BRPI0707521A2 - gemcitabine preparation - Google Patents

Abstract

PREPARATION OF GEMCITABINE. A process for the preparation of Gemcitabine hydrochloride and its purification.

Description

PREPARATION OF GEMCITABIN

INTRODUCTION TO THE INVENTION

The present invention relates to a process for preparing gemeitabine and its salts. In one aspect, the invention relates to a process which provides a gemeitabine hydrochloride free of its process related impurities.

Gemeitabine hydrochloride is the name adopted for a chemically known compound known as 2'-deoxy-2 ', 2'-difluoro-cytidine monohydrochloride (β-anomer) and having Formula I

<formula> formula see original document page 2 </formula>

Gemeitabine hydrochloride is a denucleoside analogue that has antitumor activity and is commercially available under the trademark GEMZAR0 as an injection. One vial of Gemzar contains gemeitabine hydrochloride equivalent to either 200 mg or 1 g gemeitabine baselivre.

Methods for the preparation of gemeitabine are known in the art. U.S. Patent No. 4,808,614, for example, describes gemeitabine hydrochloride, compositions containing gemeitabine hydrochloride and its use in the treatment of herpes viral infections. It also describes a process for the preparation of gemcitabine hydrochloride. The process describes the use of hydrolysis reagents such slightly acidic ion exchange comoresins for converting the compound of Formula III into the compound of Formula IV of the present invention.

US Patent No. 5,223,608 describes a process for the preparation of gemcitabine hydrochloride using hydrolysis agents such as strong acids in the preparation of 2-deoxy-2,2-difluoro-D-erythro-pentofurans-3-dibenzoate. 1-ulosis.

International Application Publication No. WO12005 / 095430 A1 describes a process for the preparation of gemcitabine hydrochloride. This application describes the use of hydrolysis reagents as strong acids for the preparation of 2-deoxy-2,2-difluoro-D-erythro-pentofurans-1-ulose 3,5-dibenzoate and the process of their purification. This also describes a process for the purification of gemcitabine hydrochloride by dissolving 95% beneficiated gemcitabine β-anomer hydrochloride in isolated water using solvents such as isopropyl alcohol or acetonitrile or acetone.

The above approaches employ slightly acidic and strong acid deion exchange resins as the hydrolysis agents during the formation of unprotected or protected lactone. Both types of hydrolysis agents suffer from the disadvantage of lactone ring formation, undesirable shredding products, impurities and often a lactonareverte to their open chain precursor due to their sensitivity to strong acids and resins.

US Patent No. 5,945,547 describes a process for purifying gemcitabine hydrochloride to its anomeric impurity comprising dissolving an anomeric α / β mixture 1: 1 in hot water, followed by the addition of refluxing acetone, and cooling. solution to a temperature of approximately -10 to 50 ° C. Precipitated precipitated gemcitabine hydrochloride was subjected to further purification by repeating the above process to obtain purified J3-anomeric gemcitabine hydrochloride.

International Application Publication No. WO2006 / 095359 describes a process for the preparation of gemcitabine hydrochloride. This application describes a process for the preparation of gemcitabine using a protecting group such as p-chlorine or p-methyl or p-nitrobenzoyl. This application also describes a process for the purification of gemcitabine hydrochloride by reducing the β-anomer paste. 95% gemcitabine hydrochloride in water then formed a solid with acetone. Gemcitabine hydrochloride was further purified with water and acetone or acetonitrile or isopropanol to obtain 99.9% degemcitabine hydrochloride.

International Application Publication No..2006 / 092808 describes a process for the purification of gemcitabine hydrochloride using recrystallization with water and acetic acid to obtain 99.94% of the β-anomer from the original 95% of the β-anomer.

The present invention relates to a process for intermediate preparation, and improvements in purification techniques to produce degemcitabine hydrochloride β-anomer substantially free of the α-anomer. According to the present invention a convenient process for the preparation of degemcitabine hydrochloride is proposed. of its intermediates with a desired degree of purity and desired yield using better preparation techniques which are simple, environmentally friendly, economical, robust and well suited for industrial scale use.

SUMMARY OF THE INVENTION

The present invention proposes a process for preparing gemcitabine hydrochloride and its intermediates.

