A process for the preparation of BIS[2-(perfluorohexyl) ethyl]phosphate or salts thereof

Abstract

The present invention relates to one pot process for preparation of salts of bis[2- (perfluorohexyl)ethyl]phosphate or its solution comprising, reacting perfluorohexyl ethyl alcohol with phosphoryl chloride in the presence of organic base in first solvent to obtain bis[2-(perfluorohexyl)ethyl]phosphorochloridate, which is hydrolyzed with water to give bis[2-(perfluorohexyl)ethyl] hydrogenphosphate, further the reaction mass is treated with base in second solvent to obtain desired product with high yield, which is not only cost-effective but also industrially scalable.

Description

[0001] A PROCESS FOR THE PREPARATION OF BIS[2-(PERFLUOROHEXYL) ETHYLJPHOSPHATE OR SALTS THEREOF FIELD OF THE INVENTION:

[0002] [1] The present invention relates to an improved process for the preparation of bis[2-(perfluorohexyl)ethyl]phosphate or salts thereof. More particularly, the present invention relates to one pot process for the preparation of sodium salt of bis[2-(perfluorohexyl)ethyl]phosphate or its solutions with higher yield, cost-effective and industrially scalable.

[0003] BACKGROUND OF THE INVENTION:

[0004] [2] Bis[2-(perfluorohexyl)ethyl] phosphate or salts thereof is having a chemical structure of formula (I) or formula (Is) as given below:

[0005] O o

[0006]

[0007] Formula (I) Formula (Is)

[0008] [3] Bis[2-(perfluorohexyl)ethyl] phosphate or salts thereof commonly used as surfactant in the paint industries. Commonly, fluoroalkyl phosphate surfactants and surface treatment agents contain multiple fluorochemical chains, containing a higher percentage of fluorine at a given concentration and are typically used because they are thought to provide better performance. However, the fluorinated starting materials are more expensive and have limited supply. Reduction of the amount of the fluorinated starting material in these surfactants while maintaining the same or better performance is desirable. Minimizing the process norms needed would not only reduce the cost, but also shorten the cycle time as fewer steps are needed in the production of the surfactants and less energy is required. Reducing the fluorine content would reduce the cost, but it is necessary to maintain product performance. Various process for preparation of fluoroalkyl phosphate surfactants are known in the prior arts.

[0009] [4] U.S. Patent number 3083224 (herein after US ‘224) firstly discloses mixed fluoroalkyl phosphates having the formula [CmF2m+i . CnH2n. 0]yP0(0M)3-ywhere m is 4 to 12, n is 1 to 16, and y is averaged to be 1.0 to 2.5. US ‘224 discloses their use in imparting oil repellency to textile materials, paper and similar articles, and also as dispersing agents, particularly when y is 2.

[0010] [5] Further, US ‘224 also discloses process for preparation of fluoroalkylphosphates by either phosphorus pentoxide or phosphorus oxychloride are reacted with the fluoroalcohols in presence of organic aromatic solvents such as benzene, toluene or xylene and pyridine as a base to obtain mixtures of the mono- and bis(perfluoroalkyl)phosphoric acids. Neutralization, using common bases such as ammonium or sodium hydroxides provides the corresponding phosphates. Reacting an excess of fluoroalcohol with phosphorus pentoxide followed by neutralization provides an equimolar mixture of mono(perfluoroalkyl)phosphate and bis(perfluoroalkyl)phosphate. The major drawback of this process is yield of obtained final product is very low i.e., less than 50%. Therefore, process for preparation of fluoroalkylphosphates as disclosed in US ‘229 is not suitable for large scale industrial production.

[0011] [6] Fluoroalkyl phosphate surfactants having ammonium as a counter ion as disclosed in US ‘224 can potentially release ammonia into the environment. Alternate counter ions need to be able to provide a stable surfactant, while also providing no adverse effects to the surfactant performance.

[0012] [7] U.S. Patent number 6684525 (herein after US ‘525) discloses process for preparation of sodium salt of bis-[2-(perfluorohexyl)ethyl]phosphate comprising reacting lH,lH,2H,2H-perfluorooctanol with phosphorous oxychloride in presence of anhydrous diethyl ether and triethylamine as base to obtain corresponding triethylamine hydrochloride salt. Resulting salt was dissolved in acetonitrile and water followed by layer separation. Obtained lower layer was isolated and dried under rotary evaporation to get mass as a viscous orange oil. Further, obtained viscous orange oil treated with ethanol and sodium hydroxide followed by isolation to obtain sodium salt of bis-[2-(perfluoro-hexyl)ethyl]phosphate having 53% yield. The major drawback of this process is yield of obtained sodium salt of bis-[2-(perfhrorohexyl)ethyl]phosphate is very low i.e.

[0013] 53% yield and require longer reaction time i.e. 12 to 24 hours. Therefore, process for preparation of sodium salt of bis-[2-( perfluorohexyl)ethyl]phosphate as disclosed in US ‘525 is not cost effective and not suitable for large scale industrial production. [8] U.S. Patent number 6271289 (herein after US ‘289) discloses process for preparation of (F(CF2)nCH2CH2O)2P(O)(O’NH4+) by reacting F(CF2CF2)2-8CH2CH2OH with phosphorus oxychloride in the presence of toluene at 115 °C, further water was added. The obtained hydrogen phosphate derivative was neutralized with ammonium hydroxide to give the mixture of monoalkyl ammonium phosphate, dialkyl ammonium phosphate and trialkyl phosphate derivatives. The drawback of this process is yield of obtained product has very low i.e 34.63 % and require high reaction temperature. Therefore, process for preparation of (F(CF2)nCH2CH2O)2P(O)(O“NH4+) as disclosed in US ‘289 is not suitable for large scale industrial production.

[0014] [9] Japanese patent number 6204779 (herein after JP ‘779) discloses process for preparation of perfluoroalkyl group containing phosphoric acid monoester comprising reacting perfluorohexylethyl alcohol with phosphorus pentoxide in the presence of phosphoric acid and fluorine-containing solvent such as 1,1, 1,2, 2, 3, 3, 4, 4, 5, 5,6,6-tri decafluorooctane, l,l,l,2,2,3,3,4,4-nonafluoro-4-ethoxybutane, m-xylene hexafluoride at 50 °C to 60 °C for 24 hours. Further, solvent was removed from the reaction mixture and ethyl acetate and water were added to dissolve the mixture followed by solvent and water removal from the reaction mixture to obtain product contain 93.5% of perfluoroalkyl group-containing phosphoric monoester, 4.6% of perfluoroalkyl group-containing phosphoric diester, and 1.9% of phosphoric acid. The drawback of this process is corrosive properties of phosphoric acid at high temperature and require longer reaction time i.e. 24 hours, which is not suitable for large scale industrial production.

[0015]

[0010] Therefore, still there exist need in the prior art to develop improved, economically viable and environment friendly process for manufacturing of bis[2-(perfluorohexyl)ethyl] phosphate or salts thereof having high yield, which may overcome drawbacks of the prior-art.

[0016] OBJECT OF THE INVENTION:

[0017]

[0011] The main obj ective of the present invention is to provide an improved process for the preparation of salts of bis[2-(perfluorohexyl)ethyl]phosphate or its solution with a higher yield and quality, which is simple, eco-friendly, and commercially viable.

[0018]

[0012] Another objective of the present invention is to provide a one pot process for preparation of bis[2-(perfluorohexyl)ethyl]phosphate or salts thereof with higher yield.

