Classifications

• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
  • C07C51/00—Preparation of carboxylic acids or their salts, halides or anhydrides
  • C07C51/09—Preparation of carboxylic acids or their salts, halides or anhydrides from carboxylic acid esters or lactones
• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
  • C07C67/00—Preparation of carboxylic acid esters
  • C07C67/30—Preparation of carboxylic acid esters by modifying the acid moiety of the ester, such modification not being an introduction of an ester group
• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
  • C07C67/00—Preparation of carboxylic acid esters
  • C07C67/30—Preparation of carboxylic acid esters by modifying the acid moiety of the ester, such modification not being an introduction of an ester group
  • C07C67/31—Preparation of carboxylic acid esters by modifying the acid moiety of the ester, such modification not being an introduction of an ester group by introduction of functional groups containing oxygen only in singly bound form
• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
  • C07C67/00—Preparation of carboxylic acid esters
  • C07C67/30—Preparation of carboxylic acid esters by modifying the acid moiety of the ester, such modification not being an introduction of an ester group
  • C07C67/313—Preparation of carboxylic acid esters by modifying the acid moiety of the ester, such modification not being an introduction of an ester group by introduction of doubly bound oxygen containing functional groups, e.g. carboxyl groups
• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
  • C07C67/00—Preparation of carboxylic acid esters
  • C07C67/30—Preparation of carboxylic acid esters by modifying the acid moiety of the ester, such modification not being an introduction of an ester group
  • C07C67/317—Preparation of carboxylic acid esters by modifying the acid moiety of the ester, such modification not being an introduction of an ester group by splitting-off hydrogen or functional groups; by hydrogenolysis of functional groups
  • C07C67/327—Preparation of carboxylic acid esters by modifying the acid moiety of the ester, such modification not being an introduction of an ester group by splitting-off hydrogen or functional groups; by hydrogenolysis of functional groups by elimination of functional groups containing oxygen only in singly bound form
• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
  • C07C67/00—Preparation of carboxylic acid esters
  • C07C67/30—Preparation of carboxylic acid esters by modifying the acid moiety of the ester, such modification not being an introduction of an ester group
  • C07C67/333—Preparation of carboxylic acid esters by modifying the acid moiety of the ester, such modification not being an introduction of an ester group by isomerisation; by change of size of the carbon skeleton
  • C07C67/343—Preparation of carboxylic acid esters by modifying the acid moiety of the ester, such modification not being an introduction of an ester group by isomerisation; by change of size of the carbon skeleton by increase in the number of carbon atoms

