DESC:FIELD OF THE INVENTION
The present application provides the novel process for the preparation of Bempedoic acid or its pharmaceutically acceptable salts in substantially pure form and high yield suitable for commercial scale.

BACKGROUND OF THE INVENTION
Bempedoic acid, a novel therapeutic approach for low-density lipoprotein cholesterol (LDL-C) lowering, inhibits adenosine triphosphate citrate lyase (ACL), an enzyme involved in fatty acid and cholesterol synthesis. Bempedoic acid (NEXLITOL) and Bempedoic acid combination with Ezitimibe (NEXLIZET) were approved by USFDA on 20 February 2020 and 26 February 2020 respectively.
Bempedoic acid having the chemical name of 8-Hydroxy-2,2,14,14-tetramethyl pentadecanedioic acid and representing by the below mentioned structure of formula (I):

Formula (I)
Bempedoic acid and its process for the preparation the same was first disclosed in US7335799 by Esperion Therapeutics. The schematic representation of the disclosed process was mentioned below.

The process disclosed in the ‘799 patent is having lot of drawbacks like obtaining low yields with respective to intermediates and final compounds. The above-mentioned process involves the excessive usage of (4.3 Equivalents) sodium borohydride (NaBH4) in the keto reduction step corresponding to starting material. The formation of below mentioned impurity was observed when 1, 5 dibromo pentane was reacted with ethyl isobutyrate in presence of strong base like LDA.

Bempedoic acid obtained in low yield of 60%, purity having 83% and the nature of the compound is in viscous oily form. The viscous oil nature and low purity Bempedoic acid is not a suitable material for pharmaceutical formulation.
The publication WO2020194152 A1 discloses a process for the preparation of Bempedoic acid which discloses the usage of Sodium borohydride (NaBH4) in higher equivalents (2.8 Equivalents) in the keto reduction step with respective to starting material.
The publication WO2020257571 A1discloses the below process for the preparation of Bempedoic acid. The process involves an additional step which requires a further conversion of chloro to iodo substrate using metal iodides (Step 2).

The process involves additional purification methods which involves the usage of large quantities of silica gel and solvent exchanges to get pure form of Bempedoic Acid.
Therefore, still there is need for the development of commercially viable, cost-effective process for the preparation of purest form of Bempedoic acid, which will be suitable for pharmaceutical formulation.

SUMMARY OF THE INVENTION
The present invention provides a novel process for the preparation Bempedoic acid or its pharmaceutically acceptable salts of formula I, which is cost effective and suitable for industrial production.
In an aspect the present application provides a process for preparation of Bempedoic acid of formula I

Formula I
which comprises
a) reacting 1-bromo-5-chloropentane of formula II

Formula II
with ethyl isobutyrate in presence of a base and in a suitable solvent to form ethyl 7-chloro-2,2-dimethylheptanoate of formula III

Formula III
b) reacting compound of formula III with p-toluene sulfonyl methyl isocyanide (TosMIC) in presence of a base, a phase transfer catalyst and in suitable solvent to form compound of formula IV

Formula IV
c) reacting compound of formula IV with an acid and in suitable solvent to form a Keto ester compound of formula V

Formula V
d) reacting keto ester compound of formula V with an ester hydrolysing agent in a suitable solvent to form keto acid compound of formula VI

Formula VI
e) reacting keto acid compound of formula IV with keto reducing agent in presence of base and in a suitable solvent to form Bempedoic acid compound of formula I
f) optionally purifying the Bempedoic acid of formula I in a suitable solvent.
In another aspect the present invention provides, crystalline form of bempedoic
acid characterized by powder X-ray diffraction pattern shown in the Figure 1.
In another aspect, the present invention provides crystalline form of bempedoic
acid characterized by its PXRD pattern having one or more peaks at 5.10, 10.28, 15.45, 17.27, 17.54, 17.90, 18.23, 18.69, 19.53, 20.35, 20.67, 21.82, 22.55 and 27.55 ± 0.2 degrees 2?.

BRIEF DESCRIPTION OF THE DRAWINGS
Figure 1 is the characteristic powder X-ray diffraction (XRD) pattern of bempedoic
acid obtained as per the present invention.

DETAILED DESCRIPTION OF THE INVENTION
In one embodiment the present invention particularly describes process for the preparation of Bempedoic acid of formula I

Formula I
In one embodiment the following scheme- 1 describe the process for the preparation of Bempedoic Acid of Formula I.

