Biogenic pyridine compounds and processes thereof

Abstract

The present disclosure provides a process for obtaining a compound of Formula (I) its salts and solvates thereof, preferably 2-(C1-C4)alkyl-5-(C1-C4)alkylpyridine, and more preferably 2-methyl-5-ethylpyridine from a plant based bioethanol The present disclosure further provides a process for obtaining pyridine carboxamide, particularly pyridine-3-carboxamide from the compound of Formula (I). The present disclosure provides 2-methyl-5-ethylpyridine, pyridine-3-carboxylic acid, ethyl pyridine-3-carboxylate and pyridine-3-carboxamide, independently having more than or equal to 98% of biogenic carbon.

Description

BIOGENIC PYRIDINE COMPOUNDS AND PROCESSES THEREOFFIELD OF INVENTION

[0001] The present invention relates to the field of biogenic pyridine compounds. The present invention in particular relates to a process of producing 2-methyl-5-ethylpyridine, and further relates to a process of producing pyridine-3-carboxamide.BACKGROUND OF INVENTION

[0002] Pyridine-3 -carboxamide, is an essential constituent of pyridine coenzymes in mammals. Though pyridine-3 -carboxamide is naturally found in plants and animal sources, deficiency of pyridine-3 -carboxamide and associated disease conditions is common in humans and is typically managed with pyridine-3-carboxamide supplements. Apart from the nutraceutical applications, pyridine-3-carboxamide is extensively used in cosmetics owing to its hair and skin conditioning properties. Overall, there is a constant demand for pyridine-3-carboxamide with considerable purity to be employed in nutraceutical and cosmeceutical formulations.

[0003] There are several routes for synthesizing pyridine-3 -carboxamide. The synthesis process involving 2-methyl-5-ethylpyridine (MEP) is one of favoured routes for synthesizing pyridine-3 -carboxamide. Given the need for synthesizing green pyridine-3 -carboxamide for nutraceutical and cosmeceutical applications, it is essential to develop a sustainable and economical process involving bio based starting materials, and intermediates, such as MEP and synthesize pyridine-3 -carboxamide with at least 98% biogenic carbon.SUMMARY OF THE INVENTION

[0004] In an aspect of the present invention, there is provided a process of obtaining a compound of Formula (I), its salts and solvates thereof, the process comprising the steps of: (a) providing aldehyde (A), (B) and / or (C) or a compound of Formula (II), its optical isomers, and solvates thereof, derived from a plant-based bioethanol; (b) reacting the aldehyde (A), (B) and / or (C) or the compound of Formula (II), its optical isomers and solvates thereof, with ammonia and anammonium salt catalyst in a semi-continuous or continuous reactor; (c) maintaining the reactor at a pressure in a range of 30-60 bar and a temperature in a range of 200-280°C during the reaction; and (d) producing bio-based compound of Formula (I), its salts and solvates thereof,Scheme-Iwherein, (A), (B) and (C) can be identical or different; preferably identical;R₁, R₂, and R₃ identical or different, preferably identical, are selected from linear orbranched (C₁-C₆)alkyl; R₄ is selected from linear or branched (C₁-C₆)alkyl;n is 1, 2 or 3; m is 1, 2 or 3;with the proviso that:- the ammonium salt catalyst is added in an amount in a range of 0.01 to 0.1 mole per mole of the aldehyde (A), (B) and / or (C) or the compound of Formula (II); - when m is 2 or 3 then the radicals R4 are identical or different, preferably different; R4 is positioned on one of the carbon atoms 2 to 6 of the pyridine core of the Formula (I); andthe process is optionally conducted from (A), (B), and / or (C) directly by combining step i) and ii) without isolating the intermediate compound of Formula (II).

[0005] In another aspect of the present invention, there is provided a process for producing pyridine carboxamide derivatives and preferably pyridine-3-carboxamide having more than or equal to 98%, more preferably more than or equal to 99%, better more than or equal to 99.5%, such as 100% biogenic carbon, the process according to Scheme-II comprising the steps of: (i) yielding alkylaldehyde particularly (C₁-C₆)alkylaldehyde preferably acetaldehyde from a plant-based bio alcohol particularly bio (C₁-C₆)alkanol such as bioethanol from sugarcane molasses, sugarcane juice or sugarcane syrup; (ii) converting the alkylaldehydepreferably acetaldehyde to a compound of Formula (II); (iii) reacting the compound of Formula (II) its optical isomers, salts and solvates thereof, with ammonia and an ammonium salt catalyst to produce a compound of Formula (I), its salts and solvates thereof; (iv) oxidizing the compound of Formula (I), its salts and solvates thereof with nitric acid to produce pyridine carboxylic acid and its salts, preferably pyridine-3 -carboxylic acid and its salts; (v) esterifying pyridine carboxylic acid and its salts preferably pyridine- 3 -carboxylic acid its salts and solvates thereof, to obtain (C₁-C₆)alkyl pyridinecarboxylate, particularly (C₁-C₆)alkyl pyridine-3-carboxylate preferably ethyl pyridine-3-carboxylate, butyl pyridine-3-carboxylate, isoamyl pyridine-3-carboxylate and (vi) aminolysis of the (C₁-C₆)alkyl pyridinecarboxylate, particularly (C₁-C₆)alkyl pyridine-3-carboxylate preferably ethyl pyridine-3-carboxylate, butyl pyridine-3-carboxylate, isoamyl pyridine-3-carboxylate to obtain pyridine carboxamide especially pyridine-3-carboxamide,wherein, n, m, q, R₁, R₂, R₃ and R₄ are as disclosed herein, preferably (C₁-C₄)alkyl such as methyl or ethyl, and R₅ represents a linear or branched (C₁-C₆)alkyl, more preferably (C₁-C₄)alkyl such as ethyl, and q represents m-1, preferably 1.

[0006] Particularly, the process according to the invention is according to Scheme-Ill comprising the steps of: (i) yielding acetaldehyde from a plant-basedbioethanol from sugarcane molasses, juice or sugarcane syrup; (ii) converting the acetaldehyde to a compound of Formula (Ila); (iii) reacting the compound of Formula (Ila) with ammonia and an ammonium salt catalyst to produce a compound of Formula (la); (iv) oxidizing the compound of Formula (la) with nitric acid to produce pyridine carboxylic acid and its salts, preferably pyridine-3 -carboxylic acid and its salts; (v) esterifying pyridine carboxylic acid and its salts preferably pyridine-3 -carboxylic acid to obtain (C₁-C₆)alkyl pyridinecarboxylate, particularly (C₁-C₆)alkyl pyridine-3-carboxylate preferably ethyl pyridine-3-carboxylate, butyl pyridine-3-carboxylate, isoamyl pyridine-3-carboxylate and (vi) aminolysis of the (C₁-C₆)alkyl pyridinecarboxylate, particularly (C₁-C₆)alkyl pyridine-3-carboxylate preferably ethyl pyridine-3-carboxylate to obtain pyridine carboxamide especially pyridine-3-carboxamide,Scheme-Illwherein n, m, q, R4, and R5 are as defined herein before in Scheme-II.

[0007] More particularly the process according to the invention is as follows according to Scheme-IV comprising the steps of: (i) yielding acetaldehyde from a plant-based bioethanol from sugarcane molasses, sugarcane juice or sugarcane syrup; (ii) converting the acetaldehyde to a compound of Formula (Ila); (iii)reacting the compound of Formula (Ila) with ammonia and an ammonium salt catalyst to produce a compound of Formula (lb); (iv) oxidizing the compound of Formula (lb) with nitric acid to produce pyridine carboxylic acid and its salts, preferably pyridine-3 -carboxylic acid and its salts; (v) esterifying the pyridine carboxylic acid and its salts preferably pyridine-3-carboxylic acid to obtain (C₁-C₆)alkyl pyridinecarboxylate, particularly (C₁-C₆)alkyl pyridine-3-carboxylate preferably ethyl pyridine-3-carboxylate, and (vi) aminolysis of the (C₁-C₆)alkyl pyridinecarboxylate, particularly (C₁-C₆)alkyl pyridine-3-carboxylate preferably ethyl pyridine-3-carboxylate to obtain pyridine carboxamide especially pyridine-3-carboxamide,Scheme -IVwherein, n, R₄ and R₅ is as defined herein before in Scheme-II, preferably R₄ are different, and more preferably represents (C₁-C₄)alkyl such as methyl or ethyl.

[0008] Preferably the process according to the invention is as follows according to Scheme-V comprising the steps of: (i) yielding acetaldehyde from a plant-based bioethanol from sugarcane molasses, sugarcane juice or sugarcane syrup; (ii) converting the acetaldehyde to a compound of Formula (lie); (iii) reacting the compound of Formula (lie) with ammonia and an ammonium salt catalyst to produce a compound of Formula (Ic); (iv) oxidizing the compound of Formula (Ic) with nitric acid to produce pyridine carboxylic acid and its salts, preferably pyridine-3 -carboxylic acid and its salts; (v) esterifying the pyridinecarboxylic acid and its salts preferably pyridine-3-carboxylic acid to obtain (C₁-C₆)alkyl pyridinecarboxylate, particularly (C₁-C₆)alkyl pyridine-3-carboxylate preferably ethyl pyridine-3-carboxylate, and (vi) aminolysis of the latter (C₁-C₆)alkyl pyridinecarboxylate, particularly (C₁-C₆)alkyl pyridine-3-carboxylate preferably ethyl pyridine-3-carboxylate to obtain pyridine carboxamide especially pyridine-3-carboxamide,Scheme-Vwherein R₄ and R₅ are as defined herein before in Scheme-IV.

[0009] In one another aspect of the present invention, there is provided pyridine carboxamide preferably pyridine-3-carboxamide, its salts and solvates thereof, having more than or equal to 98%, more preferably more than or equal to 99%, and better more than or equal to 99.5%, such as 100% biogenic carbon, wherein, the pyridine carboxamide preferably pyridine-3 -carboxamide is produced by the process as disclosed herein and has a purity of at least 98%; and the pyridine carboxamide preferably pyridine- 3 -carboxamide has a C14 content of at least 98 percent modem carbon (pMC) as measured by accelerator mass spectrometry.