Definitions

• WO2012/041872 discloses novel N-heteroaryl compounds that are useful as medicaments. This patent application also discloses the dehydration of ethyl 4,4,5,5-tetrafluoro-3-hydroxy-pentanoate to ethyl (E)-4,4,5,5-tetrafluoropent-2-enoate using phosphorous pentoxide (P 2 O 5 ).
• WO2012/041873 discloses novel N-heteroaryl compounds that are useful as medicaments. This patent application also discloses the dehydration of ethyl 4,4,5,5,5-pentafluoro-3-hydroxy-pentanoate to ethyl (E)-4,4,5,5,5-pentafluoropent-2-enoate using phosphorous pentoxide (P 2 O 5 ).
• WO2013/144179 discloses novel heteroaryl compounds that are useful as medicaments. This patent application also discloses the dehydration of ethyl 4,4 difluoro-3-hydroxy-pentanoate to ethyl (E)-4,4-difluoropent-2-enoate using diphenyl-2-pyridylphosphine and di-butylazodicarboxylate.
• WO2013/144180 discloses novel heteroaryl compounds that are useful as medicaments. This patent application also discloses the dehydration of ethyl 4,4 difluoro-3-hydroxy-pentanoate to ethyl (E)-4,4-difluoropent-2-enoate using diphenyl-2-pyridylphosphine and di-butylazodicarboxylate.
• Tamura et al. Journal of Fluorine Chemistry 126 (2005) 918-930 discloses a dehydration reaction using tosyl choride and triethylamine (TEA)
• Yamazaki et al., Tetrahedron: Asymmetry 1 (1990) 521-524 also discloses a dehydration reaction using tosyl choride and triethylamine (TEA).
• TAA triethylamine
• This invention relates to an improved process for making crotonic acid intermediates which can be used to make compounds that can be used as medicaments.
• An embodiment of the invention is a process to prepare a compound of Formula (I)
• R 3 , R 4 and R 5 are each selected independently from hydrogen, halogen, alkyl, alkenyl, alkynyl, alkoxyl, and wherein the alkyl, alkenyl, alkynyl, and alkoxyl may be optionally substituted with one or more halogen, alkyl, alkenyl, alkynyl, and alkoxyl;
• step a) is an amine.
• the amine is triethylamine.
• the reagent of step b) is an acid or a base.
• the reagent is a base.
• the base is sodium hydroxide, lithium hydroxide or potassium hydroxide.
• the base is sodium hydroxide.
• the process further comprises a process for preparing a compound of Formula (V)
• R 3 , R 4 , R 5 , and R 6 are defined as above; comprising
• the base of step i) is LiHMDS, sodium hydride, LDA, KOtBu or NaOEt.
• the reducing agent of step ii) is lithium borohydride, sodium borohydride, disiamylborane, hydrogen with platinum (IV) oxide, hydrogen with palladium/carbon or zinc borohydride.
• the reducing agent is sodium borohydride.
• R 3 , R 4 and R 5 is halogen.
• the halogen is bromine, chlorine or fluorine.
• at least one of R 3 , R 4 and R 5 is alkyl.
• R 3 is CH 3 and R 4 and R 5 are both fluorine.
• R 3 is Cl and R 4 and R 5 are both fluorine.
• R 3 is Br and R 4 and R 5 are both fluorine.
• R 3 is CF 3 , R 4 is CH 3 O and R 5 is fluorine.
• R 3 is CH 3 and R 4 and R 5 are both chlorine.
• R 3 is CF 3 , R 4 is chlorine and R 5 is fluorine.
• R 3 and R 4 are both fluorine R 5 is hydrogen.
• R 3 is CHF 2
• R 4 and R 5 are fluorine.
• R 6 is ethyl.
• R 7 is ethyl.
• R 7 is methyl.
• WO2012/041872, WO2012/041873, WO2013/144179 and WO2013/144180 disclose processes to prepare substituted pent-2-enoates and but-2-enoates from the corresponding 3-hydroxy-pentanoates and 3-hydroxy-butanoates, respectively.
• phosphorous pentoxide P 2 O 5
• diphenyl-2-pyridylphosphine and di-butylazodicarboxylate were used as reagents for these dehydration reactions.
• Other references have disclosed the use of triphenylphosphine and diethyl azodicarboxylate (DEAD) or tosyl chloride and triethylamnine as reagents for similar reactions (see Jagodzinska, Bevilaqua, Tamura and Yamazaki above). These reagents offer several disadvantages when the process is conducted on commercial scale.
• triphenylphosphine and diethylazodicarboxylate are used for the dehydration reaction, byproducts (triphenylphosphine oxide and diethoxycarboxyhydrazine) are formed which make purification of the desired reaction product difficult. Chromatographic separation is often required which is undesired and often impractical at a commercial scale.
