, 18.98, 26.23, 26.58,

the process comprising the steps of

a) forming a solution of the crystalline form B of compound I in a solvent selected from aqueous solvents, organic solvents and mixtures thereof, optionally under heating; and

(b) causing crystallization by evaporating the solvent from the solution and/or cooling the solution.

With regard to the characterization and detection of crystalline form A, the same considera- tions apply as indicated above for process 1.

In a preferred embodiment, crystalline form A is obtained in a non-solvated crystalline form. Crystalline form B may be provided in particulate form to be dissolved in step (a) of process 2, e.g. as a powder, as crystals, as a granulate or as a comminuted solidified melt. Crystalline form B may be provided either alone or as a mixture with crystalline form A and/or the amorphous form.

After the solution has been formed in step (a) of process 2, it can no longer be distinguished between the amorphous or crystalline forms of compound I. The concentration of compound I will depend on the solubility of the amorphous and crystalline forms of compound I in the solvent. A skilled person will easily find suitable concentrations by testing the solubility of crystalline form B or the mixture thereof with crystalline form A and/or the amorphous form in small amounts of the selected solvent and then adding additional solvent or heating the solvent, if the substance is not dissolved, or evaporating parts of the solvent, if the substance is directly dis- solved. In a preferred embodiment, the concentration of crystalline form B or a mixture as defined above in gram per liter of the solution may be in the range of 0.1 to 10 mg/L, preferably 0.5 to 5 mg/L, more preferably 1.0 to 3.0 mg/L. In another preferred embodiment, the concentration in the solution may be in the range of 0.05 to 3 mg/l, preferably 0.5 to 2.5 mg/L. In yet another preferred embodiment, the concentration in the solution may be in the range of 1 .0 to 5.0 mg/L, preferably in the range of 1 .5 to 2.5 mg/L.

In a preferred embodiment, the formation of the solution according to step (a) of process 2 is achieved under heating, preferably at 30 to 100°C, e.g. at 70 to 90°C or at 30 to 50°C, more preferably at 40 to 80°C, most preferably at 50 to 60°C. Furthermore, the formation of the solution may be enhanced by stirring or shaking, preferably by stirring at 30 to 50 rpm.

With regard to the chemical purity, the provision of crystalline form B either alone or as a mixture with crystalline form A and/or the amorphous form, the same applies as indicated above for process 1 .

Thus, it is a preferred embodiment that crystalline form B of compound I is provided in step (a) of process 2 in chemically pure form, i.e. in a purity of at least 95%, preferably at least 97%, more preferably at least 98%, most preferably at least 99%.

In another preferred embodiment, the crystalline form B of compound I is provided, in step (a) of process 2, as a mixture with the crystalline form A of compound I, as a mixture with compound I in amorphous form, or as mixture with the crystalline form A and the amorphous form. Irrespective of whether the compound I is provided exclusively as crystalline form B or as a mix- ture with crystalline form A and/or the amorphous form, it is advantageous, if the compound I has a high chemical purity as already indicated above.

If crystalline form B is provided as a mixture with crystalline form A, the crystalline form B and the crystalline form A are preferably present in said mixture in a weight ratio range of from 90:10 to 10:90, preferably from 60:40 to 40:60. Furthermore, it is preferred that said mixture shows, in an X-ray powder diffractogram at 25°C and Cu-K _Q radiation, at least four of the ten following reflexes, given as 2Θ values: 7.01 , 8.26, 9.16, 10.99, 12.21 , 13.93, 16.46, 17.22, 18.28, 20.89, and at least four of the ten following reflexes, given as 2Θ values: 9.31 , 1 1.22, 15.50, 15.79, 17.16, 18.38, 18.74, 18.98, 26.23, 26.58. It is more preferred that a mixture of crystalline form B with crystalline form A shows, in an X-ray powder diffractogram at 25°C and Cu-K _Q radiation, at least six, especially at least eight, of the following ten reflexes, given as 2Θ values: 7.01 , 8.26, 9.16, 10.99, 12.21 , 13.93, 16.46, 17.22, 18.28, 20.89, and at least six, especially at least eight, of the following ten reflexes, given as 2Θ values: 9.31 , 1 1.22, 15.50, 15.79, 17.16, 18.38, 18.74, 18.98, 26.23, 26.58. It is particularly preferred that a mixture of crystalline form B with crystalline form A shows, in an X-ray powder diffractogram at 25°C and Cu-K _Q radiation, at least the follow- ing ten reflexes, given as 2Θ values: 7.01 , 8.26, 9.16, 10.99, 12.21 , 13.93, 16.46, 17.22, 18.28, 20.89, and at least the following ten reflexes, given as 2Θ values: 9.31 , 1 1.22, 15.50, 15.79, 17.16, 18.38, 18.74, 18.98, 26.23, 26.58.