Scheme-1
In one embodiment step (a) of the present process involves, reacting 1-bromo-5-chloropentane of formula II with ethyl isobutyrate in presence of base in a suitable solvent to provide ethyl 7-chloro-2,2-dimethylheptanoate of formula III; wherein the suitable base is selected from Li metal/Diisopropyl amine, Li metal/Liq ammonia in presence of electron transfer reagents like isoprene or styrene, lithium diisopropyl amide, sodium hexamethyldisilazide, lithium hexamethyldisilazide; and in suitable solvent is selected from ethers or hydrocarbons or mixtures thereof; preferably the ether solvents are tetrahydrofuran, methyl tertiary butyl ether or mixture of both;
In another embodiment step (b) of the present process involves, reacting compound ethyl 7-chloro-2,2-dimethylheptanoate of formula III with p-toluene sulfonyl methyl isocyanide (TosMIC) in presence of base and a phase transfer catalyst in a suitable solvent to form a compound of formula IV, where in the base is selected from sodium hydride, potassium hydride, sodium amide, lithium amide sodium methoxide, potassium methoxide, sodium t-butoxide; most preferable base is sodium hydride; the phase transfer catalyst used herein is selected form tetrabutylammonium iodide, tetrabutylammonium bromide, benzyltriethylammonium chloride, methyltricaprylammonium chloride, methyltributylammonium chloride, and methyltrioctylammonium chloride, hexadecyltributylphosphonium bromide; preferably the phase transfer catalyst is tetrabutylammonium iodide; and the solvent is selected from ethers, ketones, amides, hydrocabons, sulphoxides or combination thereof; and preferable solvents are dimethyl sulphoxide, toluene or mixtures thereof
In another embodiment the product of the step (b) compound of formula IV proceeds to next step without any further purification.
In another embodiment step (C) of the present process involves, reacting compound of formula IV with an acid in a suitable solvent to form diethyl 2,2,14,14-tetramethyl-8-oxopentadecanedioate a compound of formula V; wherein the suitable acid is hydrochloric acid, sulphuric acid or acetic acid and suitable solvent is etheric solvents like diethyl ether, di isopropyl ether, methyl tertiary butyl ether, or hydrocarbon solvents like hexane or cyclohexane. The most preferable solvent is methyl tertiary butyl ether, and the corresponding most preferable acid is hydrochloric acid.
In another embodiment step (d) of the present process involves, reacting a keto ester of compound of formula V with suitable ester hydrolysing reagent in presence of a suitable protic solvent gives a keto acid of compound of formula VI; wherein the suitable ester hydrolysing agent is sodium hydroxide, potassium hydroxide, lithium hydroxide or calcium hydroxide; wherein the suitable solvent tetrahydrofuran, MTBE, dioxane, and dimethoxy ethane; alcohols, such as methanol, ethanol, ethylene glycol, 1-propanol, 2-propanol, 2-methoxyethanol, 1 -butanol, 2-butanol, iso-butyl alcohol, t-butyl alcohol and glycerol. The most preferable solvent is ethanol, and the corresponding most preferable base is sodium hydroxide.
In another embodiment step (d) of the present process involves the removing of impurities like unreacted keto ester of compound of formula IV or partially converted mono keto ester (14-(ethoxycarbonyl)-2,2,14-trimethyl-8-oxopentadecanoic acid); wherein after completion of reaction, the reaction mass was dissolved in water and ethylacetate wash was given.
In another embodiment Step (e) of the present process involves, reacting keto acid of compound of formula VI with a suitable keto reducing agent in presence of suitable solvent gives Bempedoic acid of compound of formula I; wherein the suitable keto reducing agent is Sodium borohydride, Sodium cyano borohydride, sodium triacetoxy boro hydride, potassium borohydride; and the suitable base is sodium hydroxide, potassium hydroxide, lithium hydroxide or calcium hydroxide ; and the suitable solvent is methanol, ethanol, and isopropanol. The most preferable keto reducing agent is Sodium borohydride; preferable base is sodium hydroxide, and the most preferable solvent is ethanol or isopropanol.
In another embodiment Bempedoic acid of formula I is optionally purified by using a suitable solvent; wherein the suitable solvent is selected form diethyl ether, methyl tertiary butyl ether, acetone, cyclohexane, ethyl acetate, acetonitrile, ethanol, methanol, heaxane, water or mixtures thereof. The most preferable solvent is acetone and hexane.
In another embodiment, the present invention provides crystalline form of bempedoicacid characterized by powder X-ray diffraction pattern shown in the Figure 1.
In another embodiment, the present invention provides crystalline form of bempedoic
acid characterized by its PXRD pattern having one or more peaks at 5.10, 10.28, 15.45, 17.27, 17.54, 17.90, 18.23, 18.69, 19.53, 20.35, 20.67, 21.82, 22.55 and 27.55 ± 0.2 degrees 2?.
In another embodiment the present invention provides method of crystallizing bempedoic acid from a suitable solvent selected from acetone, ethyl acetate, hexane, acetonitrile, or mixtures thereof.
In another embodiment the below are the abbreviations are used in the specification.
THF-Tetrahydrofuran, MTBE-Methyl tertiary butyl ether, g- Grams, mL-milliliters, °C- degrees centigrade, Eq-Equivalent, GC-Gas chromatography, HCl-Hydrochloric acid, Na2SO4-Sodium Sulphate, DMSO-Dimethyl Sulphoxide, Mg2SO4-Magnesium Sulphate, TLC-Thin layer Chromatography, HPLC-High performance Liquid Chromatography, PXRD- Powder X-ray Diffraction,