• diethylazodicarboxylate is an expensive reagent that is light and oxygen sensitive and thermally unstable which can lead to uncontrollable runaway reactions. Transport of this reagent is severely restricted and limited to only solutions, not the pure form. Triphenylphosphine is also sensitive against oxygen and air. Furthermore, it generates large waste streams due to an unfavourable mass balance.
• Diphenyl-2-pyridylphosphine and di-butylazodicarboxylate have been used as alternatives to triphenylphosphine and diethylazodicarboxylate for the dehydration reaction (see WO2013/144179 and WO2013/144180).
• the cost of these reagents is prohibitive for a commercial process.
• the phosphorpentoxide reagent (P 2 O 5 ) reagent used in the dehydration reactions of the cited references is a solid and was used in the cited references without any solvent. On a large scale, efficient mixing of solids is not possible. Moreover, when solids are mixed there is little dissipation of generated reaction heat, and this poses a severe safety risk.
• Tosylchloride is also a solid and as noted above with P 2 O 5 is more difficult to handle on a larger scale than the scale of the reactions disclosed in the cited references (see Tamura et al. and Yamazaki et al.). Furthermore, precautions must be taken to avoid exposure to dust. Liquids are easier to handle on large scale, especially in a production environment.
• An embodiment of the invention is a process to prepare a compound of Formula (I)
• R 3 , R 4 and R 5 are each selected independently from hydrogen, halogen, alkyl, alkenyl, alkynyl, alkoxyl, and wherein the alkyl, alkenyl, alkynyl, and alkoxyl may be optionally substituted with one or more halogen, alkyl, alkenyl, alkynyl, and alkoxyl; comprising
• step a) is an amine.
• the amine is triethylamine.
• the reagent of step b) is an acid or a base.
• the reagent is a base.
• the base is sodium hydroxide, lithium hydroxide or potassium hydroxide.
• the base is sodium hydroxide.
• Suitable solvents for step b) comprise solvents that are miscible with water like THF, EtOH, MeOH or isopropanol.
• the reaction of step b) is done in a mixture of such a solvent and water.
• Other suitable solvents comprise solvents that are immiscible with water like toluene.
• the reaction of step b) is done in a mixture of such a solvent with water such that a biphasic mixture is used.
• Suitable reaction temperatures for step b) range from ⁇ 10° C. to 60° C. In an embodiment, the temperature range is from 0° C. to 25° C. In another embodiment, the temperature range is from 25° C. to 40° C. In another embodiment, the temperature range is from 40° C. to 50° C.
• methanesulfonic acid chloride is used advantageously in excess related to (V) in a ratio of 1:1 to 2:1.
• the methane sulfonic acid chloride is used in a ratio of 1:1 to 1.5:1 or in a ratio of 1.25:1 to 1.3:1 or in a ratio of 1.05 to 1.1.
• the base in step a) is used advantageously in excess related to (V) in a ratio of 2:1 to 8:1, In other embodiments, the ratio is 2:1 to 5:1, or the ratio is 2:1 to 3:1.
• the reaction of step a) can be performed in such a way that the base is added in one portion or can be performed in a stepwise manner advantageously compound (V) is combined with 1 to 1.2 equivalents of base followed by the addition of MesCl followed by additional base.
• Suitable temperature for the addition of MesCl in step a) ranges from ⁇ 10° C. to 25° C. In another embodiment, the temperature is from ⁇ 5° C. to 0° C. In another embodiment the temperature is from 0° C. to 10° C.
• the reaction is stirred at a suitable temperature to complete formation of the intermediate methane sulfonic ester of (V). Suitable temperature for this reaction ranges from 0° C. to 30° C. Afterwards, the remaining excess of base is added. Suitable temperature for the addition of the excess base ranges from ⁇ 10° C. to 25° C. In another embodiment, the suitable temperature for the addition of the excess base ranges from 0° C. to 25° C.