[0019] SUMMARY OF THE INVENTION:

[0020]

[0013] An aspect of the present invention provides an improved process for the preparation of salts of bis[2-(perfluorohexyl)ethyl]phosphate or its solution with a higher yield, purity and industrial advantages.

[0021]

[0014] Another aspect of the present invention particularly provides a one pot process for preparation of salts of bis[2-(perfluorohexyl)ethyl]phosphate or its solution comprising, reacting perfluoroalkyl ethyl alcohol compound of formula (II) with phosphoryl chloride compound of formula (III) in the presence of organic base in first solvent to obtain bis[2-(perfluorohexyl)ethyl]phosphorochloridate compound of formula (IV), optionally isolation of formula (IV) and hydrolyzed with water to give bis[2-(perfluorohexyl)ethyl] hydrogenphosphate compound of formula (I), further the pH of reaction mass is adjusted with base in second solvent to obtain desired product in high yield, which is not only cost-effective but also industrially scalable and it can be summarized in following schematic representation:

[0022] C6F13X^X\OHII Organic Base + Cl— P— Cl I First Solvent

[0023]

[0024] Cl Formula (II) Formula (III) Formula (IV)

[0025] First Solvent .Salt Base OH C6F13 p C6F Second Solvent13

[0026]

[0027] o Formula (Is) Formula (I) Scheme 1: Synthesis of salts of bis[2-(perfluorohexyl)ethyl] phosphate.

[0028] DETAILED DESCRIPTION OF THE INVENTION:

[0029]

[0015] The present invention provides an improved process for the preparation of a solution comprising bis[2-(perfluorohexyl)ethyl]phosphate compound of formula (I) or salts thereof.

[0030]

[0016] The invention will now be described in detail in connection with certain preferred embodiments, so that various aspects thereof may be fully understood and appreciated.

[0031]

[0017] While the following specification concludes with claims particularly pointing out and distinctly claiming the invention, it is anticipated that the invention can be more readily understood through reading the following detailed description and by studying the included examples.

[0032]

[0018] In one embodiment of the present invention, the process for the preparation of bis[2-(perfluorohexyl)ethyl]phosphate compound of formula (I) or salts (Is) thereof,

[0033] OH OH

[0034] I ^O. ,Ck I .0.

[0035] C6F13' ■C6F13 C6F13' p

[0036] II II ■C6F13

[0037] .Salt o o

[0038]

[0039] Formula (I) Formula (Is) comprising the steps of:

[0040] a. reacting perfluorohexyl ethyl alcohol compound of formula (II) with phosphoryl chloride compound of formula (III) in the presence of organic base in first solvent to obtain bis[2-(perfluorohexyl)ethyl]phosphorochloridate compound of formula (IV);

[0041] Organic Base " — ^OH + ci— P-Cl I First Solvent

[0042]

[0043] Cl Formula (II) Formula (III) Formula (IV)

[0044] b. hydrolyzing the step (a) bis[2-(perfluorohexyl)ethyl]phosphorochloridate compound of formula (IV) in the presence of water and first solvent to obtain bis[2-(perfluorohexyl)ethyl] hydrogenphosphate compound of formula (I);

[0045] Water OH X). I XX First Solvent QF13 C6Fn

[0046]

[0047] O Formula (IV) Formula (I)

[0048] c. optionally, treating bis[2-(perfluorohexyl)ethyl] hydrogenphosphate compound of formula (I) with base in second solvent to obtain salt of bis[2- (perfluorohexyl)ethyl] phosphate compound of formula (Is).

[0049] OH OH

[0050] ^O. | ,OXBase I ^o. P 'C6F13- ►C6F13* p' C6F13

[0051]

[0052] II Second Solvent II o o .Salt Formula (I) Formula (Is) wherein the step a) and b) or a) to c) are performed in one pot process.

[0053]

[0019] In another embodiment of the present invention, the process for preparation of a solution comprising bis[2-(perfluorohexyl)ethyl]phosphate compound of formula (I) or salts (Is) thereof,

[0054] .Salt O O

[0055] Formula (I) Formula (Is)

[0056]

[0057] comprising the steps of:

[0058] reacting perfluorohexyl ethyl alcohol compound of formula (II) with phosphoryl chloride compound of formula (III) in the presence of organic base in first solvent to obtain bis[2- (perfluorohexyl)ethyl]phosphorochloridate compound of formula (IV);

[0059] o Cl

[0060] ZXii Organic Base

[0061]

[0062] " — OH + ci— P-Cl I First Solvent Cl

[0063]

[0064] o

[0065] Formula (II) Formula (III) Formula (IV) hydrolyzing the step (a) bis[2-(perfluorohexyl)ethyl]phosphorochloridate compound of formula (IV) in the presence of water and first solvent to obtain bis[2-(perfluorohexyl)ethyl] hydrogenphosphate compound of formula (I);

[0066] ci Water OH First Solvent P C6F13

[0067]

[0068] o o Formula (IV) Formula (I) treating bis[2-(perfluorohexyl)ethyl]hydrogenphosphate compound of formula (I) with base in second solvent to obtain salts of bis[2-(perfluorohexyl)ethyl] phosphate compound of formula (Is) solution; and

[0069] OH

[0070] Base Second Solvent o ° .Salt

[0071]

[0072] Formula (I) Formula (Is) wherein the step a) and b) or a) to c) are performed in one pot process.

[0073]

[0020] The best methods and materials of performing step (a), step (b) & step (c) are any embodiment of the present invention are described here.

[0074]

[0021] In step (a), the condensation reaction using starting material perfluorohexyl ethyl alcohol and / or phosphoryl chloride can be prepared by process known in the prior-art or it was available in commercial scale. In present invention, the (perfluorohexyl)ethyl alcohol used for the reaction is in excess with that of phosphoryl chloride.

[0075]

[0022] In step (a), the organic base can be selected from pyridine, 4-dimethylaminopyridine (DMAP), N-methyl imidazole, tri ethyl amine, 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU), l,5-diazabicyclo[4.3. 0]non-5-ene (DBN) or mixture(s) thereof. Preferably, the base used is triethyl amine.

[0076]

[0023] In step (a), the base can be used in the ratio 1.0 to 3.0 mole equivalent to that of phosphoryl chloride; preferably the ratio is 1: 2; more preferably the molar ratio is 1: 2.05.

[0077]

[0024] In step (a), the condensation reaction can be carried out at temperature of -20 °C to 20 °C; preferably at -10 °C to 10 °C and more preferably at -5 °C to 5 °C.

[0078]

[0025] In step (a), the condensation reaction can be carried out for 3 to 30 hours; preferably for 3 to 10 hours and more preferably for 3 to 8 hours.

[0079]

[0026] In step (a), the condensation reaction can be carried out in presence of first solvent. The first solvent is selected from methyl tertiary butyl ether (MTBE) or a mixture of MTBE and organic solvent or cyclopentyl methyl ether (CPME) or a mixture of cyclopentyl methyl ether (CPME) and organic solvent. The organic solvent is selected from ethers such as diethyl ether, tetrahydrofuran; hydrocarbon solvents such as toluene, dichloromethane, ethylene dichloride, xylenes, mesyteline, open or closed crown ethers such as monoglyme, diglyme or mixture(s) thereof. Preferably, the condensation reaction is carried out in presence of methyl tertiary butyl ether.

[0080]

[0027] In still another embodiment of the present invention, distillation of MTBE for its recovery and reuse.

[0081]

[0028] In still another embodiment of the present invention, after completion of condensation reaction water can be used as washing solvent for removal of triethyl amine hydrochloride from the step (a) reaction mass. Further triethyl amine was recovered from aqueous mother liquor containing triethylamine hydrochloride salt.