EXAMPLES
Example 1
Preparation of ethyl 7-chloro-2,2-dimethylheptanoate:

Method 1:
Under nitrogen atmosphere charged THF (10 mL) and MTBE (300 mL) into flask then added Diisopropylamine (67.0 g,1.2 eq) and Lithium metal (4.3 g, 1.15 eq) into reaction mass at 30-35°C. Raise the reaction mass temperature up to 40-50°C. Add isoprene (33.6 g) in THF solution into the reaction mass. stir the reaction mass up to clear solution at same temperature. The reaction mass was cooled to (-)30°C to (-)20°C under nitrogen atmosphere. After stirring for 10 minutes, Ethyl isobutyrate (78.3 g,1.25 eq) was added over period of 10 minutes, maintaining the temperature at -20 to -25° C. At the end of the addition, a brown, slightly hazy solution was formed, the mixture was stirred for 15 minutes, at -20 to -25° C. Bromochloropentane (100 g, 1 eq) was added by maintaining temperature at -20 to -25° C, to give clear light brown solution. After stirring for 10 hours at 0 to -5°C, the solution was warmed to 20° C forms viscous dark brown solution. The reaction mixture was quenched with pre-cooled (1° C.) 14% HCl over a period of 20 minutes, keeping the temperature below 15° C. The final pH was 1.0. The reaction mixture was then allowed to settle, and the organic layer was separated dried over Na2SO4 and concentrated under vacuum yields 112 g of Ethyl 7-chloro-2,2-dimethylheptanoate. Purity; GC: 96.2%.
Method 2:
Under nitrogen atmosphere charged THF (5 mL) and MTBE (300 mL) into flask then added Liquid Ammonia (200 mL) and Lithium metal (4.9 g, 1.3eq) into reaction mass at (-)50 to (-) 55°C. Slowly isoprene was added (33.6 g) into the reaction mass at below (-)55°C. The reaction mass was stirred at the same temperature until the brown colour solution was formed. After stirring for 10 minutes, Ethyl isobutyrate (78.3 g, 1.25eq) was added over period of 10 minutes, maintaining the temperature at -50 to -55° C. After the completion of the addition, the mixture was stirred for 15 minutes, maintaining the temperature at -35 to -40° C. At the end of the addition a brown, slightly hazy solution was formed. Bromochloropentane (100 g) was added by maintaining temperature at -35 to -40° C, to form clear light brown solution. After stirring for 10 hours at 0 to -5° C, the solution was warmed to 20° C gives a viscous dark brown solution. The reaction mixture was quenched with pre-cooled (1° C.) 14% HCl over a period of 20 minutes, keeping the temperature below 15° C. The final pH was 1.0. The reaction mixture was then allowed to settle, the organic layer was separated dried over Na2SO4 and concentrated under vacuum yields 110 g of Ethyl 7-chloro-2,2-dimethylheptanoate. Purity by GC: 95.2%
Method 3:
Charged THF (100 mL) into flask then added Diisopropylamine (82 g,1.5 eq) and cool to (-)50-(-)55°C then butyl lithium (300 mL) in hexanes was added into reaction mass at (-)50-(-)55°C. Raise the reaction mass temperature up to (-)30-(-)40°C. After stirring for 10 minutes, Ethyl isobutyrate (78.3 g,1.25 eq) was added over period of 10 minutes, maintaining the temperature at -20 to -25° C. At the end of the addition, the mixture was stirred for 15 minutes, maintaining the temperature at -20 to -25° C, slightly hazy solution was formed. Bromochloropentane (100 g) was added by maintaining temperature at -20 to -25° C to give clear light brown solution. After stirring for 10 hours at 0 to -5° C., the reaction mass temperature was raised to 20° C. The reaction mixture was quenched with pre-cooled (1° C.) 14% HCl over 20 minutes, keeping the temperature below 15° C. The final pH was 1.0. The reaction mixture was then allowed to settle, and organic layer was separated dried over Na2SO4 and concentrated under vacuum yields 118gm of Ethyl 7-chlorom-2,2-dimethylheptanoate. Purity by GC: 97.3%.
Example 2
Preparation of 2,2,14,14-tetramethyl-8-oxo-pentadecanedioic acid diethyl ester