• Suitable temperature for this stirring period ranges from 0° C. to 40° C. In another embodiment, the suitable temperature for the stirring period ranges from 10° C. to 25° C. In another embodiment, the suitable temperature for the stirring period ranges from 20° C. to 30° C.
• Suitable solvents for step a) include halogenated solvents like dichloromethane (DCM), chloroform, dichloroethane and other solvents like tetrahydrofuran (THF), 2-methyl-THF, toluene, benzene, EtOAc.
• DCM dichloromethane
• THF tetrahydrofuran
• 2-methyl-THF 2-methyl-THF
• toluene toluene
• EtOAc EtOAc
• the solvent is DCM.
• the solvent is toluene.
• the solvents for steps a) and b) are different. In another embodiment, the solvent for step a) is the same as for step b).
• the base used is triethyl amine
• the solvent used is DCM and the temperature of the reaction is from 0° C. to 25° C.
• the base used is triethyl amine
• the solvent used is DCM and the temperature of the reaction is from 0° C. to 25° C. and the triethyl amine is added stepwise, a portion being added before or with the methane sulfonyl chloride and a portion being added after the addition of the methane sulfonyl chloride.
• the base used is triethylamine
• the solvent used is toluene and the temperature of the reaction is from 0° C. to 30° C.
• the base used is triethylamine
• the solvent used is toluene
• the temperature of the reaction is from 0° C. to 30° C. and the triethyl amine is added stepwise, a portion being added before or with the methane sulfonyl chloride and a portion being added after the addition of the methane sulfonyl chloride.
• the raw product (VI) can be purified or used without purification in the next step.
• Methods for purification include chromatography on silica or distillation.
• the raw product (VI) is purified by distillation.
• the distillation is at reduced pressure.
• the distillation is performed in a short path distillation equipment.
• the raw product (VI) is used directly in step b)
• the yield for step a) ranges from 40% to 90%. In another embodiment, the yield ranges from 50% to 85%. In another embodiment, the yield ranges from 60% to 80%.
• the process further comprises a process for preparing a compound of Formula (V)
• R 3 , R 4 , R 5 , and R 6 are defined as above; comprising
• the base of step i) is LiHMDS, sodium hydride, LDA, KOtBu or NaOEt.
• Step i) is preferably done in a solvent.
• the solvent can be an ether-derived solvent like diethyl ether, methyl tert-butyl ether, THF, 2-methyl-THF, 1,4-dioxane or cyclopentyl methyl ether or a hydrocarbon solvent like toluene.
• the reaction temperature can range from ⁇ 78° C. to 80° C., preferably from 0° C. to 65° C. In an embodiment the temperature ranges from 50° C. to 60° C.
• the raw product of compound (IV) is typically subjected to an aqueous quench or work-up which can include the addition of a solution of an acid like hydrochloride acid or ammonium chloride or the addition of a base like sodium carbonate or sodium bicarbonate or the simultaneous addition of an acid and a base. Following the quench or work-up, the raw product (IV) can be used directly in step ii). In another embodiment, compound (IV) is isolated and then used in step ii). In yet another embodiment, compound (IV) is isolated and purified by distillation or column chromatography and then used in step ii).
• the reducing agent of step ii) is lithium borohydride, sodium borohydride, disiamylborane, hydrogen with platinum (IV) oxide, hydrogen with palladium/carbon or zinc borohydride.
• the reducing agent is sodium borohydride.
• Suitable solvents for step ii) include ether-derived solvent like diethyl ether, methyl tert-butyl ether, THF, 2-methyl-THF, 1,4-dioxane or cyclopentyl methyl ether or inert solvents like toluene.
• the solvents for steps i) and ii) are different.
• the solvent for step i) is the same as for step ii).