[0010] In yet another aspect of the present invention, there is provided compounds of Formula (II), its optical isomers and salts thereof, especially 2,4,6- tri(C₁-C₆)alkyl-1,3,5-trioxane, (IIa), or (IIc) as defined herein, preferably 2,4,6-trimethyl- 1.3.5-trioxane, having more than or equal to 98%, more preferably more than or equal to 99%, and better more than or equal to 99.5%, such as 100% biogenic carbon; and the 2,4,6- tri(C₁-C₆)alkyl-1,3,5-trioxane preferably 2,4,6-trimethyl-1,3,5-trioxane has a C14 content of at least 98 percent modern carbon (pMC) as measured by accelerator mass spectrometry.

[0011] In more aspect of the present invention, there is provided compounds of Formula (la) as defined herein with m is equal to 2 and R4 are different, especially 2-(C₁-C₆)alkyl-5-(C₁-C₆)alkylpyridine preferably 2-methyl-5-ethylpyridine, having more than or equal to 98%, more preferably more than or equal to 99%, and better more than or equal to 99.5%, such as 100% biogenic carbon; wherein the 2-(C₁-C₆)alkyl-5-(C₁-C₆)alkylpyridine preferably 2-methyl-5-ethylpyridine is produced by the process as disclosed herein, and has a purity of at least 98%; and the 2-(C₁-C₆)alkyl-5-(C₁-C₆)alkylpyridine preferably 2-methyl-5-ethylpyridine has a C14 content of at least 98 percent modern carbon (pMC) as measured by accelerator mass spectrometry.

[0012] In more aspect of the present invention, there is provided 2-(C₁-C₆)alkyl-5-(C₁-C₆)alkylpyridine preferably 2-methyl-5-ethylpyridine, its salts and solvates thereof, having more than or equal to 98%, more preferably more than or equal to 99%, and better more than or equal to 99.5% such as 100% biogenic carbon; and the 2-(C₁-C₆)alkyl-5-(C₁-C₆)alkylpyridine preferably 2-methyl-5-ethylpyridine has a C14 content of at least 98 percent modern carbon (pMC) as measured by accelerator mass spectrometry.

[0013] In more aspect of the present invention, there is provided pyridine carboxylic acid, its salts and solvates thereof, preferably pyridine-3 -carboxylic acid its salts and solvates thereof, having more than or equal to 98%, more preferably more than or equal to 99%, and better more than or equal to 99.5%, such as 100% biogenic carbon; and the pyridine carboxylic acid its salts and solvates thereof, preferably pyridine-3 -carboxylic acid its salts and solvates thereof has a C14content of at least 98 percent modern carbon (pMC) as measured by accelerator mass spectrometry.

[0014] In more aspect of the present invention, there is provided (C₁-C₆)alkyl pyridine-3-carboxylate, preferably ethyl pyridine-3-carboxylate, butyl pyridine-3-carboxylate, or isoamyl pyridine-3-carboxylate, having more than or equal to 98%, more preferably more than or equal to 99%, and better more than or equal to 99.5% such as 100% biogenic carbon; and the (C₁-C₆)alkyl pyridine-3-carboxylate preferably ethyl pyridine-3-carboxylate, butyl pyridine-3-carboxylate, or isoamyl pyridine-3-carboxylate has a C14 content of at least 98 percent modern carbon (pMC) as measured by accelerator mass spectrometry.

[0015] These and other features, aspects, and advantages of the present subject matter will be better understood with reference to the following description and appended claims. This summary is provided to introduce a selection of concepts in a simplified form. This summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used to limit the scope of the claimed subject matter.DESCRIPTION OF THE INVENTION

[0016] Those skilled in the art will be aware that the present invention is subject to variations and modifications other than those specifically described. It is to be understood that the present invention includes all such variations and modifications. The invention also includes all such steps, features, compositions, and compounds referred to or indicated in this specification, individually or collectively, and any and all combinations of any or more of such steps or features.Definitions

[0017] For convenience, before further description of the present invention, certain terms employed in the specification, and examples are delineated here. These definitions should be read in the light of the remainder of the invention and understood as by a person of skill in the art. The terms used herein have the meanings recognized and known to those of skill in the art, however, for convenience and completeness, particular terms and their meanings are set forth below.

[0018] The articles “a”, “an” and “the” are used to refer to one or to more than one (i.e., to at least one) of the grammatical object of the article.

[0019] The terms “comprise” and “comprising” are used in the inclusive, open sense, meaning that additional elements may be included. It is not intended to be construed as “consists of only”.

[0020] The term “at least one” is used to mean one or more and thus includes individual components as well as mixtures / combinations.

[0021] Throughout this specification, unless the context requires otherwise the word “comprise”, and variations such as, “comprises” and “comprising”, will be understood to imply the inclusion of a stated element or step or group of elements or steps but not the exclusion of any other element or step or group of element or steps.

[0022] The term “including” is used to mean “including but not limited to”. “Including” and “including but not limited to” are used interchangeably.

[0023] The term “biogenic carbon” refers to the carbon that is stored in plants and organic matters in soil. Compounds having biogenic carbon comprise carbon that was derived from plant origin materials or animal-by products. For the purpose of the present disclosure, % biogenic carbon indicates the amount of carbon sourced from plant origin. The terms “biogenic carbon”, “bio-based carbon”, “renewable carbon”, “green carbon” shall be used interchangeably. The “% bio-based carbon” indicates the percentage carbon from “natural” (plant or animal by-product) sources versus “synthetic” (petrochemical) sources. For reference, 100 % bio-based carbon indicates that a material is entirely sourced from plants and 0 % bio-based carbon indicates that a material did not contain any carbon from plants or animal byproducts or is purely synthetic. A value in between represents a mixture of natural and fossil sources.

[0024] The term “solvates” refers to crystalline solids that contain stoichiometrically or non-stoichiometrically solvent molecules inside their crystal assembly. Solvents include but are not limited to water, alcohol, ether, nitriles, or combinations thereof. For the purpose of the present disclosure, the compounds ofthe present disclosure may be in the form of solvates. Solvates are referred to as hydrates when the solvent is water.

[0025] The term “salts” refers to an ionic compound formed by the neutralization reaction between an acid and a base. For the purpose of the present disclosure, the compounds may be in salt form with a suitable acid or a base, preferably the base may comprise an alkali metal (e.g. sodium or potassium) and alkali earth metal (e.g. calcium or magnesium) hydroxides, and organic bases, for example alkyl amines, arylalkyl amines and so on. Salts may include acid addition salts where appropriate which are sulphates, nitrates, phosphates, perchlorates, borates, hydrohalides, acetates, tartrates, maleates, fumarates, citrates, succinates, lactates, mesylates, trifluoroacetates, acetates, besylates, propionates, mandelates, hydrobromides, hydrochlorides, palmoates, methanesulphonates, tosylates, benzoates, salicylates, hydroxynaphthoates, benzenesulfonates, ascorbates, glycerophosphates, ketoglutarates and the like.

[0026] The term “optical isomers” also known as enantiomers refers to compounds having same molecular formulae but different three-dimensional orientations of the atoms in space. The optical isomers are mirror images, they interact with plane-polarized light and rotate the plane of polarized light either clock-wise or anticlockwise direction, represented as “D” and “L” isomers respectively. Compounds of the present disclosure may exist as optical isomers or diastereomers. Further compounds of the present disclosure may exist as geometric isomers, tautomers, or mixtures thereof.

[0027] The term “catalyst” refers to a substance that is added to a chemical reaction which increases the rate of the chemical reaction. The catalyst is added in minimal amounts, which does not undergo any chemical change itself but promotes a permanent chemical reaction. For the purpose of the present disclosure, the reaction of aldehyde (A), (B) and / or (C) or compound of Formula (II), (Ila), or (lie) and their optical isomers, and solvates thereof, is carried out in the presence of an ammonium salt as a catalyst. The ammonium salt is added in catalytic amount, in an amount in a range of 0.01 to 0.1 mole per mole of the aldehyde (A), (B) and / or (C) or the compound of Formula (II), (Ila), or (lie).

[0028] All percentages, parts and ratios are based upon the total weight of the compositions of the present invention unless otherwise indicated. Ratios, concentrations, amounts, and other numerical data may be presented herein in a range format. It is to be understood that such range format is used merely for convenience and brevity and should be interpreted flexibly to include not only the numerical values explicitly recited as the limits of the range, but also to include all the individual numerical values or sub-ranges encompassed within that range as if each numerical value and sub-range is explicitly recited. For example, a mole range of 1.5 to 3.5 should be interpreted to include not only the explicitly recited limits of about 1.5 to 3.5, but also to include sub-ranges, such as 2 to 3, 2.5 to 3.5 and so forth, as well as individual amounts, including fractional amounts, within the specified ranges, such as 1.85, 2.3 and 3.25, for example.

[0029] Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Although any methods and materials similar or equivalent to those described herein can be used in the practice or testing of the invention, the preferred methods and materials are now described. All publications mentioned herein are incorporated herein by reference.

[0030] The present invention is not to be limited in scope by the specific embodiments described herein, which are intended for the purposes of exemplification only. Functionally equivalent products, and methods are clearly within the scope of the invention, as described herein.Process of obtaining Biogenic pyridine compounds

[0031] Embodiments herein provide a process of obtaining a compound of Formula (I), (la), (lb) or (Ic), its salts and solvates thereof, the process comprising the steps of: (a) providing aldehyde (A), (B) and / or (C) or the compound of Formula (II), (Ila) or (lie) its optical isomers, and solvates thereof, derived from a plant-based bioethanol; (b) reacting the aldehyde (A), (B) and / or (C) or compound of Formula (II), (Ila), or (lie), its optical isomers, and solvates thereof, with ammonia and an ammonium salt catalyst in a semi-continuous or continuous reactor; (c) maintaining the reactor at a pressure in a range of 30-60 bar and a temperature in a range of 200-280°C during the reaction; and (d) producing bio-based compound of Formula (I), (la), (lb) or (Ic), its salts and solvates thereof;Scheme-Iwherein, (A), (B) and (C) can be identical or different, preferably identical;R₁, R₂, and R₃ identical or different, preferably identical, are selected from linear or branched (Ci-Ce)alkyl;R4 is selected from linear or branched (Ci-Ce)alkyl;n is 1, 2 or 3; m is 1, 2 or 3;with the proviso that:- the ammonium salt catalyst is added in an amount in a range of 0.01 to 0.1 mole per mole of the aldehyde (A), (B) and / or (C) or the compound of Formula (II), (Ila), or (lie);- when m is 2 or 3 then the radicals R4 are identical or different, preferably different;- R4 is positioned on one of the carbon atoms 2 to 6 of the pyridine core of the Formula (I); and- the process is optionally conducted from (A), (B), and / or (C) directly by combining step i) and ii) without isolating the intermediate compound of Formula (II), (Ila) or (lie).