[0082]

[0029] In still another embodiment of the present invention, step (b) hydrolysis reaction can be performed with or without isolation of step (a) of bis[2-(perfluorohexyl)ethyl] phosphorochloridate of compound of formula (IV).

[0083]

[0030] In step (b), the hydrolysis reaction can be carried out at temperature of -20 °C to 20 °C; preferably at -10 °C to 10 °C and more preferably at -5 °C to 5 °C.

[0084]

[0031] In step (b), the hydrolysis reaction can be carried out for 1 to 10 hours; preferably for 1 to 6 hours and more preferably for 1 to 4 hours.

[0085]

[0032] In step (b), the hydrolysis reaction can be carried out in presence of first solvent as defined above.

[0086]

[0033] In still another embodiment of the present invention, step (c) salt formation reaction can be performed with or without isolation of step (b) of bis[2-(perfluorohexyl)ethyl] hydrogenphosphate compound of formula (I).

[0087]

[0034] In step (c), the salt formation reaction can be carried out at temperature of -20 °C to 30 °C; preferably at 10 °C to 30 °C and more preferably at 25 °C to 30 °C.

[0088]

[0035] In step (c), the salt formation reaction can be carried out for 1 to 10 hours; preferably for 1 to 5 hours and more preferably for 1 to 3 hours.

[0089]

[0036] In step (c), the salt formation reaction can be carried out in presence of second solvent. The second solvent is selected from polar protic solvents such as Ci to Cio alcohol, water or mixture(s) thereof. Preferably in presence of isopropanol and water.

[0090]

[0037] In step (c), the base can be selected from ammonia, sodium hydroxide, butyl amine or tetramethyl ammonium hydroxide. The bases are not limiting to use for the pH adjustment the range of 7 to 10.

[0091]

[0038] In still another embodiment of the present invention, if required the solution of compound of formula (Is) can be stirred with 0.001 to 0.1 w / w of charcoal in presence or absence of filter aid to improve its color and filter the same to remove any other colored impurity present in it.

[0092]

[0039] In still another embodiment of the present invention, the process can be recycling aqueous layer, solvents and reagents for further batches and circumscribed the waste generation.

[0093]

[0040] In still another embodiment of the present invention, using selective solvent systems as above mentioned in step (a) and step (b) i.e. first solvent, surprisingly which impact on reducing the formation of process impurities and resulting higher yield of the product. Specifically, the process impurities are mono[2-(perfluorohexyl)ethyl] phosphorodichloridate (mono impurity) and tris[2-(perfluorohexyl)ethyl]phosphate (Tris impurity) formation(s) are controlled respectively in the ranging between 1 to 3 % and 2 to 5%.

[0094] ci

[0095] | .ci

[0096] C6FB P

[0097]

[0098] o

[0099] Mono[2-(perfluorohexyl)ethyl]phosphorodichloridate

[0100] ^C6F13

[0101]

[0102] o

[0103] Tris[2-(perfluorohexyl)ethyl]phosphate

[0104]

[0041] In still another embodiment of the present invention, the yield of obtained bis[2-(perfluorohexyl)ethyl]phosphate compound of formula (I) or salts (Is) thereof may have greater than 86 % w / w.

[0105]

[0042] In still another embodiment of the present invention, the surface tension value of obtained solution comprising salts of bis[2-(perfluorohexyl)ethyl]phosphate compound of formula (Is) in the range of 15 mN / m2to 18 mN / m2.

[0106]

[0043] In still another embodiment of the present invention, the specific gravity of obtained solution comprising salts of bis[2-(perfluorohexyl)ethyl]phosphate compound of formula (Is) in the range of 1.0 to 1.1.

[0107]

[0044] The present invention particularly provides an improved process for preparation of sodium salt of bis[2-(perfluorohexyl)ethyl] phosphate compound of formula (la), Na

[0108] O

[0109]

[0110] O

[0111] Formula (la)

[0112] comprising the steps of:

[0113] a. reacting perfluorohexyl ethyl alcohol compound of formula (II) with phosphoryl chloride compound of formula (III) in the presence of triethyl amine in MTBE to obtain bis[2-(perfluorohexyl)ethyl]phosphorochloridate compound of formula (IV);

[0114] O TEA

[0115] X~X"'X0H II + Cl— p— Cl I MTBE

[0116]

[0117] Cl Formula (II) Formula (III) Formula (TV)

[0118] b. hydrolyzing the step (a) bis[2-(perfluorohexyl)ethyl]phosphorochloridate compound of formula (IV) in the presence of water and MTBE to obtain bis[2- (perfluorohexyl)ethyl] phosphate compound of formula (I); and

[0119] ci Water OH MTBE C6F CeFi3

[0120]

[0121] o O Formula (IV) Formula (I)

[0122] c. treating bis[2-(perfluorohexyl)ethyl]hydrogenphosphate compound of formula (I) with sodium hydroxide in isopropyl alcohol to obtain sodium salt of bis[2- (perfluorohexyl)ethyl] phosphate compound of formula (la);

[0123] OH

[0124] NaOH Isopropanol

[0125]

[0126] o Formula (I) Formula (la) wherein the step (a) and (b) or (a) to (c) are performed in one pot process.

[0127]

[0045] In step (a), the triethylamine base can be used in the ratio 1.0 to 3.0 mole equivalent to that of phosphoryl chloride; preferably the ratio is 1 : 2; more preferably the molar ratio is 1: 2.05.

[0128]

[0046] In step (a), the condensation reaction can be carried out at temperature of -20 °C to 20 °C; preferably at -10 °C to 10 °C and more preferably at -5 °C to 5 °C.

[0129]

[0047] In step (a), the condensation reaction can be carried out for 3 to 30 hours; preferably for 3 to 10 hours and more preferably for 3 to 8 hours.

[0130]

[0048] In still another embodiment of the present invention, distillation of MTBE for its recovery and reuse.

[0131]

[0049] In still another embodiment of the present invention, after completion of condensation reaction water can be used as washing solvent for removal of triethyl amine hydrochloride from the step (a) reaction mass. Further tri ethyl amine was recovered from aqueous mother liquor containing triethylamine hydrochloride salt.

[0132]

[0050] In still another embodiment of the present invention, step (b) hydrolysis reaction can be performed with or without isolation of step (a) of bis[2-(perfluorohexyl)ethyl] phosphorochloridate of compound of formula (IV).

[0133]

[0051] In step (b), the hydrolysis reaction can be carried out at temperature of -20 °C to 20 °C; preferably at -10 °C to 10 °C and more preferably at -5 °C to 5 °C.

[0134]

[0052] In step (b), the hydrolysis reaction can be carried out for 1 to 10 hours; preferably for 1 to 6 hours and more preferably for 1 to 4 hours.

[0135]

[0053] In still another embodiment of the present invention, step (c) sodium salt formation reaction can be performed with or without isolation of step (b) of bis[2-(perfluorohexyl)ethyl] hydrogenphosphate compound of formula (I).

[0136]

[0054] In step (c), the sodium salt formation reaction can be carried out at temperature of -20 °C to 30 °C; preferably at 10 °C to 30 °C and more preferably at 25 °C to 30 °C.

[0137]

[0055] In step (c), the sodium salt formation reaction can be carried out for 1 to 10 hours; preferably for 1 to 5 hours and more preferably for 1 to 3 hours.