• the reducing agent for step ii) is added at a temperature that can range from ⁇ 10° C. to 25° C. In an embodiment, the addition is done at 0° C., in another embodiment the addition is done at a temperature from 20° C. to 25° C.
• the reaction in step ii) is continued at a temperature that ranges from ⁇ 10° C. to 25° C. In one embodiment, the reaction is continued at 0° C., in another embodiment the reaction is continued at a temperature from 20° C. to 25° C.
• steps i), ii), a) and b) of the process are conducted without isolation of the intermediate compounds of Formulas (IV), (V) or (VI).
• At least one of R 3 , R 4 and R 5 is halogen.
• the halogen is bromine, chlorine or fluorine.
• R 3 , R 4 and R 5 is alkyl.
• R 3 is CH 3 and R 4 and R 5 are both fluorine.
• R 3 is Cl and R 4 and R 5 are both fluorine.
• R 3 is Br and R 4 and R 5 are both fluorine.
• R 3 is CF 3 , R 4 is CH 3 O and R 5 is fluorine.
• R 3 is CH 3 and R 4 and R 5 are both chlorine.
• R 3 is CF 3 , R 4 is chlorine and R 5 is fluorine.
• R 6 is ethyl.
• R 7 is ethyl.
• R 7 is methyl.
• Alkyl means an aliphatic hydrocarbon group which may be straight or branched and comprising about 1 to about 20 carbon atoms in the chain. In one embodiment alkyl groups contain about 1 to about 12 carbon atoms in the chain. In another embodiment alkyl groups contain about 1 to about 6 carbon atoms in the chain. Branched means that one or more lower alkyl groups such as methyl, ethyl or propyl, are attached to a linear alkyl chain. “Lower alkyl” means a group having about 1 to about 6 carbon atoms in the chain which may be straight or branched.
• Non-limiting examples of suitable alkyl groups include methyl, ethyl, n-propyl, isopropyl, n-butyl, t-butyl, n-pentyl, heptyl, nonyl, or decyl.
• Alkylene means a divalent group obtained by removal of a hydrogen atom from an alkyl group that is defined above.
• alkylene include methylene, ethylene and propylene.
• alkylene groups have about 1-18 carbon atoms in the chain, which may be straight or branched.
• alkylene groups have about 1-12 carbon atoms in the chain, which may be straight or branched.
• alkylene groups may be lower alkylenes.
• “Lower alkylene” means an alkylene having about 1 to 6 carbon atoms in the chain, which may be straight or branched.
• Alkenyl means an aliphatic hydrocarbon group containing at least one carbon-carbon double bond and which may be straight or branched and comprising about 2 to about 15 carbon atoms in the chain. In one embodiment alkenyl groups have about 2 to about 12 carbon atoms in the chain. In another embodiment alkenyl groups have about 2 to about 6 carbon atoms in the chain. Branched means that one or more lower alkyl groups such as methyl, ethyl or propyl, are attached to a linear alkenyl chain. “Lower alkenyl” means about 2 to about 6 carbon atoms in the chain which may be straight or branched.
• substituted alkenyl means that the alkenyl group may be substituted by one or more substituents which may be the same or different, each substituent being independently selected from the group consisting of halo, alkyl, aryl, cycloalkyl, cyano, alkoxy and —S(alkyl).
• substituents include ethenyl, propenyl, n-butenyl, 3-methylbut-2-enyl, n-pentenyl, octenyl and decenyl.
• Alkynyl means an aliphatic hydrocarbon group containing at least one carbon-carbon triple bond and which may be straight or branched and comprising about 2 to about 15 carbon atoms in the chain. In one embodiment alkynyl groups have about 2 to about 12 carbon atoms in the chain. In another embodiment alkynyl groups have about 2 to about 4 carbon atoms in the chain. Branched means that one or more lower alkyl groups such as methyl, ethyl or propyl, are attached to a linear alkynyl chain. “Lower alkynyl” means about 2 to about 6 carbon atoms in the chain which may be straight or branched.
• Non-limiting examples of suitable alkynyl groups include ethynyl, propynyl, 2-butynyl, 3-methylbutynyl, n-pentynyl, and decynyl.
• substituted alkynyl means that the alkynyl group may be substituted by one or more substituents which may be the same or different, each substituent being independently selected from the group consisting of alkyl, aryl and cycloalkyl.