[0032] In an embodiment of the present disclosure, there is provided a process of obtaining a compound of Formula (I), (la), (lb), or (Ic), the process comprising the steps of: (a) providing aldehyde (A), (B) and / or (C) or a compound of Formula (II), (Ila) or (lie), its optical isomers, and solvates thereof, derived from a plant-based bioethanol; (b) reacting the aldehyde (A), (B) and / or (C) or the compound of Formula (II), (Ila), or (lie), its optical isomers, and solvates thereof, with ammoniaand an ammonium salt catalyst in a continuous reactor; (c) maintaining the reactor at a pressure in a range of 30-60 bar and a temperature in a range of 200-280°C during the reaction; and (d) producing bio-based compound of Formula (I), its salts and solvates thereof, wherein, (A), (B) and (C) can be identical or different; preferably identical, Ri, R2, and R3 identical or different, preferably identical, are independently selected from linear or branched (Ci-C6)alkyl; R4 is selected from linear or branched (Ci-C6)alkyl; n is 1, 2 or 3; m is 1, 2 or 3; with the proviso that: the ammonium salt catalyst is added in an amount in a range of 0.01 to 0.1 mole per mole of the aldehyde (A), (B) and / or (C) or the compound of Formula (II), (Ila), or (lie); when m is 2 or 3 then the radicals R4 are identical or different; preferably different, R4 is positioned on one of the carbon atoms 2 to 6 of the pyridine core of the Formula (I), (la), (lb) or (Ic); and the process is optionally conducted from (A), (B), and / or (C) directly by combining step i) and ii) without isolating the intermediate compound of Formula (II), (Ila) or (lie).

[0033] In an embodiment of the present disclosure, there is provided a process of obtaining a compound of Formula (I), (la), (lb) or (Ic), as disclosed herein, wherein (A), (B) and (C) can be identical or different, preferably identical, Ri, R2, and R3 are independently selected from linear or branched (Ci-C6)alkyl, preferably from linear (Ci-C4)alkyl, more preferably is methyl.

[0034] In an embodiment of the present disclosure, there is provided a process of obtaining a compound of Formula (I), (la), (lb) or (Ic) as disclosed herein, wherein Ri, R2, R3 and R4 are independently selected from linear or branched (Ci-C4)alkyl, preferably linear (C1-C2) alkyl; n is 1 or 2, preferably 1; m is 1 or 2, preferably 2.

[0035] In an embodiment of the present disclosure, there is provided a process of obtaining a compound of Formula (I), or (la) as disclosed herein, wherein m is 1 or 2, preferably 2, R4 are different, and R4 is positioned on one of the carbon atoms 2 to 6 of the pyridine core of the Formula (I) or (la), preferably on carbon atoms 2 and 5 of the pyridine core of the Formula (I) or (la).

[0036] In an embodiment of the present disclosure, there is provided a process of obtaining a compound of Formula (I), (la), (lb) or (Ic) as disclosed herein, wherein the ammonium salt catalyst is added in an amount in a range of 0.02 to 0.08 moleper mole of the aldehyde (A), (B) and / or (C) or the compound of Formula (II). In another embodiment of the present disclosure, the ammonium salt catalyst is added in an amount in a range of 0.03 to 0.06 mole per mole of the aldehyde (A), (B) and / or (C) or the compound of Formula (II), (Ila) or (lie).

[0037] In an embodiment of the present disclosure, there is provided a process of obtaining a compound of Formula (I), (la), (lb) or (Ic) as disclosed herein, the process comprises the steps of: (i) providing aldehyde (A), (B) and / or (C), wherein (A), (B) and / or (C) may be identical or different, derived from plant-based bioethanol; (ii) reacting the aldehyde (A), (B) and / or (C), with ammonia and an ammonium salt catalyst in a semi-continuous or continuous reactor; (iii) maintaining the reactor at a pressure in a range of 30-60 bar and a temperature in a range of 200-280°C during the reaction; and (iv) producing bio-based compound of Formula (I), (la), (lb) or (Ic), its salts and solvates thereof, wherein Ri, R2, R3 and R4 are independently selected from linear or branched (Ci-C6)alkyl; n is 1, 2 or 3; m is 1, 2 or 3; with the proviso that: the ammonium salt catalyst is added in an amount in a range of 0.01 to 0.1 mole per mole of the aldehyde (A), (B) and / or (C) or the compound of Formula (II), (Ila), or (lie), when m is 2 or 3 then the radicals R4 are identical or different, preferably different; and R4 is positioned on carbon atoms 2 to 6 of the pyridine core of the Formula (I), (la), (lb) or (Ic). In another embodiment of the present disclosure, the process is carried out in a continuous reactor.

[0038] In an embodiment of the present disclosure, there is provided a process of obtaining a compound of Formula (I), (la), (lb) or (Ic) as disclosed herein, wherein the process results in the compound of Formula (I), (la), (lb) or (Ic) having more than or equal to 95% biogenic carbon, preferably more than or equal to 98%, more preferably more than or equal to 99 %, better more than or equal to 99.5% such as 100% biogenic carbon.

[0039] In an embodiment of the present disclosure, the compound of Formula (II), or (Ila) is a bio-based compound obtained from biomass derived sources. In another embodiment of the present disclosure, the compound of Formula (II) may beobtained from non-biomass derived sources or partially from biomass derived sources.

[0040] In an embodiment of the present disclosure, there is provided a process of obtaining a compound of Formula (I), (la), (lb) or (Ic) as disclosed herein, wherein the ammonium salt catalyst is selected from a) ammonium (hydroxy)(Ci-C6)alkyl carboxylate such as ammonium lactate, ammonium tartrate, ammonium citrate, or ammonium acetate, more preferably ammonium acetate, b) ammonium halide such as ammonium fluoride or ammonium chloride, c) ammonium (bi) sulphate, d) ammonium (Ci-C6)alkyl (bi)sulfate, e) ammonium nitrate, f) ammonium (dihydrogen) phosphate, g) ammonium (Ci-C6)alkyl phosphate, or combinations thereof. In a preferred embodiment, the ammonium salt catalyst is ammonium acetate.

[0041] In an embodiment of the present disclosure, there is provided a process of obtaining a compound of Formula (I), (la), (lb) or (Ic) as disclosed herein, wherein ammonia is aqueous ammonia added in an amount in a range of 1.5 to 3.5 mole per mole of the aldehyde (A), (B) and / or (C) or the compound of Formula (II), (Ila), or (lie). In another embodiment of the present disclosure, aqueous ammonia is added in an amount in a range of 2 to 3 mole per mole of the aldehyde (A), (B) and / or (C) or the compound of Formula (II), (Ila), or (lie). In yet another embodiment of the present disclosure, aqueous ammonia is added in an amount in a range of 2.25 to 2.75 mole per mole of the aldehyde (A), (B) and / or (C) or the compound of Formula (II), (Ila), or (lie). In some embodiments, acetic acid is used for catalysing the reaction of bio-based compound of Formula (II) with ammonia.

[0042] In an embodiment of the present disclosure, there is provided a process as disclosed herein, wherein the process is starting from the compound of Formula (II), (Ila), or (lie).

[0043] In an embodiment of the present disclosure, there is provided a process as disclosed herein, wherein the compound of Formula (II), or (Ila) has identical Ri, R2 and R3, linear or branched (Ci-C6)alkyl group, particularly compound of Formula (II) is selected from tri-2,4,6-(Ci-C4)alkyl-l,3,5-trioxane, preferably tri-2,4,6-(C1-C2) alkyl-1,3,5-trioxane, more preferably 2,4,6-trimethyl-l,3,5-trioxane.

[0044] In an embodiment of the present disclosure, there is provided a process as disclosed herein, wherein the compound of Formula (I), or (la) has 2 or 3 R4 groups, particularly 2 different R4 groups, more particularly, R4 groups are positioned on the carbon atoms 2 and 5 of the pyridine core, preferably, compound of Formula (I) is selected from 2-(Ci-C4)alkyl-5-(Ci-C4)alkylpyridine, preferably compound of Formula (I) is 2-(Ci-C2)alkyl-5-(Ci-C2)alkylpyridine and more preferably compound of Formula (I) is 2-methyl-5-ethylpyridine.

[0045] In an embodiment of the present disclosure, there is provided a process as disclosed herein, wherein the process results in a yield of at least 70% of the compound of Formula (I), (la), (lb) or (Ic) with respect to weight of the compound of Formula (II), (Ila), or (lie).

[0046] In an embodiment of the present disclosure, there is provided a process as disclosed herein, wherein the process results in the compound of Formula (I) having at least 95% purity.

[0047] In an embodiment of the present disclosure, there is provided a process as disclosed herein, wherein the process further comprises the step (iii) of oxidizing the compound of Formula (I), (la), (lb) or (Ic) with an oxidizing agent particularly permanganate such as potassium permanganate or nitric acid, preferably nitric acid, to produce pyridinecarboxylic acid especially pyridine-3 -carboxylic acid; wherein pyridinecarboxylic acid has particularly more than or equal to 95% biogenic carbon, more particularly more than or equal to 98%, more preferably more than or equal to 99%, better more than or equal to 99.5% such as 100% biogenic carbon. In another embodiment of the present disclosure, oxidizing the compound of Formula (I), (la), (lb), or (Ic) is carried out in the presence of nitric acid. In one another embodiment of the present disclosure, oxidizing the compound of Formula (I) is carried out in the presence of nitric acid.

[0048] In an embodiment of the present disclosure, there is provided a process as disclosed herein, wherein the compound of Formula (I), (la), (lb) or (Ic) and nitric acid are in a mole ratio range of 1: 1 to 1:15, preferably in a range of 1:6 to 1: 12.