Method 1:
Under Nitrogen atmosphere, to a solution of Ethyl -7-chloro-2,2- dimethylheptanoic acid ethyl ester (100 g, 1.0 eq), Tetra butylammonium iodide (17.0 g, 0.17) and p- Toluenesulfonyl methyl isocyanide (49.0 g, 0.55eq) in anhydrous DMSO (300 mL) was added sodium hydride (41.0 g, 2.2 eq) as lot wise at 10 – 15°C. The reaction mixture was stirred at room temperature for 2 h and quenched with ice-water (300 mL). The product was extracted with MTBE (300 mL). The organic layer was washed with water (200 mL) and separated, and the organic layer was cool to 10-15°C. To the organic layer concentrated hydrochloric acid (20 mL) was added and the mixture was stirred at room temperature for 1h. The solution was diluted with water (400 mL) and the aqueous layer was extracted with MTBE (200 mL). The combined organic layers were washed with saturated Sodium hydroxide solution (2 x 150 mL) and washed with brine (2 x 100 mL), the organic layer was separated dried over Na2SO4 and concentrated under vacuum gives 2,2,14,14-tetramethyl-8-oxo-pentadecanedioic acid diethyl ester (55.0 g).
Method 2:
Under Nitrogen atmosphere, to a solution of Ethyl -7-chloro-2,2- dimethylheptanoic acid ethyl ester (100 g,1.0 eq), Tetra butylammonium iodide (17.0 g, 0.17 eq) and p- Toluenesulfonyl methyl isocyanide (49.0 g, 0.55eq) in anhydrous DMSO (100 mL) and toluene (100 mL)was added into the reaction mass then add sodium hydride (41.0 g, 2.2 eq) as lot wise at 10 – 15oC. The reaction mixture was stirred at room temperature for 2.0 h and quenched with ice-water (300 mL). The product was extracted with Toluene (300 mL). The combined organic layers were washed with water (200 mL) and cool to 10-15°C. To the organic layer was added concentrated hydrochloric acid (20.0 mL) and the mixture was stirred at room temperature for 1h. The solution was diluted with water (400 mL) and the aqueous layer was extracted with Toluene (200 mL). The combined organic layers were washed with saturated sodium hydroxide solution (2 x 150 mL) and brine (2 x 100 mL), the organic layer was separated dried over Na2SO4 and concentrated under vacuum to give diethyl 8-isocyano-2,2,14,14-tetramethyl-8-toluenesulfonylpentadecanedioate (55.0 g).
Example 3
Preparation of 2,2,14,14-tetramethyl-8-oxopentadecanedioic acid

A solution of Sodium hydroxide (50 g) in water (100 mL) was added to a solution of 2,2,14,14-tetramethyl-8-oxo-pentadecanedioic acid diethyl ester (25 g) in ethanol (100 mL), the reaction mixture was heated to reflux until it completes. After completion of the reaction distil the solvent under vacuum and charged with water (200 mL). The aqueous solution was washed with ethyl acetate (20 mL) and the organic layer was separated. The aqueous layer was acidified to pH 2 with concentrated hydrochloric acid (100 mL) and extracted with MTBE (2 x 50 mL). The combined organic layers were dried over Mg2SO4 and concentrated under vacuum to give the crude product. The crude material was crystallized from ethyl acetate to give 2,2,14,14-tetramethyl-8-oxopentadecanedioic acid (19.1 g, 90 %) as white crystals. Purity: 99.0%.
Example 4
Preparation of 8-hydroxy-2,2,14,14-tetramethylpentadecanedioic acid