[0138]

[0056] The present invention is more particularly described in the following examples that are intended as illustration only, since numerous modifications and variations within the scope of the present invention will be apparent to those skilled in the art. Unless otherwise noted, all reagents used in the examples were obtained or are available from the chemical suppliers.

[0139]

[0057] The following examples illustrate the basic methodology and versatility of the present invention.

[0140] EXAMPLES:

[0141] Example 1: Preparation of solution of sodium bis[2-(perfluorohexyl)ethyl] phosphate

[0142]

[0058] Charged MTBE (400 mL), phosphoryl chloride (42 g) into a reaction vessel and slowly cooled the reaction mixture at 0 °C to 5 °C. Simultaneously, prepared a homogenous clear solution of lH,lH,2H,2H-perfluoro-l -octanol (200 g) and triethylamine (56 g) in MTBE (200 mL) at 25°C to 30 °C under stirring. Further, resulting homogenous clear solution was cooled to 5 °C to 10 °C and added to the above reaction mixture containing phosphoryl chloride in MTBE at 0 °C to 5 °C over a period of 1.5 hours to 2.0 hours. Resulting reaction mixture was stirred under nitrogen for 1.0 hours at 0°C to 5 °C and slowly heated to 25 °C to 35°C and stirred for 3 hours at same temperature. After completion of reaction, slowly DM water (120 g) was added and reaction mixture was allowed to separate organic and aqueous layers. DM water (180 g) was added to the resulting organic layer containing product and stirred for 4 hours at 25 °C to 35°C and reaction mixture was allowed to separate organic and aqueous layers. From the resulting organic layer MTBE was recovered atmospherically at 60 °C to 70 °C to obtain oily residue. IP A (230 g) and water (620 g) were added to the oily residue. Further, pH of the reaction mixture was adjusted to 7 to 9 by addition of 50% aqueous NaOH solution to obtain solution of sodium bis[2-(perfluorohexyl)ethyl] phosphate (H40 g).

[0143] Surface Tension: 16.8 mN / m2; Specific Gravity: 1.03140; Solid Content: 17.47;

[0144] Molar Yield of sodium bis[2-(perfluorohexyl)ethyl] phosphate based on Solid content: 89.28%.

[0145] 19F NMR (282.02 MHz, CD3OD): -127.35 (m, 4F), -124.67 (m, 4F), -123.94 (m, 4F), -122.964 (m, 4F), -114.55 (m, 4F), -82.37 (m, 6F) 5ppm.

[0146] 31P NMR (121.44 MHz, CD3OD): -0.205ppm

[0147] Example 2: Preparation of solution of ammonium bis[2-(perfluorohexyl)ethyl] phosphate

[0148]

[0059] Charged MTBE (200 mL), phosphoryl chloride (21 g) into a reaction vessel and slowly cooled the reaction mixture at 0 °C to 5 °C. Simultaneously, prepared a homogenous clear solution of lH,lH,2H,2H-perfluoro-l -octanol (100 g) and triethylamine (29 g) in MTBE (100 mL) at 25°C to 30 °C under stirring. Further, resulting homogenous clear solution was cooled to 5 °C to 10 °C and added to the above reaction mixture containing phosphoryl chloride in MTBE at 0 °C to 5 °C over a period of 1.5 hours to 2.0 hours. Resulting reaction mixture was stirred under nitrogen for 1.0 hours at 0°C to 5 °C and slowly to heated to 25 °C to 35°C and stirred for 3 hours at same temperature. After completion of reaction, slowly DM water (60 g) was added and reaction mixture was allowed to separate organic and aqueous layers. DM water (90 g) was added to the resulting organic layer containing product and stirred for 4 hours at 25 °C to 35°C and reaction mixture was allowed to separate lower aqueous layers. From the resulting organic layer MTBE was recovered atmospherically at 60 °C to 70 °C to obtain oily residue. IPA (115 g) and water (305 g) was added to the oily residue and the pH of the reaction mixture was adjusted to 7 to 9 by addition of 25% aqueous ammonia solution to obtain solution of ammonium bis[2-(perfluorohexyl)ethyl] phosphate (554 g).

[0149] Surface Tension: 17.5 mN / m2; Specific Gravity: 1.01353; Solid Content: 17.79 Molar Yield of ammonium bis[2-(perfluorohexyl)ethyl] phosphate based on Solid content: 88.91%.

[0150] 19F NMR (282.02 MHz, CD3OD): -127.41 (m, 4F), -124.67 (m, 4F), -123.97 (m, 4F), -122.97 (m, 4F), -114.63 (m, 4F), -82.47 (m, 6F) 5ppm

[0151] 31P NMR (121.44 MHz, CD3OD): -0.28 5ppm

[0152] Example 3: Preparation of bis[2-(perfluorohexyl)ethyl] hydrogen phosphate

[0060] Charged MTBE (400 mL), phosphoryl chloride (42 g) into reaction vessel and slowly cooled the reaction mixture at 0 °C to 5 °C. Simultaneously, prepared a homogenous clear solution of lH,lH,2H,2H-perfluoro-l -octanol (200 g) and triethylamine (58 g) in MTBE (200 mL) at 25°C to 30 °C under stirring. Further, resulting homogenous clear solution was cooled to 5 °C to 10 °C and added to the above reaction mixture containing phosphoryl chloride in MTBE at 0 °C to 5 °C over a period of 1.5 hours to 2.0 hours. Resulting reaction mixture was stirred under nitrogen for 1.0 hours at 0°C to 5 °C and slowly to heated to 25 °C to 35°C and stirred for 3 hours at same temperature. After completion of reaction, slowly DM water (120 g) was added and reaction mixture was allowed to separate organic and aqueous layers. DM water (180 g) was added to the resulting organic layer containing product and stirred for 4 hours at 25 °C to 35°C and reaction mixture was allowed to separate organic and aqueous layers. From the resulting organic layer MTBE was recovered atmospherically at 60 °C to 70 °C. The obtained oily product was then stripped off with IPA (100 g) and then degassed under vacuum for 2 hours to obtain white solid of bis[2-(perfluorohexyl)ethyl]hydrogen phosphate (210 g) with (Yield: 96.76%).

[0153] 19F NMR (282.02 MHz, CD3OD): -127.44 (m, 4F), -124.72 (m, 4F), -123.98 (m, 4F), -122.97 (m, 4F), -114.71 (m, 4F), -82.52 (m, 6F) 5ppm.

[0154] 31P NMR (121.44 MHz, CD3OD): -1.812 Sppm for main peak.

[0155] Example 4: Preparation of solution of sodium bis[2- (perfluorohexyl)ethyl] phosphate

[0156]

[0061] IPA (220 g) and water (600 g) were added to the bis[2-(perfluorohexyl)ethyl]hydrogen phosphate (200 g) and stirred the reaction mixture, followed by pH of the reaction mixture was adjusted to 7 to 9 by addition of 50% aqueous NaOH solution to obtain solution of sodium bis[2-(perfluorohexyl)ethyl]phosphate (1035 g).

[0157] Solid content: 17.44; Surface Tension: 17.3 mN / m2; Specific Gravity: 1.01116; Molar Yield of sodium bis[2-(perfluorohexyl)ethyl]phosphate based on Solid content:

[0158] 87.80%.

[0159] Example 5: Preparation of solution of ammonium bis[2-(perfluorohexyl)ethyl] phosphate

[0160]

[0062] IPA (220 g) and water (600 g) were added to the bis[2-(perfluorohexyl)ethyl] hydrogen phosphate (200 g) and stirred the reaction mixture, followed by pH of the reaction mixture was adjusted to 7 to 9 by addition of 25% ammonium hydroxide solution to obtain solution of ammonium bis[2-(perfluorohexyl)ethyl]phosphate (1044 g).