• Halo (or “halogeno” or “halogen”) means fluoro, chloro, bromo, or iodo groups. Preferred are fluoro, chloro or bromo, and more preferred are fluoro and chloro.
• Haloalkyl means an alkyl as defined above wherein one or more hydrogen atoms on the alkyl are replaced by a halo group as defined above.
• Alkoxy means an —O-alkyl group in which the alkyl group is as previously described.
• suitable alkoxy groups include methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy and heptoxy.
• the bond to the parent moiety is through the ether oxygen.
• moieties e.g., substituents, groups or rings
• the phrases “one or more” and “at least one” mean that there can be as many moieties as chemically permitted, and the determination of the maximum number of such moieties is well within the knowledge of those skilled in the art.
• the term “independently”, in reference to the substitution of a parent moiety with one or more substituents, means that the parent moiety may be substituted with any of the listed substituents, either individually or in combination, and any number of chemically possible substituents may be used.
• substituted means that one or more hydrogens on the designated atom is replaced with a selection from the indicated group, provided that the designated atom's normal valency under the existing circumstances is not exceeded, and that the substitution results in a stable compound. Combinations of substituents and/or variables are permissible only if such combinations result in stable compounds.
• stable compound or “stable structure” is meant a compound that is sufficiently robust to survive isolation to a useful degree of purity from a reaction mixture, and formulation into an efficacious therapeutic agent.
• Solidate means a physical association of a compound of this invention with one or more solvent molecules.
• suitable solvates include ethanolates, methanolates, and the like.
• “Hydrate” is a solvate wherein the solvent molecule is H 2 O.
• salt(s) denotes acidic salts formed with inorganic and/or organic acids, as well as basic salts formed with inorganic and/or organic bases.
• TEA triethylamine.
• DCM dichloromethane.
• THF tetrahydrofuran.
• EtOH is ethanol.
• MeOH is methanol.
• EtOAc is ethyl acetate.
• Mesyl chloride or MesCl or MSC means methane sulfonyl chloride or methanesulfonic acid chloride.
• Tosyl chloride means p-toluene sulfonyl chloride.
• Reducing agent Non-limiting examples of reducing agents are lithium borohydride, sodium borohydride, disiamylborane, hydrogen with platinum(IV) oxide, hydrogen with palladium/carbon, zinc borohydride and the like.
• Step A Ethyl 4-bromo-4,4-difluoro-3-oxo-butanoate
• Lithium bis(trimethylsilyl)amide 200 ml of a 1M solution in THF, 0.2 mol was cooled to ⁇ 75° C. with stirring. A mixture of ethyl acetate (17 ml, 0.19 mol) and THF (15 ml) was charged with stirring over one hour while keeping the temperature at ⁇ 75° C. A mixture of ethyl 2-bromo-2,2-difluoroacetate (20 g, 0.099 mol) and THF (20 ml) was charged over one hour at the same temperature.
• the reaction mixture was quenched with a saturated aqueous solution of NH 4 Cl (150 ml) forming a slurry, the cooling bath was removed and the reaction mixture was allowed to reach room temperature overnight while stirring was continued.
• the mixture was acidified with aqueous HCl (1M) and the layers separated.
• the aqueous layer was extracted with EtOAc, the organic phases were combined, washed two times with aqueous HCl (1M) and with brine, dried over MgSO 4 and concentrated under reduced pressure.
• the residue was distilled under reduced pressure (6 mbar, 75° C.) to yield 19.1 gram (79% yield).
• Step B Ethyl 4-bromo-4,4-difluoro-3-hydroxy-butanoate
• Step D (E)-4-bromo-4,4-difluoro-but-2-enoic acid
• Ethyl 4,4-difluoro-3-oxo-butanoate (16 g from step A, 0.096 mol) was dissolved in toluene (250 ml) and cooled in an ice bath.