Method 1:
2,14,14-tetramethyl-8-oxopentadecanedioic acid (20 g, 0.05 mol) and ethanol (200 mL) were added at room temperature into a 500 mL flask fitted with a magnetic stir bar and nitrogen inlet. Water (10 mL) was added into the reaction flask and the reaction mass was cooled below 10°C. Sodium borohydride (0.7 g, 0.3 eq) and Sodium hydroxide solution was added portion wise to the reaction mass at 10°C. The temperature was allowed to rise to 27 °C and the reaction mass was stirred for 2 h. The progress of the reaction was monitored by TLC. After completion of the reaction, water (100 mL) was added to the reaction mass which was then extracted with MTBE (100 mL). The combined organic layer was washed with brine solution (2X50 ml) and dried over Na2SO4. The organic layer was evaporated under reduced pressure below 45 °C to obtain crude product. The crude product was dissolved in ethyl acetate and water mixture solution and isolated as white crystals yield (80%) Purity by HPLC: 99.7%.
Method 2:
2,14,14-tetramethyl-8-oxopentadecanedioic acid (20 g, 0.05mol) and isopropylaclohol (200 mL) were added at room temperature into a 500 mL flask fitted with a magnetic stir bar and nitrogen inlet. Water (10 mL) and sodium hydroxide (6.0 g, 3.0eq) was added into the reaction flask and the reaction mass temperature raise to 75-80°C and then maintain for 20 hrs. Percentage of the starting material was monitored by HPLC. Then added Sodium borohydride (0.45 g, 0.2 eq) charge into the reaction mass was stirred for 2 h at same temperature. The progress of the reaction was monitored by HPLC. After completion of the reaction, water (100 mL) was added to the reaction mass which was then extracted with MTBE (100 ml). The combined organic layer was washed with brine solution (2X50 ml) and dried over sodium sulfate. The obtained organic layer was evaporated under reduced pressure below 45 °C to obtain crude product. The crude product was dissolved in ethyl acetate and water mixture solution and isolated as white crystals yield (82%) Purity by HPLC:99.8%.
Reaction condition Percentage of Product formed
Isopropyl alcohol, NaOH, 75-80°C,
20 hrs HPLC data shows 21 % of starting material has been converted to product, 82% of starting material was present.
NaBH4 was added maintained at same temperature for 2 hrs. Completely converted to Product Bempedoic acid
Method 3:
2,14,14-tetramethyl-8-oxopentadecanedioic acid (20 g,0.05mol) and isopropylaclohol (200 mL) were added at room temperature into a 500 mL flask fitted with a magnetic stir bar and nitrogen inlet. Water (10 mL) and sodium hydroxide (6.0 g, 3.0 eq) was added into the reaction flask and the reaction mass temperature raise to 75-80°C and then maintain for 20 hrs. Then added Sodium borohydride (0.45 g, 0.2 eq) charge into the reaction mass was stirred for 2 h at same temperature. The progress of the reaction was monitored by TLC. After completion of the reaction, water (100 mL) was added to the reaction mass which was then extracted with MTBE (100 mL). The combined organic layer was washed with brine solution (2X50 mL) and dried over sodium sulfate. The obtained organic layer was evaporated under reduced pressure below 45 °C to obtain crude product. The crude product was dissolved in Acetone (20 mL) and added Hexanes (60.0 mL) mixture solution and isolated as white crystals yield (81%) Purity by HPLC: 99.6%.