In a preferred embodiment, the solvent, which is used in step (a) of process 2, is an organic solvent, preferably an aprotic organic solvent, more preferably an aprotic solvent selected from the group consisting of toluene, xylene, diethyl ether, diisopropyl ether, methyl tert-butyl ether, acetonitrile, ethyl acetate and butyl acetate. Mixtures of these aprotic organic solvents are also preferred. Acetonitrile is particularly preferred. Alternatively, chlorinated organic solvents, such as chloroform or methylene chloride may be used as solvents. Methylene chloride is particularly preferred.

Crystallization of crystalline form A may be caused by evaporating the solvent from the solution or cooling the solution. Evaporation is preferably achieved under reduced pressure at 30 to 40°C. It is preferred that the solvent is removed only to some extent, e.g. that not more than half of the volume of the solvent is removed. Cooling is preferably to be understood as cooling to a temperature of 10°C or less, preferably 0°C or less. Preferably, crystallization is caused by evaporating the solvent to some extent, e.g. about half of the volume of the solvent, and then cooling the solution, preferably to a temperature of 10°C or less, more preferably to a temperature of 0°C or less. If solids are formed already upon evaporating the solvent, the solids may be collected, and the mother liquor may then be cooled as indicated above, and the formed solids may again be collected. Typically, the solids are collected by filtration.

Crystallization may be further enhanced, if seed crystals of crystalline form A are added to the solution.

In a preferred embodiment, complete conversion of crystalline form B into crystalline form A is achieved. This may be observed by X-ray powder diffraction as described above for process 1 . Accordingly, the filter residue, which can be obtained as indicated above, typically represents pure crystalline form A, which may be dried in vacuum and then stored and used for commercial purposes.

The following figures and examples further illustrate the present invention.

Figure 1 shows an X-ray powder diffractogram of crystalline form B of compound I.

Figure 2 shows an X-ray powder diffractogram of crystalline form A of compound I versus an X-ray powder diffractogram of crystalline form B of compound I.

Figure 3 shows a DSC curve of crystalline form B of compound I.

Figure 4 shows a DSC curve of crystalline form A of compound I.

Figure 5 shows the solubility of crystalline form B of compound I versus crystalline form A of compound I in water.

Figure 6 shows the conversion of crystalline form B into crystalline form A of compound I in ethyl acetate at different temperatures after 1 week in X-ray powder diffractograms.

Figure 7 shows the conversion of crystalline form B into crystalline form A of compound I in water at different temperatures after 1 week in X-ray powder diffractograms.

Examples Analytics

The X-ray powder diffractograms (XRPD) reported herein and displayed in Figures 1 , 2, 6 and 7 were recorded using a Panalytical X ^' Pert Pro diffracto meter (manufacturer: Panalytical) in reflection geometry in the range from 2Θ =3°-35°C with increments of 0,0167°C using Cu-Ka radiation ( at 25°C). The recorded 2Θ values were used to calculate the stated interplanar spacings d. The intensity of the peaks (y-axis: linear intensity counts) is plotted versus the 2Θ angle (x-axis in degrees 2Θ).

DSC was performed on a Mettler Toledo DSC 823e module. The samples were placed in crimped but vented aluminum pans. The sample size in each case was 5 to 10 mg. The thermal behavior was analyzed in the range of 30-300°C. The heating rate was 25°C/min. The samples were purged with a stream of nitrogen during the experiment.

Preparation Examples

Example P1 : Crystalline form B of 2-(3-chloro-2-pyridyl)-N-[2-methyl-4-chloro-6-[(diethyl-A ⁴ - sulfanylidene)carbamoyl]phenyl]-5-(trifluoromethyl)pyrazole- 3-carboxamide

A boiling solution of 2-(3-chloro-2-pyridyl)-N-[2-methyl-4-chloro-6-[(diethyl-A ⁴ -sulfanyl- idene)carbamoyl]phenyl]-5-(trifluoromethyl)pyrazole-3-carbox amide (50g, obtainable by the process described in WO 2013/024008) in acetonitrile (200 ml.) was added in a dropwise fashion to a dewar bowl containing liquid nitrogen. After complete addition, the mixture was allowed to reach room temperature and the solids were collected by filtration. Drying in vacuum at 45°C over night yielded compound I (42.8 g) in crystalline form B.

The X-ray powder diffractogram of the obtained crystalline form B, measured at 25°C and Cu- Ka radiation, shows the following reflexes, given as 2Θ values: 7.01 , 8.26, 9.16, 10.99, 12.21 , 13.93, 16.46, 17.22, 18.28, 20.89. The diffractogram is shown in Figure 1 , and can be compared to the diffractogram of crystalline form A in Figure 2.

The DSC curve measured by differential scanning calorimetry at a scan rate of 25°C per minute, exhibits an exothermic peak with an onset temperature of about 77°C and a peak temperature of about 124°C, which is characteristic for crystalline form B. The complete DSC curve is shown in Figure 3. For comparison, the DSC curve of crystalline form A is provided in Figure 4. Solubility tests of crystalline form B in water show a solubility of about 2 mg/L. The results are shown in Figure 5 comparison to crystalline form A.