[0161] Solid content: 16.98; Surface Tension: 17.3 mN / m2; Specific Gravity: 1.01116; Molar Yield of ammonium bis[2-(perfluorohexyl)ethyl] phosphate based on Solid content:

[0162] 86.76%.

[0163] Example 6: Preparation of solution of sodium bis[2-(perfluorohexyl)ethyl] phosphate

[0164] a) Preparation of bis[2-(perfluorohexyl)ethyl] phosphorochloridate

[0165]

[0063] Charged MTBE (800 g), phosphoryl chloride (84.2 g) into a reaction vessel and slowly cooled the reaction mixture at 0 °C to 5 °C. Simultaneously, prepared a homogenous clear solution of lH,lH,2H,2H-perfluoro-l -octanol (400 g) and triethylamine (116 g) in MTBE (400 g) at 25°C to 30 °C under stirring. Further, resulting homogenous clear solution was cooled to 5 °C to 10 °C and added to the reaction mass containing phosphoryl chloride in MTBE at 0 °C to 5 °C over a period of 1.5 hours to 2.0 hours. The temperature of reaction mixture was slowly increased to 30 °C to 35 °C and stirred for 3 hours at same temperature. After completion of the reaction, the mixture was filtered and obtained solid wet cake was washed with MTBE (100 g). Resulting filtrate was distilled to recover MTBE and product as an oil. Further, obtained material was degassed at 75 °C under vacuum to obtain bis[2-(perfluorohexyl)ethyl]phosphorochloridate (425.7g, 95.84%).

[0166] 19F NMR (282.02 MHz, CD3OD): -127.36 (m, 4F), -124.65 (m, 4F), -123.93 (m, 4F), -122.92 (m, 4F), -114.66 (m, 4F), -82.43 (m, 6F) 5ppm.

[0167] b) Preparation of bis[2-(perfluorohexyl)ethyl] hydrogen phosphate

[0168]

[0064] MTBE (800 g) and water (400 g) were added to the above obtained bis[2-(perfluorohexyl)ethyl]phosphorochloridate (400 g) and stirred the reaction mass at ambient temperature for 9 hours. Further, resulting reaction mixture was allowed to separate aqueous and organic layer. Distilled out the solvent from the resulting reaction mixture to obtain bis[2-(perfluorohexyl)ethyl] hydrogen phosphate (370 g; 94.67%). c) Preparation of solution of sodium bis[2-(perfluorohexyl)ethyl] phosphate

[0065] The obtained solid bis[2-(perfluorohexyl)ethyl]hydrogenphosphate (100 g) was dissolved into isopropanol (115 g) and water (370 g) and pH of the reaction mixture was adjusted to 7 to 9 by addition of 10% NaOH aqueous solution to obtain solution of sodium bis[2-(perfluorohexyl)ethyl] phosphate (581 g).

[0169] Specific gravity: 1.02415; Surface Tension: 16.35 mN / m2; Solid Content: 16.1%w / w;

[0170] Molar Yield of sodium bis[2-(perfluorohexyl)ethyl] phosphate based on Solid content: 91.00%.

[0171] Example 7: Preparation of solution of ammonium bis[2-(perfluorohexyl)ethyl] phosphate

[0172] a) Preparation of bis[2-(perfluorohexyl)ethyl] phosphorochloridate

[0173]

[0066] Charged MTBE (800 g), phosphoryl chloride (84.2 g) into a reaction vessel and slowly cooled the reaction mixture at 0 °C to 5 °C. Simultaneously, prepared a homogenous clear solution of lH,lH,2H,2H-perfluoro-l -octanol (400 g) and triethylamine (116 g) in MTBE (400 g) at 25°C to 30 °C under stirring. Further, resulting homogenous clear solution was cooled to 5 °C to 10 °C and added to the above reaction mixture containing phosphoryl chloride in MTBE at 0 °C to 5 °C over a period of 1.5 hours to 2.0 hours. The temperature of reaction mixture was slowly increased to 30 °C to 35 °C and stirred for 3 hours at same temperature. After completion of the reaction, the mixture was filtered and obtained solid wet cake was washed with MTBE (100 g). Resulting filtrate was distilled to recover MTBE and product as an oil. Further, obtained material was degassed at 75 °C under vacuum to obtain bis[2-(perfluorohexyl)ethyl] phosphorochloridate (425.7g, 95.84%).

[0174] b) Preparation of bis[2-(perfluorohexyl)ethyl] hydrogen phosphate

[0175]

[0067] MTBE (800 g) and water (400 g) were added to the above obtained bis[2-(perfluorohexyl)ethyl]phosphorochloridate (400 g) and stirred the reaction mass at ambient temperature for 9 hours. Further, resulting reaction mixture was allowed to separate aqueous and organic layer. Distilled out the solvent from the resulting reaction mixture to obtain bis[2-(perfluorohexyl)ethyl] hydrogen phosphate (370 g; 94.67%). c) Preparation of solution of ammonium bis[2-(perfluorohexyl)ethyl] phosphate

[0068] The obtained solid bis[2-(perfluorohexyl)ethyl] hydrogenphosphate (100 g) was dissolved into isopropanol (130 g) and water (310 g) and pH of the reaction mixture was adjusted to 7 to 9 by addition of 25% ammonium hydroxide solution to obtain solution of ammonium bis[2-(perfluorohexyl)ethyl] phosphate (556 g).

[0176] Specific gravity: 1.0375; Surface Tension: 17.05 mN / m2; Solid Content: 16.44% w / w;

[0177] Molar Yield of ammonium bis[2-(perfluorohexyl)ethyl] phosphate based on Solid content: 91.56%.

[0178] Example 8: Preparation of solution of sodium bis[2-(perfluorohexyl)ethyl] phosphate

[0179]

[0069] Charged mixture of MTBE and toluene (200 mL; 1 : 1 ratio), phosphoryl chloride (42 g) into reaction vessel and slowly cooled the reaction mixture at 0 °C to 5 °C. Simultaneously, prepared a homogenous clear solution of lH,lH,2H,2H-perfluoro-l-octanol (200 g) and tri ethylamine (58 g) in MTBE (400 mL) at 25 °C to 30 °C under stirring. Further, resulting homogenous clear solution was cooled to 5 °C to 10 °C and added to the above reaction mixture containing phosphoryl chloride in MTBE at 0 °C to 5 °C over a period of 1.5 hours to 2.0 hours. Resulting reaction mixture was stirred under nitrogen for 0.5 hours at 0°C to 5 °C and slowly heated to 25 °C to 35°C and stirred for 3 hours at same temperature. After completion of reaction, slowly DM water (120 g) was added and reaction mixture was allowed to separate organic and aqueous layers. DM water (180 g) was added to the resulting organic layer containing product stirred for 4 hours at 25 °C to 35°C and reaction mixture was allowed to separate organic and aqueous layers. From the resulting organic layer MTBE and toluene mixture was recovered atmospherically at 60 °C to 120 °C. The obtained residual mass was then degassed under vacuum for 2 hours to get oily mass in the reaction vessel. IPA (220 g) and water (600 g) was added to the residual oily mass. Further, pH of the reaction mixture was adjusted to 7 to 9 by addition of 50% NaOH aqueous solution and filtered the reaction mass to obtain solution of sodium bis[2-(perfluorohexyl)ethyl]phosphate (1097 g). Specific Gravity: 1.03440; Solid Content: 18.09% w / w; Molar Yield of sodium bis[2-(perfluorohexyl)ethyl] phosphate based on Solid content: 89.09%.