,CLAIMS:1. A process for the preparation of Bempedoic acid compound of formula I

Formula I
which comprises
a) reacting 1-bromo-5-chloropentane of formula II

Formula II
with ethyl isobutyrate in presence of a base in a suitable solvent to provide 7- ethyl 7-chloro-2,2-dimethylheptanoate of formula III;

Formula III
b) reacting the compound of formula III with p-toluene sulfonyl methyl isocyanide in presence of a base and a phase transfer catalyst and in a suitable solvent to provide compound of formula IV;

Formula IV
c) reacting the compound of formula IV with a suitable acid in a suitable solvent to provide keto ester compound of formula V;

Formula V
d) hydrolyzing the keto ester compound of formula V with a suitable base in a suitable solvent to provide the keto acid compound of formula VI;

Formula VI
e) reducing the keto acid compound of formula VI with a suitable reducing agent in presence of a base in a suitable solvent to provide bempedoic acid of formula I.
f) optionally purifying the Bempedoic acid of formula I in a suitable solvent.
2. The process as claimed in Claim 1, wherein, in step (a) the base is Li/Diisopropylamine, Li/Liq. Ammonia in presence of electron transfer reagents, lithium diisopropyl amide, sodium hexamethyldisilazide, lithium hexamethyldisilazide; and the solvent is selected from ethers, aliphatic hydrocarbons or mixtures thereof; wherein the electron transfer reagents are styrene or isoprene and the suitable solvent is MTBE or THF or mixtures thereof; in step (b) the suitable base is sodium hydride and the phase transfer catalyst is tetrabutylammonium iodide; the suitable solvent is dimethyl sulphoxide, toluene or methyl tertiary butyl ether; in step (c) the suitable acid is hydrochloric acid and the suitable solvent is MTBE; in step (d) the suitable ester hydrolysing agent is sodium hydroxide, potassium hydroxide, lithium hydroxide or calcium hydroxide; and the suitable solvent is ethanol; in step (e) the suitable keto reducing agent is Sodium borohydride, Sodium cyano borohydride, sodium triacetoxy boro hydride, potassium borohydride; base is sodium hydroxide, potassium hydroxide, lithium hydroxide or calcium hydroxide and the suitable solvent is methanol, ethanol, and isopropanol.
3. The process as claimed in claim 1, wherein the compound of formula IV is not isolated.
4. A process for the preparation of compound of formula III,

Formula III
which comprises reacting 1-bromo-5-chloropentane of formula II with ethyl isobutyrate in presence of base an electron transfer reagent and suitable solvent; wherein the base is selected from Li metal/Diisopropylamine, Li metal/Liq ammonia and the electron transfer reagent is isoprene or styrene and suitable the solvent is MTBE or THF or mixtures thereof.
5. A process for the preparation of compound of formula IV,

Formula IV
wherein reacting compound ethyl 7-chloro-2,2-dimethylheptanoate of formula III with p-toluene sulfonyl methyl isocyanide (TosMIC) base is selected from sodium hydride, potassium hydride, sodium amide, lithium amide sodium methoxide, potassium methoxide, sodium t-butoxide; most preferable base is sodium hydride; the phase transfer catalyst used herein is selected form tetrabutylammonium iodide, tetrabutylammonium bromide, benzyltriethylammonium chloride, methyltricaprylammonium chloride, methyltributylammonium chloride, and methyltrioctylammonium chloride, hexadecyltributylphosphonium bromide; preferably the phase transfer catalyst is tetrabutylammonium iodide; and the solvent is selected from ethers, ketones, amides, hydrocabons, sulphoxides or combination thereof; and preferable solvents are dimethyl sulphoxide or toluene or mixtures thereof.
6. The process as claimed claim 5, the preferable base is sodium hydride, phase transfer catalyst is tetrabutylammonium iodide and the preferable solvent is DMSO and toluene or mixtures thereof.
7. A process for the preparation of bempedoic acid compound of formula I

Formula I
which comprises reducing the keto compound of formula VI with a suitable keto reducing agent and in presence of a suitable base and solvent.
8. The process as claimed claim 7, where in the suitable keto reducing agent is Sodium borohydride, Sodium cyano borohydride, sodium triacetoxy boro hydride, potassium borohydride; and the base is sodium hydroxide, potassium hydroxide, lithium hydroxide or calcium hydroxide; the suitable solvent is methanol, ethanol, or isopropylalcohol.
9. The process as claimed in claim 8, most preferable keto reducing agent is sodium borohydride, preferable base is sodium hydroxide, and the most preferable solvent is isopropylalcohol.
10. The process as claimed claim 9, the mole of ratio of compound of formula VI to the keto reducing agent is 1: < 0.25.
11. A process for the purification of bempedoic acid compound of formula I, which comprise of crystallizing bempedoic acid from a suitable solvent selected from acetone, ethyl acetate, hexane, acetonitrile, or mixtures thereof.
12. The process as claimed in claim 11, preferable solvent is acetone or hexane or mixtures thereof.