Conversion Examples

Example C1 : Studies for the conditions for the conversion of crystalline form B of 2-(3-chloro- 2-pyridyl)-N-[2-methyl-4-chloro-6-[(diethyl-A ⁴ -sulfanylidene)carbamoyl]phenyl]-5-

(trifluoromethyl)pyrazole-3-carboxamide into crystalline form A in an organic solvent A dispersion of crystalline form B of 2-(3-chloro-2-pyridyl)-N-[2-methyl-4-chloro-6-[(diethyl-A ⁴ - sulfanylidene)carbamoyl]phenyl]-5-(trifluoromethyl)pyrazole- 3-carboxamide (85 kg) in ethyl acetate (150 kg) was stirred at 40 rpm for 1 week at 0°C, room temperature and 50°C. The solids were in each case collected by filtration and dried in vacuum at 45°C.

The extent of the conversion of crystalline form B into crystalline form A is determined by comparing the X-ray powder diffractograms of the isolated solids with the X-ray powder

diffractograms of crystalline forms A and B, respectively, in pure form. The results are provided in Figure 6.

It has been found that the X-ray powder diffractograms, measured at 25°C and Cu-K _Q radiation, show, in each case, the characteristic reflexes of crystalline form A, given as 2Θ values: 9.31 , 1 1 .22, 15.50, 15.79, 17.16, 18.38, 18.74, 18.98, 26.23, 26.58, but no reflexes of crystalline form B indicating complete conversion of crystalline form B into crystalline form A. Example C2: Conversion of crystalline form B of 2-(3-chloro-2-pyridyl)-N-[2-methyl-4-chloro-6- [(diethyl-A ⁴ -sulfanylidene)carbamoyl]phenyl]-5-(trifluoromethyl)py razole-3-carboxamide into crystalline form A in ethyl acetate

A dispersion of crystalline form B of 2-(3-chloro-2-pyridyl)-N-[2-methyl-4-chloro-6-[(diethyl-A ⁴ - sulfanylidene)carbamoyl]phenyl]-5-(trifluoromethyl)pyrazole- 3-carboxamide (85 kg) in ethyl acetate (150 kg) was stirred at 40 rpm for 2 hours at room temperature. The solids were collected by filtration and dried in vacuum at 45°C.

The X-ray powder diffractogram, measured at 25°C and Cu-K _Q radiation, shows the character- istic reflexes of crystalline form A, given as 2Θ values: 9.31 , 1 1 .22, 15.50, 15.79, 17.16, 18.38, 18.74, 18.98, 26.23, 26.58, but no reflexes of crystalline form B indicating complete conversion of crystalline form B into crystalline form A within a duration time of only 2 hours.

Example C3: Studies for the conditions for the conversion of crystalline form B of 2-(3-chloro- 2-pyridyl)-N-[2-methyl-4-chloro-6-[(diethyl-A ⁴ -sulfanylidene)carbamoyl]phenyl]-5-

(trifluoromethyl)pyrazole-3-carboxamide into crystalline form A in an aqueous solvent

A dispersion of crystalline form B of 2-(3-chloro-2-pyridyl)-N-[2-methyl-4-chloro-6-[(diethyl-A ⁴ - sulfanylidene)carbamoyl]phenyl]-5-(trifluoromethyl)pyrazole- 3-carboxamide (85 kg) in water (150 kg) was stirred at 40 rpm for 1 week at room temperature and 50°C. The solids were in each case collected by filtration and dried in vacuum at 45°C.

The extent of the conversion of crystalline form B into crystalline form A is determined by comparing the X-ray powder diffractograms of the isolated solids with the X-ray powder

diffractograms of crystalline forms A and B, respectively, in pure form. The results are provided in Figure 7. It has been found that the X-ray powder diffractogram, measured at 25°C and Cu-K _Q radiation, shows, for the sample obtained after 1 week at 50°C, the characteristic reflexes of crystalline form A, given as 2Θ values: 9.31 , 1 1.22, 15.50, 15.79, 17.16, 18.38, 18.74, 18.98, 26.23, 26.58, but no reflexes of crystalline form B indicating complete conversion of crystalline form B into crystalline form A.

Furthermore, it has been found that the X-ray powder diffractogram, measured at 25°C and Cu-Κα radiation, shows, for the sample obtained after 1 week at room temperature, both, the characteristic reflexes of crystalline form A, given as 2Θ values: 9.31 , 1 1 .22, 15.50, 15.79, 17.16, 18.38, 18.74, 18.98, 26.23, 26.58, and the characteristic reflexes of crystalline form B , given as 2Θ values: 7.01 , 8.26, 9.16, 10.99, 12.21 , 13.93, 16.46, 17.22, 18.28, 20.89, indicating partial conversion of crystalline form B into crystalline form A.