• Sodium borohydride (4 g, 0.106 mol) was charged portionwise with stirring. After 15 minutes, the ice bath was removed and the mixture was allowed to reach room temperature overnight while stirring was continued. The mixture was filtered, the filter residue washed with toluene, the filtrates were combined, cooled in an ice bath and acidified with HCl (1M). The layers were separated and the aqueous layer was extracted with EtOAc (2 times). The combined organic layers were washed with brine, dried over MgSO 4 and concentrated under reduced pressure.
• Ethyl (E)-4,4-difluoro-but-2-enoate (3.6 g from step C, 0.024 mol) was dissolved in THF (24 ml) and cooled down to 0° C. in an ice-bath. NaOH (4N, 14 ml) was charged in one portion. The mixture was stirred for 3 h at room temperature. The layers were separated and the organic layer was extracted with NaOH (2M). The combined aqueous layers were cooled again in an ice-bath, acidified to pH 1 with hydrochloric acid (6N) and then extracted with ethyl acetate (2 times). The combined organic layers were washed with brine, dried over Na 2 SO 4 and concentrated under reduced pressure.
• Step A Ethyl 4,4,5,5,5-pentafluoro-3-oxo-pentanoate
• Step B Ethyl 4,4,5,5,5-pentafluoro-3-hydroxy-pentanoate
• Ethyl 4,4,5,5,5-pentafluoro-3-hydroxy-pentanoate (11.3 g from step B, 0.048 mol) was combined with DCM (120 ml) and TEA (6.67 ml, 0.048 mol) and cooled in an ice bath.
• a solution of methanesulfonic acid chloride (5.59 ml, 0.072 mol) in DCM (30 ml) was added dropwise with stirring while the temperature was kept between 0° C. and 5° C. After the addition was complete, the cooling bath was removed and the mixture was stirred at ambient temperature for 4 hours. The mixture was cooled in an ice bath and TEA (13.34 ml, 0.096 mol) was added dropwise.
• Step D (E)-4,4,5,5,5-pentafluoropent-2-enoic acid
• the pH of the mixture from Step A was adjusted to 7.5 to 8.5 with conc. HCl. Subsequently, sodium borohydride (3.29 g, 0.087 mol) was added in portions while keeping the temperature between 15 and 25° C. and the pH below 9.5. After completion of addition the mixture was stirred for 1 hour. The pH was adjusted to 4-5 by the addition of conc. HCl and the layers were separated. The organic layer was washed with a solution of 1 g sodium bicarbonate in brine (50 ml), filtered through a short plug of magnesium sulfate, concentrated under reduced pressure to a volume of ca. 150 ml and carried to Step C.
• Step B The residue of Step B was diluted with toluene (300 ml) and cooled to 0° C. Methanesulfonylchloride (20.8 ml, 0.267 mol) was added followed by charging of triethylamine (39.1 ml, 0.28 mol) over 90 min while keeping the temperature below 10° C. Toluene (100 ml) was charged followed by triethylamine (50 ml, 0.357 mol) and the mixture was stirred overnight at room temperature. Water (100 ml) was added, the mixture was stirred until precipitates dissolved, the phases were separated and the organic phase was carried to Step D.

Landscapes

• Chemical & Material Sciences (AREA)
• Organic Chemistry (AREA)
• Engineering & Computer Science (AREA)
• Oil, Petroleum & Natural Gas (AREA)
• Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
• Pharmaceuticals Containing Other Organic And Inorganic Compounds (AREA)

Applications Claiming Priority (3)

Related Parent Applications (1)

Related Child Applications (1)

Publications (1)

Family

ID=50774649

Family Applications (2)

Family Applications After (1)

Country Status (5)

Families Citing this family (1)

Family Cites Families (5)

• 2015
  • 2015-05-20 EP EP15724253.8A patent/EP3145904A1/fr not_active Withdrawn
  • 2015-05-20 CN CN201580025915.0A patent/CN106458803A/zh active Pending
  • 2015-05-20 WO PCT/EP2015/061038 patent/WO2015177179A1/fr active Application Filing
  • 2015-05-20 US US15/312,013 patent/US20170121265A1/en not_active Abandoned
• 2016
  • 2016-11-16 CL CL2016002925A patent/CL2016002925A1/es unknown
• 2019
  • 2019-01-04 US US16/240,271 patent/US10562834B2/en not_active Expired - Fee Related

Also Published As

Similar Documents

Legal Events