[0049] In an embodiment of the present disclosure, there is provided a process as disclosed herein, the process comprising the steps of: (i) providing aldehyde (A),(B) and / or (C) or the compound of Formula (II), (Ila), or (lie), its optical isomers, and solvates thereof, derived from a plant-based bioethanol; (ii) reacting the aldehyde (A), (B) and / or (C) or compound of Formula (II), (Ila) or (lie), its optical isomers, and solvates thereof, with ammonia and an ammonium salt catalyst in a semi-continuous or continuous reactor; (iii) maintaining the reactor at a pressure in a range of 30-60 bar and a temperature in a range of 200-280°C during the reaction; (iv) producing bio-based compound of Formula (I), (la), (lb) or (Ic), its salts and solvates thereof; and (v) the step (iii) of oxidizing the compound of Formula (I), (la), (lb) or (Ic) with oxidizing agent particularly permanganate such as potassium permanganate or nitric acid, preferably nitric acid, to produce pyridinecarboxylic acid especially pyridine-3-carboxylic acid; wherein pyridinecarboxylic acid has particularly more than or equal to 95% biogenic carbon, more particularly more than or equal to 98 %, more preferably more than or equal to 99 %, better more than or equal to 99.5 % such as 100% biogenic carbon.

[0050] In an embodiment of the present disclosure, there is provided a process as disclosed herein, wherein the pyridine carboxylic acid especially pyridine-3-carboxylic acid is converted to pyridine carboxamide, preferably pyridine-3-carboxamide following the steps: (a) esterifying the pyridinecarboxylic acid especially pyridine- 3 -carboxylic acid with preferably a (Ci-C6)alkanol, preferably a (Ci-C4)alkanol such as ethanol, to obtain (Ci-C6)alkyl pyridinecarboxylate, especially (Ci-C4)alkyl pyridine-3 -carboxylate such as ethyl pyridine-3-carboxylate; and (b) aminolysis of the (Ci-C6)alkyl pyridinecarboxylate in presence of an amine source to obtain pyridine carboxamide preferably pyridine-3-carboxamide, wherein the pyridine carboxamide especially pyridine-3-carboxamide has more than or equal to 98%, more preferably more than or equal to 99%, and better more than or equal to 99.5%, such as 100% biogenic carbon.

[0051] In an embodiment of the present disclosure, there is provided a process as disclosed herein, wherein the esterifying step is carried out in presence of an acid; particularly the acid is a mineral acid such as sulfuric acid.

[0052] In an embodiment of the present disclosure, there is provided a process as disclosed herein, wherein the esterifying the pyridinecarboxylic acid especiallypyridine-3 -carboxylic acid with a (Ci-C6)alkanol, preferably a (Ci-C4)alkanol such as ethanol, butanol, isoamyl alcohol to obtain (Ci-C6)alkyl pyridinecarboxylate, especially (Ci-C4)alkyl pyridine-3 -carboxylate such as ethyl pyridine-3-carboxylate, butyl pyridine-3carboxylate or isoamyl pyridine-3-carboxylate; wherein ethanol is bioethanol.

[0053] In an embodiment of the present disclosure, there is provided a process as disclosed herein, wherein the amine source is selected from aqueous ammonia, gaseous ammonia, or its combination thereof.

[0054] In an embodiment of the present disclosure, there is provided a process as disclosed herein, wherein the pyridine carboxylic acid especially pyridine-3-carboxylic acid is converted to pyridine carboxamide, preferably pyridine-3 -carboxamide following the steps: (a) esterifying the pyridinecarboxylic acid especially pyridine- 3 -carboxylic acid in presence of sulfuric acid with preferably a (Ci-C6)alkanol, preferably a (Ci-C4)alkanol such as ethanol, butanol, isoamyl alcohol to obtain (Ci-C6)alkyl pyridinecarboxylate, especially (Ci-C4)alkyl pyridine-3 -carboxylate such as ethyl pyridine-3 -carboxylate, butyl pyridine -3carboxylate or isoamyl pyridine-3 -carboxylate;; and (b) aminolysis of the (Ci-Ce)alkyl pyridinecarboxylate in presence of an amine source selected from aqueous ammonia, gaseous ammonia, or its combination thereof, to obtain pyridinecarboxamide preferably pyridine-3 -carboxamide, wherein pyridine carboxamide especially the pyridine-3 -carboxamide has more than or equal to 98%, more preferably more than or equal to 99%, better more than or equal to 99.5%, such as 100% biogenic carbon.

[0055] In an embodiment of the present disclosure, there is provided a process as disclosed herein, the process comprising the steps of: (i) providing aldehyde (A), (B) and / or (C) or the compound of Formula (II), (Ila), or (lie), its optical isomers, and solvates thereof, derived from a plant-based bioethanol; (ii) reacting the aldehyde (A), (B) and / or (C) or compound of Formula (II), (Ila) or (lie), its optical isomers, and solvates thereof, with ammonia and an ammonium salt catalyst in a semi-continuous or continuous reactor; (iii) maintaining the reactor at a pressure in a range of 30-60 bar and a temperature in a range of 200-280°C during the reaction;(iv) producing bio-based compound of Formula (I), (la), (lb) or (Ic) its salts and solvates thereof; (v) oxidizing the compound of Formula (I), (la), (lb) or (Ic) with oxidizing agent particularly permanganate such as potassium permanganate or nitric acid, preferably nitric acid, to produce pyridinecarboxylic acid especially pyridine-3 -carboxylic acid; and (vi) the pyridine carboxylic acid especially pyridine-3 -carboxylic acid is converted to pyridine carboxamide, preferably pyridine-3 -carboxamide following the steps: (a) esterifying the pyridinecarboxylic acid especially pyridine-3-carboxylic acid in presence of sulfuric acid with preferably a (Ci-C6)alkanol, preferably a (Ci-C4)alkanol such as ethanol, butanol, or isoamyl alcohol to obtain (Ci-C6)alkyl pyridinecarboxylate, especially (Ci-C4)alkyl pyridine-3-carboxylate such as ethyl pyridine- 3 -carboxylate; and (b) aminolysis of the (Ci-C6)alkyl pyridinecarboxylate in presence of an amine source selected from aqueous ammonia, gaseous ammonia, or its combination thereof, to obtain pyridine carboxamide preferably pyridine-3 -carboxamide, wherein the pyridine carboxamide especially the pyridine-3-carboxamide has more than or equal to 98%, more preferably more than or equal to 99%, better more than or equal to 99.5%, such as 100% biogenic carbon.

[0056] In an embodiment of the present invention, there is provided a process for producing pyridine carboxamide derivatives and preferably pyridine-3-carboxamide having more than or equal to 98%, more preferably more than or equal to 99%, better more than or equal to 99.5%, such as 100% biogenic carbon, the process according to Scheme-II comprising the steps of: (i) yielding alkylaldehyde particularly (Ci-C6)alkylaldehyde preferably acetaldehyde from a plant-based bio alcohol particularly bio (Ci-C6)alkanol such as bioethanol from sugarcane molasses, sugarcane juice or sugarcane syrup; (ii) converting the alkylaldehyde especially acetaldehyde to a compound of Formula (II); (iii) reacting the compound of Formula (II), its optical isomers, salts and solvates thereof, with ammonia and an ammonium salt catalyst to produce a compound of Formula (I), its optical isomers, salts and solvates thereof; (iv) oxidizing the compound of Formula (I), its optical isomers, salts and solvates thereof with nitric acid to produce pyridine carboxylic acid, its salts and solvates thereof, preferably pyridine-3 -carboxylic acidand its salts; (v) esterifying the pyridine carboxylic acid and its salts preferably pyridine-3 -carboxylic acid its salts and solvates thereof, to obtain (C1-C6)alkyl pyridinecarboxylate, particularly (C1-C6)alkyl pyridine-3-carboxylate preferably ethyl pyridine-3-carboxylate, butyl pyridine-3-carboxylate, or isoamyl pyridine-3-carboxylate and (vi) aminolysis of the (C1-C6)alkyl pyridinecarboxylate, particularly (C1-C6)alkyl pyridine-3-carboxylate preferably ethyl pyridine-3-carboxylate to obtain pyridine carboxamide especially pyridine-3-carboxamide,Scheme-IIwherein, n, m, q, R₁, R₂, R₃ and R₄ are as disclosed herein, preferably (C₁-C₄)alkyl such as methyl or ethyl, and R₅ represents a linear or branched (C₁-C₆)alkyl, more preferably (C₁-C₄)alkyl such as ethyl, and q represents m-1, preferably 1.

[0057] In an embodiment of the present invention, there is provided a process for producing pyridine carboxamide according to Scheme-Ill comprising the steps of: (i) yielding acetaldehyde from a plant-based bioethanol from sugarcane molasses, sugarcane juice or sugarcane syrup; (ii) converting the acetaldehyde to a compound of Formula (Ila); (iii) reacting the compound of Formula (Ila) with ammonia and an ammonium salt catalyst to produce a compound of Formula (la); (iv) oxidizing the compound of Formula (la) with nitric acid to produce pyridine carboxylic acid and its salts, preferably pyridine-3 -carboxylic acid and its salts; (v) esterifying the pyridine carboxylic acid and its salts preferably pyridine-3-carboxylic acid to obtain (Ci-Cejalkyl pyridinecarboxylate, particularly (Ci-C6)alkyl pyridine-3 -carboxylate preferably ethyl pyridine-3 -carboxylate, and (vi) aminolysis of the (Ci-C6)alkyl pyridinecarboxylate, particularly (Ci-C6)alkyl pyridine-3 -carboxylate preferably ethyl pyridine-3 -carboxylate to obtain pyridine carboxamide especially pyridine-3 -carboxamide,Scheme-Illwherein n, m, q, R4 and R5 are as defined herein before in Scheme -II.

[0058] In an embodiment of the present disclosure, there is provided a process according to Scheme-IV, the process comprising the steps of: (i) yielding acetaldehyde from a plant-based bioethanol from sugarcane molasses, sugarcane juice or sugarcane syrup; (ii) converting the acetaldehyde to a compound of Formula (Ila); (iii) reacting the compound of Formula (Ila) with ammonia and an ammonium salt catalyst to produce a compound of Formula (lb); (iv) oxidizing the compound of Formula (lb) with nitric acid to produce pyridine carboxylic acid and its salts, preferably pyridine- 3 -carboxylic acid and its salts; (v) esterifying the pyridine carboxylic acid and its salts preferably pyridine-3 -carboxylic acid to obtain (Ci-Cejalkyl pyridinecarboxylate, particularly (Ci-Cejalkyl pyridine-3 -carboxylate preferably ethyl pyridine-3-carboxylate, and (vi) aminolysis of the (Ci-Cejalkyl pyridinecarboxylate, particularly (Ci-Cejalkyl pyridine-3 -carboxylate preferably ethyl pyridine-3-carboxylate to obtain pyridine carboxamide especially pyridine-3-carboxamide,Scheme -IVwherein, n, R₄ and R₅ is as defined herein before in Scheme-II, preferably R₄ are different, and more preferably represents (C₁-C₄)alkyl such as methyl or ethyl.