[0180] Example 9: Preparation of solution of ammonium bis[2-(perfluorohexyl)ethyl] phosphate

[0181]

[0070] Charged mixture of Toluene and MTBE (200 mL; 1 : 1 ratio), phosphoryl chloride (21 g) into a reaction vessel and slowly cooled the reaction mixture at 0 °C to 5 °C. Simultaneously, prepared a homogenous clear solution of lH,lH,2H,2H-perfluoro-l-octanol (100 g) and triethylamine (28 g) in MTBE (200 mL) at 25°C to 30 °C under stirring. Further, resulting homogenous clear solution was cooled to 5 °C to 10 °C and added to the above reaction mixture containing phosphoryl chloride in MTBE at 0 °C to 5 °C over a period of 1.5 hours to 2.0 hours. Resulting reaction mixture was stirred under nitrogen for 1.0 hours at 0°C to 5 °C and slowly heated to 25 °C to 35°C and stirred for 3 hours at same temperature. After completion of reaction, slowly DM water (120 g) was added and reaction mixture was allowed to separate organic and aqueous layers. DM water (180 g) was added to the resulting organic layer containing product and stirred for 4 hours at 25 °C to 35°C and reaction mixture was allowed to separate organic and aqueous layers. From the resulting organic layer MTBE and toluene mixture was recovered atmospherically at 60 °C to 120 °C. The obtained residual mass was then degassed under vacuum for 2 hours to get oily mass in the reaction vessel. IP A (220 g) and water (600 g) was added to the residual oily mass. Further, pH of the reaction mixture was adjusted to 7 to 9 by addition of 25% ammonium hydroxide solution and filtered the reaction mass to obtain solution of ammonium bis[2-(perfluorohexyl)ethyl] phosphate (534.5 g). Specific Gravity: 1.03160; Solid Content: 17.85%w / w; Molar Yield of ammonium bis[2-(perfluorohexyl)ethyl] phosphate based on solid content: 86.06%.

[0182] Example 10: Preparation of bis [2-(perfluorohexyl)ethyl] hydrogen phosphate

[0071] Charged mixture of toluene and MTBE (400 mL v / v; 1:1 ratio), phosphoryl chloride (42 g) into reaction vessel and slowly cooled the reaction mixture at 0 °C to 5 °C. Simultaneously, prepared a homogenous clear solution of lH,lH,2H,2H-perfluoro-1-octanol (200 g) and triethylamine (58 g) in MTBE (400 mL) at 25°C to 30 °C under stirring. Further, resulting homogenous clear solution was cooled to 5 °C to 10 °C and added to the above reaction mixture containing phosphoryl chloride in MTBE at 0 °C to 5 °C over a period of 1.5 hours to 2.0 hours. Resulting reaction mixture was stirred under nitrogen for 1.0 hours at 0°C to 5 °C and slowly to heated to 25 °C to 35°C and stirred for 3 hours at same temperature. After completion of reaction, slowly DM water (120 g) was added and reaction mixture was allowed to separate organic and aqueous layers. DM water (180 g) was added to the resulting organic layer containing product and stirred for 4 hours at 25 °C to 35°C and reaction mixture was allowed to separate lower aqueous layers. From the resulting organic layer toluene and MTBE mixture was recovered atmospherically at 60 °C to 120 °C. The obtained oily product was then stripped off with IPA (100 g) and then degassed under vacuum for 2 hours to obtain white solid of bis[2-(perfluorohexyl)ethyl] hydrogen phosphate (212 g) with (Yield: 97.69%).

[0183] Example 11: Preparation of solution of sodium bis[2-(perfluorohexyl)ethyl] phosphate

[0184]

[0072] IPA (110 g) and water (300 g) were added to the above bis[2-(perfluorohexyl)ethyl] hydrogen phosphate mass (100g) while stirring the reaction mixture, followed by pH of the reaction mixture was adjusted to 7 to 9 by addition of 10 % aqueous sodium hydroxide solution to obtain solution of sodium bis[2-(perfluorohexyl)ethyl] phosphate (541g).

[0185] Solid Content: 17.24%w / w; Specific Gravity: 1.036; Solid Content: 17.07% w / w; Molar Yield of sodium bis[2-(perfluorohexyl)ethyl] phosphate based on solid content: 89.84%.

[0186] Example 12: Preparation of solution of ammonium bis[2-(perfluorohexyl)ethyl] phosphate

[0187]

[0073] IPA (110 g) and water (300 g) were added to the above bis[2-(perfluorohexyl)ethyl] hydrogen phosphate mass (100 g) while stirring the reaction mixture, followed by pH of the reaction mixture was adjusted to 7 to 9 by addition of 25% aqueous ammonia solution to obtain solution of ammonium bis[2-(perfluorohexyl)ethyl] phosphate (525 g).

[0188] Solid Content: 17.33% w / w; Specific Gravity: 1.0353; Solid Content: 16.99% w / w Molar Yield of ammonium bis[2-(perfluorohexyl)ethyl] phosphate based on solid content: 87.31%.

[0189] Example 13: Preparation of solution of sodium bis[2-(perfluorohexyl)ethyl] phosphate

[0190] a) Preparation of bis[2-(perfluorohexyl)ethyl] phosphorochloridate

[0191]

[0074] Charged mixture of MTBE and toluene (200 mL; 1 : 1 ratio), phosphoryl chloride (21 g) into a reaction vessel and slowly cooled the reaction mixture at 0 °C to 5 °C. Simultaneously, prepared a homogenous clear solution of lH,lH,2H,2H-perfluoro-l-octanol (100 g) and tri ethylamine (28 g) in mixture of MTBE and toluene (200 mL; 1:1 ratio) at 25°C to 30 °C under stirring. Further, resulting homogenous clear solution was cooled to 5 °C to 10 °C and added to the above reaction mixture containing phosphoryl chloride in MTBE at 0 °C to 5 °C over a period of 1.5 hours to 2.0 hours. Resulting reaction mixture was stirred under nitrogen for 1.0 hours at 0°C to 5 °C and slowly heated to 25 °C to 35°C and stirred for 3 hours at same temperature. After completion of reaction, triethylamine hydrochloride salt was filtered and washed with MTBE (50 g). Further, combined filtrate was evaporated to obtain oily mass of bis[2-(perfluorohexyl)ethyl] phosphorochloridate (107 g; 96.36%).

[0192] 19F NMR (282.02 MHz, CD3OD): -127.49 (m, 4F), -124.77 (m, 4F), -124.72 (m, 4F), -123.02 (m, 4F), -114.76 (m, 4F), -82.60 (m, 6F) 5ppm. b) Preparation of bis [2-(perfluorohexyl)ethyl] hydrogen phosphate

[0193]

[0075] To the bis[2-(perfluorohexyl)ethyl] phosphorochloridate (100 g), mixture of toluene and MTBE [toluene (100 mL) + MTBE (200 mL)] was added. Further, slowly DM water (60 g) was added and reaction mixture was allowed to separate organic and aqueous layers. DM water (90 g) was added to the resulting organic layer containing product and stirred for 6 hours at 25 °C to 35 °C and reaction mixture was allowed to separate lower aqueous layers. From the resulting organic layer toluene and MTBE mixture was recovered atmospherically at 60 °C to 120 °C. The obtained oily product was then stripped off with IP A (50 g) and then degassed under vacuum for 2 hours to obtain white solid of bis[2-(perfluorohexyl)ethyl] hydrogen phosphate (94.23 g) with (Yield: 96.43%).