In one aspect, the present invention proposes a process for the preparation of gemcitabine or a salt thereof comprising:

(i) the conversion of ethyl 2-difluoro-3-hydroxy-3- (2,2-dimyldioxalan-4-yl) propionate to Formula 2-deoxy-2,2-difluoro-1-oxoribose using sodium hydroxide and a lower alcohol solvent, followed by azeotropic distillation;

(ii) protecting the hydroxy groups of the compound of Formula IV using tert-butyl diphenyl silyl chloride as a hydroxy protective reagent to give 3,5-bis (tert-butyl diphenyl silyloxy) -2-deoxy-2; 2-Difluoro-1-oxoribose of Formula V:

iii) reducing the compound of formula V using a suitable reducing reagent to give 3,5-bis (tert-butyl diphenyl silyloxy) -2-deoxy-2,2-difluoro ribose of Formula VI;

(iv) protecting the compound of Formula VI using an alkyl or aryl sulfonyl chloride in the presence of a suitable base to provide 3,5-bis (tert-butyl diphenyl silyloxy) -1-methanesulfonyloxy 2-deoxy-2,2-difluoro ribose of Formula VII;

v) condensing the compound of Formula VII with the N-acetylcytosine compound of Formula VIII in the presence of a suitable base to result in 1- [2'-deoxy-2 ', 2'-difluoro-3', 5'-ribofuranose- 3,5-bis (tert-butyl diphenylsilyloxy) cytokine of Formula IX; and

vi) deprotecting the compound of Formula IX using a suitable reagent to obtain gemcitabine, which may subsequently be converted to the acid addition salt by reacting with an acid.

In another aspect the present invention relates to a process for the purification of gemcitabine hydrochloride to obtain gemcitabine hydrochloride benefited with its β-anomer.

In another embodiment, a process for purifying gemcitabine hydrochloride comprises:

a) providing a solution of degemcitabine hydrochloride in an aqueous solvent;

b) increasing the concentration of degemcitabine hydrochloride in the solution to produce a precipitation;

c) isolating the benefited compound with β-anomer.

One embodiment of the present invention proposes a process for preparing gemcitabine or a salt thereof comprising reacting a compound having Formula IV:

<formula> formula see original document page 6 </formula> with t-butyldiphenylsilyl chloride to form a compound having Formula V

<formula> formula see original document page 7 </formula>

Another embodiment of the present invention proposes a compound having a formula:

<formula> formula see original document page 7 </formula>

Another embodiment of the present invention proposes a compound having the formula:

<formula> formula see original document page 7 </formula>

where "OMs" represents a methane sulfonyl group

Another embodiment of the present invention proposes a compound having the formula

<formula> formula see original document page 7 </formula> BRIEF DESCRIPTION OF THE DRAWINGS

Figure 1 is an X-ray powder diffraction (XRPD) pattern of gemcitabine hydrochloride prepared according to Example 10.

Figure 2 is a differential scanning calorimetry (DSC) curve of gemcitabine hydrochloride prepared according to Example 10.

Figure 3 is a non-infrared (IR) absorption spectrum of gemcitabine hydrochloride prepared according to Example 10.

Figure 4 is a thermogravimetric curve (TGA) gemcitabine hydrochloride prepared according to Example 10.

Figure 5 is an HPLC chromatogram of degemcitabine hydrochloride prepared according to Example 10.

Figure 6 is a schematic representation of a process for preparing gemcitabine hydrochloride.

DETAILED DESCRIPTION OF THE INVENTION

The present invention relates generally to a process for the preparation of gemcitabine hydrochloride and its intermediates.

In one aspect, the present invention proposes a process for the preparation of gemcitabine or a salt thereof, comprising:

i) the conversion of 2,2-difluoro-3-hydroxy-3- (2,2-dimethyldioxalan-4-yl) propionate of Formula III to 2-deoxy-2,2-difluoro-1-oxoribose of Formula IV using -siode and a lower alcohol solvent, followed by an azeotropic distillation; <formula> formula see original document page 9 </formula>

(ii) protecting the hydroxyl groups of the compound of Formula IV using tert-butyl diphenyl silyl chloride as a hydroxy protective reagent to give 3,5-bis (tert-butyl diphenyl silyloxy) -2-deoxy-2; 2-Difluoro-1-oxoribose of Formula V:

<formula> formula see original document page 9 </formula>

Formula V

iii) reducing the compound of formula V using a suitable reducing reagent to give 3,5-bis (tert-butyl diphenyl silyloxy) -2-deoxy-2,2-difluoro ribose of Formula VI;

<formula> formula see original document page 9 </formula>

Formula Vl

iv) protecting the compound of Formula VI using an alkyl or aryl sulfonyl chloride in the presence of a suitable base to provide 3,5-bis (tert-butyl diphenylsilyloxy) -1-methanesulfonyloxy-2 deoxy-2,2-difluoro ribose of Formula VII;

<formula> formula see original document page 10 </formula>

wherein "OMs" represented a yrupu nickel sulfonyl;

v) condensation of the compound of Formula VII with the N-acetylcytosine compound of Formula VIII in the presence of a suitable base to give 1- [2'-deoxy-2 ', 2'-difluoro-3', 5'-ribofuranose- 3,5-bis (tert-butyl diphenylsilyloxy) cytokine of Formula IX; and

<formula> formula see original document page 10 </formula>

vi) deprotecting the compound of Formula IX using a suitable reagent to obtain gemeitabine, which may subsequently be converted to the acid addition salt by reacting with an acid.