[0059] In an embodiment of the present disclosure, there is provided a process according to Scheme-V comprising the steps of: (i) yielding acetaldehyde from a plant-based bioethanol from sugarcane molasses, sugarcane juice or sugarcane syrup; (ii) converting the acetaldehyde to a compound of Formula (lie); (iii) reacting the compound of Formula (lie) with ammonia and an ammonium salt catalyst to produce a compound of Formula (Ic); (iv) oxidizing the compound of Formula (Ic) with nitric acid to produce pyridine carboxylic acid and its salts, preferably pyridine-3 -carboxylic acid and its salts; (v) esterifying the pyridine carboxylic acid and its salts preferably pyridine-3-carboxylic acid to obtain (Ci-Ce)alkyl pyridinecarboxylate, particularly (Ci-Cejalkyl pyridine-3 -carboxylate preferably ethyl pyridine-3 -carboxylate, and (vi) aminolysis of the latter (Ci-Ce)alkyl pyridinecarboxylate, particularly (Ci-Cejalkyl pyridine-3 -carboxylate preferably ethyl pyridine-3-carboxylate, butyl pyridine-3 -carboxylate, or isoamyl pyridine-3 -carboxylate to obtain pyridine carboxamide especially pyridine-3-carboxamide,Scheme-V

[0060] wherein R4 and R5 is as defined herein before in Scheme-IV. In another embodiment of the present disclosure, bio ethanol is obtained from fermentation of plant-based raw materials, such as Saccharum officianum (sugarcane) molasses or from sugarcane syrup or juice; and the obtained bioethanol is oxidized to result in bio-based acetaldehyde. In a particular embodiment, sugarcane molasses, syrup or juice, is procured by Godavari Biorefineries Limited; and bioethanol is extracted. Subsequent conversions of bioethanol to bio-based acetaldehyde and further to biobased 2,4,6-trimethyl-l,3,5-trioxane is carried out by Godavari Biorefineries Limited.

[0061] In an embodiment of the present disclosure, there is provided a process for producing pyridine-3 -carboxamide having more than or equal to 98%, more preferably more than or equal to 99%, better more than or equal to 99.% such as 100% biogenic carbon, the process comprising the steps of: (i) yielding acetaldehyde from plant-based bioethanol from sugarcane molasses, sugarcane juice or sugarcane syrup; (ii) converting acetaldehyde to a compound of Formula (II), (Ila) or (lie), its optical isomers, salts and solvates thereof; (iii) reacting the compound of Formula (II), (Ila) or (lie) with ammonia and an ammonium salt catalyst to produce a compound of Formula (I), (I(Ia), (lb) or (Ic), its salts and solvates thereof; (iv) oxidizing the compound of Formula (I) with nitric acid to produce pyridine-3-carboxylic acid its salts and solvates thereof; (v) esterifying pyridine-3 -carboxylic acid to obtain ethyl pyridine-3 -carboxylate, and (vi)aminolysis of ethyl pyridine-3 -carboxylate to obtain pyridine-3-carboxamide, wherein n, and m, are as disclosed herein.

[0062] In an embodiment of the present disclosure, there is provided a process for producing pyridine-3 -carboxamide as disclosed herein, wherein the step (iii) is carried out at a pressure in a range of 30-60 bar and a temperature in a range of 200-280°C. In another embodiment of the present disclosure, the step (iii) is carried out at a pressure is in a range of 40-58 bar and a temperature is in a range of 220-270°C. In yet another embodiment of the present disclosure, the step (iii) is carried out at a pressure is in a range of 48-56 bar and a temperature in a range of 240-260°C.

[0063] In an embodiment of the present disclosure, there is provided a process for producing pyridine-3 -carboxamide having more than or equal to 98%, more preferably more than or equal to 99%, better more than or equal to 99.5% such as 100% biogenic carbon, the process comprising the steps of: (i) yielding acetaldehyde from plant-based bioethanol from sugarcane molasses, sugarcane juice or sugarcane syrup; (ii) converting the acetaldehyde to a compound of Formula (II), (Ila) or (lie); (iii) reacting the compound of Formula (II), (Ila) or (lie) with ammonia and an ammonium salt catalyst at a pressure in a range of 30-60 bar and a temperature in a range of 200-280°C to produce a compound of Formula (I), (la), (lb), or (Ic); (iv) oxidizing the compound of Formula (I), (la), (lb) or (Ic) with nitric acid to produce pyridine-3 -carboxylic acid; (v) esterifying the pyridine-3-carboxylic acid in the presence of an acid with ethanol to obtain ethyl pyridine-3-carboxylate, and (vi) aminolysis of ethyl pyridine-3 -carboxylate in the presence of an amine source selected from aqueous ammonia, gaseous ammonia, or its combination thereof, to obtain pyridine-3 -carboxamide, wherein n, m, q, Ri, R2, R3, R4 and Rs are as disclosed herein.

[0064] In an embodiment of the present disclosure, there is provided a process for producing pyridine-3 -carboxamide as disclosed herein, wherein the ammonium salt catalyst is selected from ammonium (hydroxy)(Ci-C6)alky carboxylate such as ammonium lactate, ammonium tartrate, ammonium citrate, or ammonium acetate, more preferably ammonium acetate, b) ammonium halide such as ammonium fluoride or ammonium chloride, c) ammonium (bi)sulphate, d) ammonium (Ci-C6)alkyl (bi)sulfate, e) ammonium nitrate, f) ammonium (dihydrogen) phosphate, g) ammonium (Ci-C6)alkyl phosphate, or combinations thereof, used in an amount in a range of 0.01 to 0.1 mole per mole of the compound of Formula (II). In a preferred embodiment of the present disclosure, the ammonium salt catalyst is ammonium acetate used in an amount in a range of 0.02 to 0.06 mole per mole of the compound of Formula (II).

[0065] In an embodiment of the present disclosure, there is provided a process for producing pyridine-3 -carboxamide as disclosed herein, wherein the step of oxidizing the compound of Formula (I), (la), (lb) or (Ic) with nitric acid is carried out in a continuous flow reactor preferably made of a corrosion-resistant alloy.

[0066] In an embodiment of the present disclosure, there is provided a process as disclosed herein, wherein the process further comprises scrubbing and recycling NOx gases generated during the oxidation of the compound of Formula (I), (la), (lb) or (Ic) to pyridine-3-carboxylic acid.

[0067] In an embodiment of the present disclosure, there is provided a process for producing pyridine-3 -carboxamide as disclosed herein, wherein the process is carried out in a reactor which is operated in a semi-continuous, or continuous mode. In another embodiment of the present disclosure, the process is carried out in continuous mode in a continuous flow reactor.

[0068] In an embodiment of the present disclosure, there is provided a process for producing pyridine-3 -carboxamide as disclosed herein, wherein the pyridine-3-carboxamide is purified by recrystallization or ion exchange.

[0069] In an embodiment of the present disclosure, there is provided a process for producing pyridine-3 -carboxamide having more than or equal to 98%, more preferably more than or equal to 99%, better more than or equal to 99.5%, such as 100% biogenic carbon, the process comprising the steps of: (i) yielding acetaldehyde from plant-based bioethanol from sugarcane molasses, sugarcane juice or sugarcane syrup; (ii) converting the acetaldehyde to a compound of Formula (II), (Ila) or (lie); (iii) reacting the compound of Formula (II), (Ila) or (lie) with ammonia and an ammonium salt catalyst to produce a compound of Formula (I), (la), (lb) or (Ic) wherein ammonium salt catalyst is ammonium acetate; (iv)oxidizing the compound of Formula (I), (la), (lb) or (Ic) with nitric acid in a continuous flow reactor preferably made of a corrosion-resistant alloy which is operated in a semi-continuous, or continuous mode to produce pyridine-3-carboxylic acid; (v) esterifying the pyridine-3-carboxylic acid to obtain ethyl pyridine-3 -carboxylate, and (vi) aminolysis of ethyl pyridine-3 -carboxylate to obtain pyridine-3-carboxamide, wherein n, m, q, Ri, R2, R3 and R4 are as disclosed herein and the pyridine-3 -carboxamide obtained is purified by recrystallization or ion exchange.

[0070] In an embodiment of the present disclosure, there is provided pyridine-3-carboxamide, its salts and solvates such as hydrates, having more than or equal to 98 %, more preferably more than or equal to 99 %, and better more than or equal to 99.5%, such as 100% biogenic carbon, wherein, the pyridine-3 -carboxamide is produced by the process as disclosed herein and has a purity of at least 98%; and the pyridine-3 -carboxamide has a C14 content of at least 98 percent modern carbon (pMC) as measured by accelerator mass spectrometry.

[0071] In an embodiment of the present disclosure, there is provided a pyridine carboxamide preferably pyridine-3-carboxamide, its salts and solvates such as hydrates as disclosed herein, wherein the pyridine carboxamide preferably pyridine-3 -carboxamide, its salts and solvates having more than or equal to 98%, more preferably more than or equal to 99%, better more than or equal to 99.5%, such as 100% biogenic carbon; and the pyridine-3 -carboxamide has a C14 content of at least 98 percent modem carbon (pMC) as measured by accelerator mass spectrometry.

[0072] In an embodiment of the present disclosure, there is provided compounds of Formula (II) especially 2,4,6- tri(Ci-C6)alkyl-l,3,5-trioxane, (Ila) or (lie), as defined herein, preferably 2,4,6-trimethyl-l,3,5-trioxane, having more than or equal to 98 %, more preferably more than or equal to 99 %, better more than or equal to 99.5 % such as 100% biogenic carbon; and the compounds of Formula (II) especially 2,4,6- tri(Ci-C6)alkyl-l,3,5-trioxane, (Ila) or (lie), as defined herein, preferably 2,4,6-trimethyl-l,3,5-trioxane has a C14 content of at least 98 percent modern carbon (pMC) as measured by accelerator mass spectrometry.