[0194] c) Preparation of solution of sodium bis[2-(perfluorohexyl)ethyl] phosphate

[0076] IPA (55 g) and water (150 g) were added to the above bis[2-(perfluorohexyl)ethyl] hydrogen phosphate (45.4 g) mass followed by pH of the reaction mixture was adjusted to 7 to 9 by addition of 10 % aqueous sodium hydroxide solution to obtain solution of sodium bis[2-(perfluorohexyl)ethyl] phosphate (262.5 g).

[0195] Surface Tension: 17.15 mN / m2; Solid Content: 17.5% w / w; Specific Gravity: 1.01353 Molar Yield of sodium bis[2-(perfluorohexyl)ethyl] phosphate based on solid content: 92.82%.

[0196] Example 14: Preparation of solution of ammonium bis[2-(perfluorohexyl)ethyl] phosphate

[0197] a) Preparation of bis[2-(perfluorohexyl)ethyl] phosphorochloridate

[0198]

[0077] Charged mixture of MTBE and toluene (200 mL; 1 : 1 ratio), phosphoryl chloride (21 g) into a reaction vessel and slowly cooled the reaction mixture at 0 °C to 5 °C. Simultaneously, prepared a homogenous clear solution of lH,lH,2H,2H-perfluoro-l-octanol (100 g) and tri ethylamine (28 g) in mixture of MTBE and toluene (200 mL; 1:1 ratio) at 25°C to 30 °C under stirring. Further, resulting homogenous clear solution was cooled to 5 °C to 10 °C and added to the above reaction mixture containing phosphoryl chloride in mixture of MTBE and toluene at 0 °C to 5 °C over a period of 1.5 hours to 2.0 hours. Resulting reaction mixture was stirred under nitrogen for 1.0 hours at 0°C to 5 °C and slowly heated to 25 °C to 35°C and stirred for 3 hours at same temperature. After completion of reaction, triethylamine hydrochloride salt was filtered and washed with MTBE (50 g). Further, combined filtrate was evaporated to obtain oily mass of bis[2-(perfluorohexyl)ethyl] phosphorochloridate (107 g; 96.36%).

[0199] 19F NMR (282.02 MHz, CD3OD): -127.49 (m, 4F), -124.77 (m, 4F), -124.72 (m, 4F), -123.02 (m, 4F), -114.76 (m, 4F), -82.60 (m, 6F) 5ppm.

[0200] b) Preparation of bis [2-(perfluorohexyl)ethyl] hydrogen phosphate

[0201]

[0078] To the bis[2-(perfluorohexyl)ethyl] phosphorochloridate (100 g), mixture of toluene and MTBE [ Toluene (100 mL) + MTBE (200 mL)] was added. Further, slowly DM water (60 g) was added and reaction mixture was allowed to separate organic and aqueous layers. DM water (90 g) was added to the resulting organic layer containing product and stirred for 6 hours at 25 °C to 35 °C and reaction mixture was allowed to separate lower aqueous layers. From the resulting organic layer toluene and MTBE mixture was recovered atmospherically at 60 °C to 120 °C to get oily mas. The obtained oily product was then stripped off with IP A (50 g) and then degassed under vacuum for 2 hours to obtain white solid of bis[2-(perfluorohexyl)ethyl] hydrogen phosphate (94.23 g) with (Yield: 96.43%).

[0202] c) Preparation of solution of ammonium bis[2-(perfluorohexyl)ethyl] phosphate

[0079] IPA (55g) and water (150 g) were added to the above bis[2-(perfluorohexyl)ethyl] hydrogen phosphate mass (45 g) while stirring the reaction mixture, followed by pH of the reaction mixture was adjusted to 7 to 9 by addition of 25% aqueous ammonia solution to obtain solution of ammonium bis[2-(perfluorohexyl)ethyl] phosphate (260 g).

[0203] Surface Tension: 17.5 mN / m2; Specific Gravity: 1.01353; Solid Content: 16.85% w / w Molar Yield of ammonium bis[2-(perfluorohexyl)ethyl] phosphate based on solid content: 95.3%.

[0204] Example 15: Preparation of bis[2-(perfluorohexyl)ethyl] hydrogen phosphate

[0080] Charged mixture of MDC and MTBE (1:1 v / v, 400 mL), phosphoryl chloride (42 g) into a reaction vessel and slowly cooled the reaction mixture at 0 °C to 5 °C. Simultaneously, prepared a homogenous clear solution of lH,lH,2H,2H-perfluoro-l-octanol (200 g) and tri ethylamine (58 g) in MTBE (400 mL) at 25 °C to 30 °C under stirring. Further, resulting homogenous clear solution was cooled to 5 °C to 10 °C and added to the above reaction mixture containing phosphoryl chloride in mixture of MDC and MTBE at 0 °C to 5 °C over a period of 1.5 hours to 2.0 hours. Resulting reaction mixture was stirred under nitrogen for 1.0 hours at 0°C to 5°C and slowly heated to 25 °C to 35 °C and stirred for 3 hours at same temperature. After completion of reaction, slowly DM water (120 g) was added, and reaction mixture was allowed to separate organic and aqueous layers. DM water (180 g) was added to the resulting organic layer containing product and stirred for 6 hours at 25 °C to 35°C and reaction mixture was allowed to separate organic and aqueous layers. From the resulting organic layer, MTBE and MDC mixture was recovered atmospherically at 40 °C to 70 °C. The obtained oily product was then stripped off with IP A (100 g) and then degassed under vacuum for 2 hours to obtain white solid of bis[2-(perfluorohexyl)ethyl]hydrogen phosphate (206.8 g) with (Yield: 95.29%).

[0205] Example 16: Preparation of bis[2-(perfluorohexyl)ethyl] hydrogen phosphate

[0081] Charged phosphoryl chloride (59 g), MTBE (440 g) into a reaction vessel and slowly cooled the reaction mixture at 0 °C to 5 °C. Simultaneously, prepared a homogenous clear solution of lH,lH,2H,2H-perfluoro-l -octanol (200 g) and triethylamine (58 g) in dichloromethane (180 g) at 25°C to 30 °C under stirring. Further, resulting homogenous clear solution was cooled to 5 °C to 10 °C and added to the above reaction mixture containing phosphoryl chloride in MTBE at 0 °C to 5 °C with stirring. The temperature of reaction mixture was slowly increased to 30 °C to 35 °C and stirred for 8 hours at same temperature. After completion reaction, slowly water (100 g) was added to the reaction mixture and mixture was allowed layers to separate. Distilled out the mixture of solvent (DCM+MTBE). Further, obtained oily product was degassed at 60°C under vacuum to get bis[2-(perfluorohexyl)ethyl] hydrogen phosphate (190g, 87.55%).

[0206] Example 17: Preparation of sodium salt of bis[2-(perfluorohexyl)ethyl] phosphate

[0082] The solution of sodium bis[2-(perfhrorohexyl)ethyl] phosphate (500 g) was distilled to remove solvent under vacuum at 50 °C to 60 °C, further solid was degassed for 4 hours to obtain sodium salt of bis[2-(perfluorohexyl)ethyl] phosphate (84 g).

[0207] 19F NMR (282.02 MHz, CD3OD): -127.42 (m, 4F), -124.73 (m, 4F), -123.96 (m, 4F), -123.94 (m, 4F), -114.64 (m, 4F), -82.49 (m, 6F) 5ppm;31P NMR (121.44 MHz, CD3OD): -0.125ppm.