[0073] In an embodiment of the present disclosure, there is provided compounds of Formula (la) as defined herein with m is equal to 2 and R4 are different, especially 2-(Ci-C6)alkyl-5-(Ci-C6)alkylpyridine preferably 2-methyl-5-ethylpyridine, its salts and solvates such as hydrates, having more than or equal to 98 %, more preferably more than or equal to 99%, better more than or equal to 99.5% such as 100% biogenic carbon, wherein compounds of Formula (la) as defined herein with m is equal to 2 and R4 are different, especially 2-(Ci-C6)alkyl-5-(Ci-C6)alkylpyridine preferably 2-methyl-5-ethylpyridine is produced by the process as disclosed herein and has a purity of at least 98%; and the compounds of Formula (la) as defined herein with m is equal to 2 and R4 are different, especially 2-(Ci-C6)alkyl-5-(Ci-C6)alkylpyridine, preferably 2-methyl-5-ethylpyridine has a C14 content of at least 98 percent modem carbon (pMC) as measured by accelerator mass spectrometry.

[0074] In an embodiment of the present disclosure, there is provided 2-(C₁-C₆)alkyl-5-(C₁-C₆)alkylpyridine preferably 2-methyl-5-ethylpyridine, its salts and solvates thereof, having more than or equal to 98%, more preferably more than or equal to 99%, and better more than or equal to 99.5% such as 100% biogenic carbon; and the 2-(C₁-C₆)alkyl-5-(C₁-C₆)alkylpyridine preferably 2-methyl-5-ethylpyridine has a C14 content of at least 98 percent modern carbon (pMC) as measured by accelerator mass spectrometry.

[0075] In an embodiment of the present disclosure, there is provided pyridine carboxylic acid, its salts and solvates thereof, preferably pyridine-3-carboxylic acid, its salts and solvates such as hydrates, having more than or equal to 98%, more preferably more than or equal to 99%, better more than or equal to 99.5% such as 100% biogenic carbon; and the pyridine carboxylic acid its salts and solvates thereof, preferably pyridine- 3 -carboxylic acid has a C14 content of at least 98 percent modem carbon (pMC) as measured by accelerator mass spectrometry.

[0076] In an embodiment of the present disclosure, there is provided (Ci-C6)alkyl pyridine-3 -carboxylate, preferably ethyl pyridine-3 -carboxylate, its salts and solvates such as hydrates, having more than or equal to 98%, more preferably more than or equal to 99 %, better more than or equal to 99.5% such as 100% biogeniccarbon; and the (Ci-C6)alkyl pyridine-3-carboxylate, preferably ethyl pyridine-3-carboxylate has a C14 content of at least 98 percent modem carbon (pMC) as measured by accelerator mass spectrometry.

[0077] Although the subject matter has been described in considerable detail with reference to certain examples and implementations thereof, it is understood that other implementations are possible and included within the scope of the present invention.EXAMPLES

[0078] The invention will now be illustrated with working examples, which is intended to illustrate the working of invention and not intended to take restrictively to imply any limitations on the scope of the present invention. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood to one of ordinary skill in the art to which this invention belongs. Although methods and materials similar or equivalent to those described herein can be used in the practice of the disclosed methods and compositions, the exemplary methods, devices, and materials are described herein. It is to be understood that this invention is not limited to particular methods, and experimental conditions described, as such methods and conditions may apply. The present invention will be described in a more detailed manner by way of examples. However, these examples should not be construed as limiting the scope of the present invention.Example 1Process of obtaining biogenic 2-methyl-5-ethylpyridine (MEP)

[0079] The process for producing 2 -methyl- 5 -ethylpyridine with 100% biogenic carbon comprises the conversion of bio-based 2,4,6-trimethyl-l,3,5-trioxane to 2-methy 1- 5 -ethylpyridine.1.1. Synthesis of bio-based 2,4,6-trimethyl-l,3,5-trioxane

[0080] Bio-based 2,4,6-trimethyl-l,3,5-trioxane was obtained from bio-based acetaldehyde using the following process (Scheme-VI).CH32,4,6-trimethyl-1,3,5-trioxaneScheme-VI

[0081] Bioethanol was obtained from fermentation of plant-based raw materials, such as Saccharum officianum (sugarcane) molasses or from sugarcane syrup or juice; and the obtained bioethanol was oxidized to result in bio-based acetaldehyde. In particular, sugarcane molasses, were procured by Godavari Biorefineries Limited; and bioethanol was extracted from molasses. Subsequent conversions of bioethanol to bio-based acetaldehyde and further to bio-based 2,4,6-trimethyl- 1,3,5-trioxane were carried out by Godavari Biorefineries Limited.

[0082] The process of conversion of bio-based acetaldehyde to bio-based 2,4,6-trimethyl-l,3,5-trioxane is described herein. The acetaldehyde liquid feed stream thus obtained from bioethanol, was passed through a reactor column packed with heterogeneous resin catalyst (crosslinked polystyrene with sulphonic acid) bed at a controlled circulation rate of 3 m3 / h, with a catalyst temperature of about 15 to 20 °C. The weight ratio of acetaldehyde to catalyst was 5.74, and the catalyst throughput was 4.9 g / h / ml of catalyst. The pressure was maintained in a range of 0.5 to 1.5 kg / cm2throughout the reaction time of 1 hour. The process resulted in obtaining 99.5% pure bio-based 2,4,6-trimethyl-l,3,5-trioxane.1.2. Synthesis of MEP

[0083] Bio-based 2,4,6-trimethyl-l,3,5-trioxane was converted to 2-methyl-5-ethylpyridine using the following process and as per reaction scheme-VII. / 40-50 BarAmmonium Acetate""'CH H3C2,4,6-trimethyl-1,3,5- 2-methyl-5-ethylpyridinetrioxaneScheme- VII

[0084] A mixture of 25% aqueous ammonia solution, containing ammonium acetate in catalyst amount (3% by weight based upon the weight of 2,4,6-trimethyl-1,3,5-trioxane used), and 50 kg of 2,4,6-trimethyl-l,3,5-trioxane, was passed to the reaction system having volume of 0.490 Litre (Table 1), in a continuous reactor. The total residence time of the reaction mixture in the reactor was maintained about 30 minutes; pressure was 50-55 bar, and temperature was maintained at 250°C to obtain the reaction product. After cooling the reaction product, the organic or oily layer was separated from aqueous layer and dehydrated. The oily layer was distilled under reduced pressure, and the distillates evaporating between 175 and 180°C were collected.Table 1: Input raw material for the synthesis of MEPS. No. Raw material Quantity Molecular kg. moles Molar (kg) weight ratio 2,4,6-trimethyl- 50 132 0.378 1 11,3,5-trioxaneAqueous 64 17 0.941 2.5 2ammonia 25%Ammonium 1.50 77 0.02 0.0513acetate

[0085] The collected distillates were subjected to Gas Chromatography (GC) using the following parameters to determine the purity of the obtained 2,4,6-trimethyl-1,3,5-trioxane and MEP.

[0086] Oven Programme: 70°C–1min–10°C / min–100°C–0min–20°C / min–240°C-10min; Injector Temperature: 250 °C; Detector Temperature: 260 °C;Column: DB624 (30m-530pm-3pm); Injection Volume: 0.2 pL; Split Ratio: 50:1; Retention Time of MEP: 9.567 min; and Retention Time of 2,4,6-trimethyl-l,3,5-trioxane: 7.69 minutes.Result:

[0087] The reaction yielded 96% by weight of 2,4,6-trimethyl-l,3,5-trioxane with 99.5% purity, and the acetaldehyde conversion was 90% as confirmed by GC analysis. A 70% yield was achieved for 2-methyl-5-ethylpyridine with a purity of > 98.0%.Example 2Synthesis of pyridine-3-carboxylic acid

[0088] MEP obtained from Example 1 was converted to pyridine- 3 -carboxylic acid using the following process and as per reaction scheme- VIII.- NOx / - CO22-methyl-5-ethylpyridine pyridine-3-carboxylic acid Scheme- VIII

[0089] A mixture of 6.0 % MEP and 21.90 % nitric acid (HNO3, 60%) were passed through a 0.490 lit reactor tube made of Hast-alloy at a temperature of 240-250 °C at 55 atm. pressure. MEP and nitric acid were taken in a molar ratio of 1:7 (Table 2). The reaction retention time was 13.0 minutes, and the conversion took place in 35 minutes. The liquid reaction product weighed 340 kg and the remaining 60 kg (15 %) passed off as gas. The liquid reaction product was concentrated up to 75-80 %, was cooled to 5°C and about 22.5 kg of nicotinic acid hydronitrate with a pyridine-3 -carboxylic acid content of 65.0 % crystallized out. 85 kg of mother liquor was kept aside for recycling.

[0090] The obtained nicotinic acid hydronitrate was then dissolved in 70 kg of water and heated to 60° C temperature. The pH was adjusted to 3.3 by the addition of 15 kg of 2-methyl-5-ethyl pyridine and the solution was heated at 90°C. After cooling to 0°C temperature, the precipitated pyridine-3 -carboxylic acid was centrifuged off and dried. 90 kg of mother liquor was kept aside for recycling.

[0091] The obtained mother liquors were combined together and was adjusted to starting concentration (6%) by addition of 2-methyl-5-ethyl pyridine, 60% nitric acid and water. The above solution was passed again through a 0.490 lit Hast alloy reactor at 240- 250°C temperature and 55 bar. Through recycling of mother liquors, additional 10 % of pyridine-3 -carboxylic acid was obtained. The reaction also resulted in 60 kg of NOx and CO2and 300 kg of distilled water.Table 2: Input raw material for the synthesis of pyridine-3-carboxylic acid S. No. Raw material Quantity (kg) kg. moles % LoadingMEP 24 0.198 6160% nitric acid 146 1.390 21.902Water 230 72.103Total (kg) 400 100

[0092] The purity of pyridine-3-carboxylic acid was determined using HPLC with the following parameters.

[0093] Mobile Phase: Mobile Phase A- (40% MeCN + 59.95% H2O + 0.05% H2SO4) Mobile Phase B- (90% MeCN + 9.95 % + 0.05% H2SO4); Column Flow: Iml / min; Column Oven Temperature: 30°C; Detector: UV detector; Detection wavelength: 250 nm; Column: Primesep 100 Column Size: 150 x 4.6 Make: SIELC; Injection Volume:5pL; Retention Time (Min): Pyridine-3 -carboxylic acid: 4.77 min; 2,5 Pyridine dicarboxylic Acid (PDCA):2.1 min; 2-methyl-5-ethyl pyridine (MEP): 11.47 min; and Pyridine: 8.31 min.Results

[0094] 14.65 kg of pyridine-3-carboxylic acid was isolated having purity of 98% as determined by HPLC Analysis. Isolated yield of pyridine- 3 -carboxylic acid was 60.0% at a MEP conversion of 99%. 2.35 kg of pyridine- 3 -carboxylic acid was obtained after recycling of mother liquors. The total yield of pyridine- 3 -carboxylic acid was 70% with 99% of MEP conversion.Example 3Synthesis of Dyridine-3-carboxamide

[0095] Pyridine-3-carboxylic acid obtained from Example 2 was subjected to esterification, followed by aminolysis to obtain pyridine-3- carboxamide.3.1. Esterification of Pyridine- 3 -carboxylic acid

[0096] The esterification of pyridine-3 -carboxylic acid was carried out using the following process and reaction scheme-IX.apyridine-3-carboxylic acid ethyl pyridine-3-carboxylate Scheme-IX

[0097] 14.65 kg (0.119 moles) of pyridine-3-carboxylic acid and 107 kg (2.33 moles) of ethanol (solvent) were heated to reflux temperature in presence of 38 kg (0.38 moles) of concentrated H2SO4(acid) for 16 hrs. The reaction was monitored by thin layer chromatography (TLC). After complete conversion of pyridine-3-carboxylic acid, the reaction mixture was cooled, and neutralised with 38 kg (purity 25%, 0.53 moles) of aqueous ammonia. The precipitate containing ammonium sulphate was filtered off and the filtrate was subjected to distillation to remove ethanol-water mixture. Then ethyl pyridine-3-carboxylate was extracted using ethyl acetate. The reaction output also comprised ammonium sulphate, ethanol-water mixture, and residue. After recovery of ethyl acetate, ethyl pyridine-3 -carboxylate was isolated under vacuum and analysed using GC with the following parameters.

[0098] Oven Programme: 70°C–1min–10°C / min–100°C–0min–20°C / min–240°C-10min; Injector Temperature: 250 °C; Detector Temperature: 260 °C; Column: DB624 (30m-530pm-3pm); Injection Volume: 0.2 pL; Split Ratio: 50:1; Retention Time (Min) ethyl pyridine- 3 -carboxylate: 13.667 min and Pyridine: 6.93 min. Results

[0099] From the esterification reaction, 15.87 kg of ethyl pyridine-3 -carboxylate was isolated with 99% purity and 90% yield. The conversion of pyridine-3-carboxylic acid was 100%.3.2. Aminolysis of ethyl pyridine- 3 -carboxylate

[0100] Aminolysis of ethyl pyridine-3 -carboxylate was carried out using the following process and reaction scheme -X.F"'Xs"" fj" '^Yethyl pyridine-3-carboxylate pyridine-3-carboxamide Scheme-X

[0101] 15.87 kg (0.10 moles) of ethyl pyridine-3-carboxylate and 34.0 kg of aq. ammonia solution (0.5 moles, amine source) were taken in a stirred vessel, with purged ammonia gas (0.94 moles, amine source) and kept for 24 hours below 0°C (Table 4). The reaction was monitored and the conversion of ethyl pyridine-3-carboxylate was checked on TLC until completion of reaction. The reaction product was then filtered and the isolated pyridine-3-carboxamide was crystallized. Pyridine-3 -carboxamide in soluble form in aqueous mass was recovered by distillation. Ethanol was recovered completely from aqueous mass (54 kg of aqueous ammonia solution) and crude pyridine-3 -carboxamide was recrystallized using aqueous ammonia.

[0102] The obtained crude pyridine-3 -carboxamide was also subjected to purification using column chromatography which utilized an ion-exchange resinsuch as a weakly basic anion exchange resin and ethanol to obtain pure pyridine-3 -carboxamide.

[0103] The purity of the obtained pyridine-3 -carboxamide was determined using HPLC analysis with the following parameters. Mobile Phase: KH2PO42.72gm + H3PO43ml in IL Water; Column Flow: Iml / min; Column Oven Temperature: 40°C; Detector: PDA; Detection wavelength: 261 nm; Column: Inertsil ODS-3 (5pm, 4.6 X 250 mm); Injection Volume: lOpL; Retention Time (Min) pyridine-3 -carboxamide: 4.9 min; and pyridine-3 -carboxy lie acid: 5.527 min.

[0104] The isolated pyridine-3 -carboxamide was further analysed for its biogenic carbon content. The biogenic carbon content was obtained by measuring the ratio of radiocarbon in the material relative to a National Institute of Standards and Technology (NIST) modern reference standard (SRM 4990C). This ratio was calculated as a percentage and reported as percent modern carbon (pMC).

[0105] The value obtained relative to the NIST standard was normalized to the year 1950 AD so the % bio-based carbon content was calculated from pMC by applying a small adjustment factor for C 14 in carbon dioxide in air as on the day of determining the biogenic carbon content. Precision on the result was cited as + / -3% (absolute). The cited precision on the analytical measure (pMC) was 1 sigma (1 relative standard deviation). The reported result only applied to the analyzed material. The accuracy of the result relied on the measured carbon in the analyzed material having been in recent equilibrium with CO2in the air and / or from fossil carbon (more than 40,000 years old), such as petroleum or coal. The result only applied to relative carbon content, not to relative mass content. The result was calculated by adjusting pMC by the applicable " Atmospheric adjustment factor (REF)". The atmospheric adjustment factor was 100.00; = pMC / 1.000.Results

[0106] Aminolysis of ethyl pyridine-3 -carboxylate (100% conversion), resulted in 11.55 kg of pure pyridine-3 -carboxamide with 90% yield.

[0107] The pure pyridine-3-carboxamide had 100% bio-based carbon (as fraction of total organic carbon) with 100.23 + / - 0.28 pMC, indicating that thematerial was entirely sourced from plant sources. This in turn indicated that the compounds prepared according to the present invention, are biogenic compounds i.e., 2,4,6-trimethyl-l,3,5-trioxane, 2-methyl-5-ethylpyridine and pyridine-3-carboxylic acid also had 100% bio-based carbon. Further ethyl pyridine-3-carboxylate had 100% bio-based carbon as the reaction involved the use of bioethanol.Advantages of the present disclosure

[0108] The present invention discloses a process for producing biogenic 2-methyl- 5 -ethylpyridine (MEP). The process achieves a 70% yield of MEP with more than 98% purity. Additionally, the process involves the use of bio-based 2,4,6-trimethyl-l,3,5-trioxane. The present invention also discloses a process for producing pyridine-3-carboxamide having at least 95% of biogenic carbon via the synthesis of MEP having at least 98% of biogenic carbon. The process yields 90% pyridine-3-carboxamide, and further the produced pyridine- 3 -carboxamide has less than 100 ppm of pyridine-3 -carboxylic acid owing to the use of single step purification. Overall, both the disclosed processes of MEP and pyridine-3-carboxamide are less expensive owing to the use of bio-based starting materials and reduced use of undesirable chemicals.

Claims

1. I / We Claim:

1. A process of obtaining a compound of Formula (I), its salts and solvates thereof, the process comprising the steps of:3.a) providing aldehyde (A), (B) and / or (C) or a compound of Formula (II), its optical isomers, and solvates thereof, derived from a plant-based bioethanol; b) reacting the aldehyde (A), (B) and / or (C) or the compound of Formula (II), its optical isomers, and solvates thereof, with ammonia and an ammonium salt catalyst in a semi-continuous or continuous reactor;4.c) maintaining the reactor at a pressure in a range of 30-60 bar and a temperature in a range of 200-280°C during the reaction; and5.d) producing bio-based compound of Formula (I), its salts and solvates thereof,7.

8. (it;9.Scheme-I10.wherein, (A), (B) and (C) can be identical or different; preferably identical; Ri, R2, and R3 identical or different, preferably identical, are independently selected from linear or branched (Ci-C6)alkyl;11.R4 is selected from linear or branched (Ci-C6)alkyl;12.n is 1, 2 or 3; m is 1, 2 or 3;13.with the proviso that:14.the ammonium salt catalyst is added in an amount in a range of 0.01 to 0.1 mole per mole of the aldehyde (A), (B) and / or (C) or the compound of Formula (II);15.when m is 2 or 3 then the radicals R4 are identical or different, preferably different;16.R4 is positioned on one of the carbon atoms 2 to 6 of the pyridine core of the Formula (I); and the process is optionally conducted from (A), (B), and / or (C) directly by combining step i) and ii) without isolating the compound of Formula (II).

2. The process as claimed in claim 1, wherein the process results in the compound of Formula (I) having more than or equal to 95% biogenic carbon, preferably more than or equal to 98%, more preferably more than or equal to 99%, and better more than or equal to 99.5%, such as 100% biogenic carbon.

3. The process according to any one of the preceding claims, wherein the ammonium salt catalyst is selected from a) ammonium (hydroxy)(Ci-C6)alkyl carboxylate such as ammonium lactate, ammonium tartrate, ammonium citrate, or ammonium acetate, more preferably ammonium acetate, b) ammonium halide such as ammonium fluoride or ammonium chloride, c) ammonium (bi)sulphate, d) ammonium (Ci-C6)alkyl (bi)sulfate, e) ammonium nitrate, f) ammonium (dihydrogen) phosphate, g) ammonium (Ci-C6)alkyl phosphate, or combinations thereof.

4. The process according to any one of the preceding claims, wherein ammonia is aqueous ammonia added in an amount in a range of 1.5 to 3.5 mole per mole of the aldehyde (A), (B) and / or (C) or the compound of Formula (II).

5. The process according to any one of the preceding claims, wherein Ri, R2, R3 and R4 are independently selected from (Ci-C4)alkyl, preferably (Ci-C2)alkyl; n is 1 or 2, preferably 1; and m is 1 or 2, preferably 2.