[0208] Example 18: Preparation of solution of sodium bis[2-(perfluorohexyl)ethyl] phosphate

[0209] a) Preparation of bis[2-(perfluorohexyl)ethyl] hydrogen phosphate

[0210]

[0083] Charged cyclopentyl methyl ether (200 mL), phosphoryl chloride (21.5 g) into a reaction vessel and slowly cooled the reaction mixture at 0 °C to 5 °C. Simultaneously, prepared a homogenous clear solution of lH,lH,2H,2H-perfluoro-l -octanol (100 g) and triethylamine (29.1 g) in CPME (100 mL) at 25°C to 30 °C under stirring. Further, resulting homogenous clear solution was cooled to 5 °C to 10 °C and added to the above reaction mixture containing phosphoryl chloride in CPME at 0 °C to 5 °C over a period of 1.5 hours to 2.0 hours. Resulting reaction mixture was stirred under nitrogen for 1.0 hours at 0°C to 5 °C and slowly heated to 25 °C to 35°C and stirred for 3 hours at same temperature. After completion of reaction, slowly DM water (90 g) was added and reaction mixture was allowed to separate aqueous and organic layers. Further, resulting organic contain bis[2-(perfluorohexyl)ethyl] hydrogen phosphate (98 g; 88.3%).

[0211] b) Preparation of solution of sodium bis[2-(perfluorohexyl)ethyl] phosphate

[0084] IPA (86g) and water (264 g) were added to the above bis[2-(perfluorohexyl)ethyl] hydrogen phosphate mass (82 g) followed by pH of the reaction mixture was adjusted to 7 to 9 by addition of 48% aqueous sodium hydroxide solution to obtain solution of sodium bis[2-(perfluorohexyl)ethyl] phosphate (430 g).

[0212] Surface Tension: 16.95 mN / m2; Specific Gravity: 1.03; Solid Content: 18.0; Molar Yield of sodium bis[2-(perfluorohexyl)ethyl] phosphate based on Solid content:

[0213] 91.83%.

[0214]

[0085] Various modifications of the embodiments, in addition to those described herein, will be apparent to those skilled in the art from the foregoing description. Such modifications are also intended to fall within the scope of the appended claims. Each reference, including all patent, patent applications, and publications, cited in the present application is incorporated herein by reference in its entirety.

Claims

CLAIMS:

1. A process for the preparation of bis[2-(perfluorohexyl)ethyl]phosphate compound of formula (I) or salts (Is) thereof,OH OH QF13'C6F31 ^ ' P ' ^C6F JII3.Salt o oFormula (I) Formula (Is) comprising the steps of:a. reacting perfluorohexyl ethyl alcohol compound of formula (II) with phosphoryl chloride compound of formula (III) in the presence of organic base in first solvent to obtain bis[2-(perfluorohexyl)ethyl]phosphorochloridate compound of formula (IV);O Cl II Organic Base ^^^OH + Cl— p— Cl I First Solvent Cl OFormula (II) Formula (III) Formula (IV) b. hydrolyzing the step (a) bis[2-(perfluorohexyl)ethyl]phosphorochloridate compound of formula (IV) in the presence of water and first solvent to obtain bis[2-(perfluorohexyl)ethyl] hydrogenphosphate compound of formula (I); and ci Water OH First Solvent C6FB P C6F13o O Formula (IV) Formula (I)c. optionally, treating bis[2-(perfluorohexyl)ethyl] hydrogenphosphate compound of formula (I) with base in second solvent to obtain salt of bis[2- (perfluorohexyl)ethyl] phosphate compound of formula (Is).OHBase Second Solvent oFormula (I) Formula (Is) wherein the step a) and b) or a) to c) are performed in one pot process.

2. A process for preparation of a solution comprising bis[2-(perfluorohexyl) ethyl]phosphate compound of formula (I) or salts (Is) thereof,OH OH^6^13* ■'p-' \ ■c6F13C6F13P CgFi3ll II .SaltO oFormula (I) or Formula (Is)comprising the steps of:a. reacting perfluorohexyl ethyl alcohol compound of formula (II) with phosphoryl chloride compound of formula (III) in the presence of organic base in first solvent to obtain bis[2-(perfluorohexyl)ethyl]phosphorochloridate compound of formula (IV);o Organic Base ‘OH ll + Cl— p— Cl I First SolventCl Formula (II) Formula (III) Formula (IV)b. hydrolyzing the step (a) bis[2-(perfluorohexyl)ethyl]phosphorochloridate compound of formula (IV) in the presence of water and first solvent to obtain bis[2-(perfluorohexyl)ethyl] hydrogenphosphate compound of formula (I); and Cl Water OH l ^( First Solvent C6F13 P ‘C6F13IIo o Formula (IV) Formula (I)c. treating bis[2-(perfluorohexyl)ethyl]hydrogenphosphate compound of formula (I) with base in second solvent to obtain salts of bis[2-(perfluorohexyl)ethyl] phosphate compound of formula (I) solution.OHBase Second Solvent oFormula (I) Formula (Is) wherein the step a) and b) or a) to c) are performed in one pot process.

3. The process as claimed in claim 1 or 2, wherein the base used in step (a) is selected from pyridine, 4-dimethylaminopyridine (DMAP), N-methyl imidazole, triethyl amine, l,8-diazabicyclo[5.4.0]undec-7-ene (DBU), l,5-diazabicyclo[4.3.0]non-5- ene (DBN) or mixture(s) thereof.

4. The process as claimed in claim 1 or 2, wherein the first solvent in step (a) is selected from methyl tertiary butyl ether (MTBE) or a mixture of MTBE and organic solventor cyclopentyl methyl ether (CPME) or a mixture of cyclopentyl methyl ether (CPME) and organic solvent.

5. The process as claimed in claim 4, wherein the organic solvent is selected from ethers such as diethyl ether, tetrahydrofuran; hydrocarbon solvents such as toluene, dichloromethane, ethylene dichloride, xylenes, mesyteline, open or closed crown ethers such as monoglyme, diglyme or mixture(s) thereof.

6. The process as claimed in claim 1 or 2, wherein the second solvent in step (c) is selected from polar protic solvents such as Ci to Cio alcohol, water or mixture(s) thereof.

7. The process as claimed in claim 1 or 2, wherein the base in step (c) is selected from ammonia, sodium hydroxide, butyl amine or tetramethyl ammonium hydroxide.

8. A process for preparation of sodium salt of bis[2-(perfluorohexyl)ethyl] phosphate compound of formula (la),CgFis'Formula (la)comprising the steps of:a. reacting perfluorohexyl ethyl alcohol compound of formula (II) with phosphoryl chloride compound of formula (III) in the presence of triethyl amine in MTBE to obtain bis[2-(perfluorohexyl)ethyl]phosphorochloridate compound of formula (IV);+ Cl— p— Cl MTBE ‘C6F13O Formula (II) Formula (III) Formula (IV)b. hydrolyzing the step (a) bis[2-(perfluorohexyl)ethyl]phosphorochloridate compound of formula (IV) in the presence of water and MTBE to obtain bis[2- (perfluorohexyl)ethyl] phosphate compound of formula (I); andWater OHMTBEFormula (IV) Formula (I) c. treating bis[2-(perfluorohexyl)ethyl]hydrogenphosphate compound of formula (I) with sodium hydroxide in isopropyl alcohol to obtain sodium salt of bis[2- (perfluorohexyl)ethyl] phosphate compound of formula (la).Na OFormula (I) Formula (la) wherein the step (a) and (b) or (a) to (c) are performed in one pot process.

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