6. The process according to any one of the preceding claims, wherein the process is starting from the compound of Formula (II).

7. The process according to any one of the preceding claims, wherein the compound of Formula (II) has identical Ri, R2 and R3, linear or branched (Ci-Ce) alkyl group, particularly the compound of Formula (II) is selected from tri-2,4,6-(Ci-C4alkyl)- 1,3,5-trioxane, preferably 2,4,6-trimethyl-l,3,5-trioxane.

8. The process according to any one of the preceding claims, wherein the compound of Formula (I) has 2 or 3 R4 groups, particularly 2 different R4 groups, more particularly R4 groups are positioned on the carbon atoms 2 and 5 of the pyridine core, preferably the compound of Formula (I) is selected from 2-(Ci-C4)alkyl-5- (Ci-C4)alkylpyridine, preferably is 2-methyl-5-ethylpyridine.

9. The process according to any one of the preceding claims, wherein the process further comprises the step of oxidizing the compound of Formula I with an oxidizing agent particularly permanganate such as potassium permanganate or nitric acid, preferably nitric acid, to produce pyridinecarboxylic acid especially pyridine- 3 -carboxylic acid; wherein pyridinecarboxylic acid has particularly more than or equal to 95 % biogenic carbon, more particularly more than or equal to 98%, more preferably more than or equal to 99%, and better more than or equal to 99.5%, such as 100% biogenic carbon.

10. The process as claimed in claim 9, wherein the pyridinecarboxylic acid especially pyridine- 3 -carboxylic acid is converted to pyridine carboxamide, preferably pyridine-3-carboxamide, following the steps of:25.a. esterifying the pyridinecarboxylic acid especially pyridine-3-carboxylic acid with a (Ci-C6)alkanol, preferably a (Ci-C4)alkanol such as ethanol, to obtain (Ci- Cejalkyl pyridinecarboxylate, especially (Ci-C4)alkyl pyridine-3 -carboxylate such as ethyl pyridine-3-carboxylate; and26.b. aminolysis of the (Ci-C6)alkyl pyridinecarboxylate in presence of an amine source to obtain pyridine carboxamide preferably pyridine-3-carboxamide, wherein the pyridine carboxamide especially pyridine-3 -carboxamide has more than or equal to 98%, more preferably more than or equal to 99%, and better more than or equal to 99.5%, such as 100% biogenic carbon.

11. The process as claimed in claim 10, wherein the esterifying step is carried out in presence of an acid; particularly the acid is a mineral acid, such as sulfuric acid.

12. The process as claimed in claim 10, wherein the amine source is selected from aqueous ammonia, gaseous ammonia, or its combination thereof.

13. A process for producing pyridine carboxamide derivatives and preferably pyridine- 3 -carboxamide having more than or equal to 98%, more preferably more than or equal to 99%, and better more than or equal to 99.5%, such as 100% biogenic carbon, the process according to Scheme-II, particularly according to Scheme-Ill, more particularly according to Scheme-IV, preferably according to scheme V, comprising the steps of:i. yielding alkylaldehyde particularly (Ci-C6)alkylaldehyde preferably acetaldehyde from a plant-based particularly bio (Ci-C6)alkanol such as bioethanol from sugarcane molasses, sugarcane juice or sugarcane syrup; ii. converting alkylaldehyde preferably acetaldehyde to a compound of Formula (II), (Ila), or (lie), its optical isomers, salts and solvates thereof; iii. reacting the compound of Formula (II), (Ila), or (lie), its optical isomers, salts and solvates thereof, with ammonia and an ammonium salt catalyst to produce a compound of Formula (I), (la), (lb) or (Ic), its salts and solvates thereof;30.iv. oxidizing the compound of Formula (I), (la), (lb) or (Ic), its salts and solvates thereof with nitric acid to produce pyridine carboxylic acid and its salts, preferably pyridine-3 -carboxylic acid, its salts and solvates thereof; and31.v. esterifying the pyridine carboxylic acid and its salts preferably pyridine-3- carboxylic acid, its salts and solvates thereof, to obtain (Ci-Cejalkyl pyridinecarboxylate preferably (Ci-Cejalkyl pyridine-3 -carboxylate preferably ethyl pyridine-3-carboxylate, and32.vi. aminolysis of the (Ci-Cejalkyl pyridinecarboxylate, particularly (Ci- Ce)alkyl pyridine-3-carboxylate preferably ethyl pyridine-3 -carboxylate to obtain pyridine-3 -carboxamide, wherein n, m, Ri, R2, R3 and R4 are as defined in any one of the claims 1 or 2, preferably (C1-C4) alkyl such as methyl or ethyl, and R5 represents a linear or branched (Ci-Cejalkyl, more preferably (Ci-C4)alkyl such as ethyl, and q represents m-1 preferably 1; Scheme-II33.Scheme-Ill34.

35. Scheme-IV37.

14. The process as claimed in claim 13, wherein the step (iii) is carried out at a pressure in a range of 30-60 bar and a temperature in a range of 200-280°C.

15. The process according to any one of claims 13 to 14, wherein the ammonium salt catalyst is selected from ammonium (hydroxy)(Ci-C6)alkyl carboxylate such as ammonium lactate, ammonium tartrate, ammonium citrate, or ammonium acetate, more preferably ammonium acetate, b) ammonium halide such as ammoniumfluoride or ammonium chloride, c) ammonium (bi) sulphate, d) ammonium (Ci- C6)alkyl (bi)sulfate, e) ammonium nitrate, f) ammonium (dihydrogen) phosphate, g) ammonium (Ci-C6)alkyl phosphate, or combinations thereof, used in an amount in a range of 0.01 to 0.1 mole per mole of the compound of Formula (II), (Ila), or (lie).

16. The process according to any one of claims 13 to 15, wherein the step (iv) of oxidizing the compound of Formula (I), (la), (lb) or (Ic) with nitric acid is carried out in a continuous flow reactor preferably made of a corrosion-resistant alloy.

17. The process according to any one of claims 13 to 16, further comprising scrubbing and recycling NOx gases generated during the oxidation of the compound of Formula (I), (la), (lb), or (Ic) to pyridine-3-carboxylic acid.

18. The process according to any one of claims 13 to 17, wherein the process is carried out in a reactor which is operated in a semi-continuous, or continuous mode.

19. The process according to any one of claims 13 to 18, wherein the pyridine-3- carboxamide is purified by recrystallization or ion exchange.

20. Pyridine carboxamide preferably pyridine-3-carboxamide, its salts and solvates thereof, having more than or equal to 98%, more preferably more than or equal to 99%, better more than or equal to 99.5 % such as 100% biogenic carbon, wherein: the pyridine carboxamide preferably pyridine-3 -carboxamide is produced by the process as claimed in any one of the preceding claims and has a purity of at least 98%; and44.the pyridine carboxamide preferably pyridine-3 -carboxamide has a C14 content of at least 98 percent modern carbon (pMC) as measured by accelerator mass spectrometry.

21. Pyridine carboxamide its salts and solvates thereof, preferably pyridine-3- carboxamide, its salts and solvates thereof, having more than or equal to 98%, more preferably more than or equal to 99%, and better more than or equal to 99.5% such as 100% biogenic carbon; and the pyridine-3 -carboxamide has a C14 content of at least 98 percent modern carbon (pMC) as measured by accelerator mass spectrometry.

22. Compounds of Formula (II), its optical isomers and salts thereof, especially 2,4,6- tri(Ci-C6)alkyl-l,3,5-trioxane, (Ila) or (lie) as defined herein in claim 13, preferably 2,4,6-trimethyl-l,3,5-trioxane, having more than or equal to 98%, more preferably more than or equal to 99%, and better more than or equal to 99.5 % such as 100% biogenic carbon; and the 2,4,6- tri(Ci-C6)alkyl-l,3,5-trioxane preferably 2,4,6-trimethyl-l,3,5-trioxane has a C14 content of at least 98 percent modem carbon (pMC) as measured by accelerator mass spectrometry.

23. 2-(Ci-C6)alkyl-5-(Ci-C6)alkylpyridine its salts and solvates thereof, preferably 2- methyl-5-ethylpyridine, its salts and solvates thereof, having more than or equal to 98%, more preferably more than or equal to 99%, and better more than or equal to 99.5% such as 100% biogenic carbon, wherein:47.the 2-(Ci-C6)alkyl-5-(Ci-C6)alkylpyridine preferably 2-methyl-5-ethylpyridine is produced by the process as claimed in any one of the preceding claims and has a purity of at least 98%; and48.the 2-(Ci-C6)alkyl-5-(Ci-C6)alkylpyridine preferably 2-methyl-5-ethylpyridine has a C14 content of at least 98 percent modern carbon (pMC) as measured by accelerator mass spectrometry.

24. 2-(Ci-C6)alkyl-5-(Ci-C6)alkylpyridine preferably 2-methyl-5-ethylpyridine, its salts and solvates thereof, having more than or equal to 98%, more preferably more than or equal to 99%, and better more than or equal to 99.5% such as 100% biogenic carbon; and the 2-(Ci-C6)alkyl-5-(Ci-C6)alkylpyridine preferably 2- methyl-5-ethylpyridine has a C14 content of at least 98 percent modern carbon (pMC) as measured by accelerator mass spectrometry.

25. Pyridine carboxylic acid, its salts and solvates thereof, preferably pyridine-3- carboxylic acid, its salts and solvates thereof, having more than or equal to 98%, more preferably more than or equal to 99%, and better more than or equal to 99.5% such as 100% biogenic carbon; and the pyridine carboxylic acid, its salts and solvates thereof, preferably pyridine-3 -carboxylic acid its salts and solvates thereof, has a C14 content of at least 98 percent modern carbon (pMC) as measured by accelerator mass spectrometry.

26. (Ci-C6)alkyl pyridine-3-carboxylate preferably ethyl pyridine-3 -carboxylate, its salts and solvates, having more than or equal to 98%, more preferably more than or equal to 99%, and better more than or equal to 99.5% such as 100% biogenic carbon; and the (Ci-C6)alkyl pyridine-3-carboxylate preferably ethyl pyridine-3- carboxylate has a C14 content of at least 98 percent modern carbon (pMC) as measured by accelerator mass spectrometry.

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