Step i) involves converting the 2-difluoro-3-hydroxy-3- (2,2-dimethyldioxalan-4-yl) compostopropionate of Formula III to 2-deoxy-2,2-difluoro-1-oxoribose of Formula IV, using iodine and a lower alcohol solvent, followed by azeotropic distillation.

Lower alcohol solvents which may be used in the process of step i) have from 1 to about 6 straight or branched carbon atoms and include similar methanol, ethanol, n-propanol, isopropanol, n-butanol.

Suitable solvents that may be used for reaction include solvents of lower (C1-C6) alcohols, hydrocarbons such as toluene and the like.

Suitable temperatures for conducting the reaction range from about 200 ° C to about 70 ° C.

After completion the reaction mixture is quenched with water and sodium thiosulfate. A water immiscible solvent is added to the reaction mixture and azeotroped to remove water and methanol. The distillation may be conducted at temperatures of approximately 50 ° C and approximately 150 ° C.

Water immiscible solvents that may be used include halogenated hydrocarbons and hydrocarbons such as n-hexane, cyclohexane, n-heptane, toluene, chlorobenzene, 1,2-dichlorobenzene, similar xylenes.

The reaction mixture comprising the product may be used directly in the subsequent reaction step or suitably may be concentrated to obtain a residue.

Step ii) involves the protection of the compound hydroxide groups of Formula IV using tert-butyldiphenyl silyl chloride as the hydroxy protective reagent in the presence of a suitable base to provide 3,5-bis (tert-butyl diphenyl silyloxy). ) -2-Deoxy-2,2-difluoro-1-oxoriboside Formula V. Suitable alternative hydroxy protecting groups which may also be used in the above reaction include, without limitation, hydroxide protecting silyl groups such as tert-butyldiphenylsilyl, trimethylsilyl chloride , isopropyldimethylsilyl, methyldiisopropyl silyl, triisopropyl silyl and the like, formyl, 2-chloroacetyl, benzyl, diphenylmethyl, triphenylmethyl, 4-nitrobenzyl, phenoxycarbonyl, t-butyl, methoxymethyl, phenoxyacetyl, isobutyryl, benzoyloxy -carbonyl and similar.

Suitable bases which may be used include, without limitation, organic bases such as pyridine, triethylamine, imidazole, 2,6-lutidine, 2,3-lutidine, 3,5-lutidine and the like.

Suitable solvents that may be used in the process of step ii) include, without limitation: ethers such as tetrahydrofuran, 1,4-dioxane, diethyl ether, 1,2-dimethoxy ethane and the like; hydrocarbons such as n-hexane, cyclohexane, n-heptane, toluene, similar xylenes; halogenated hydrocarbons such as chlorobenzene, 12-dichlorobenzene and the like; aprotic polar solvents such as α, β-dimethyl formamide (DMF), dimethyl sulfoxide dimethyl acetamide, similar acetonitrile; ketones such as acetone, methyl isobutyl ketone, methyl tert-butyl ketone and the like; and their mixtures.

Suitable temperatures for conducting the reaction range from about 5 ° C to about 50 ° C.

Step iii) involves reducing the compound of Formula V using a reducing reagent suitable to obtain 3,5-bis (tert-butyl diphenylsilyloxy) -2-deoxy-2,2-difluoribose of Formula VI.

Suitable reducing reagents which may be used include, without limitation, sodium bis (2-methoxy-ethoxy) aluminum hydride (Vitride), sodium boride (NaBH4), lithium aluminum hydride (LiAlH4), diisobutyl aluminum hydride (DIBAL-H) and the like.

Suitable solvents that may be used include, without limitation: ethers such as tetrahydrofuran, 1,4-dioxane, diethyl ether, 1,2-dimethoxy ethane and the like hydrocarbons such as n-hexane, cyclohexane, n-heptane, toluene, xylenes and the like; halogenated hydrocarbons such as chlorobenzene, 1,2-dichlorobenzene and the like; your mixtures.

Suitable temperatures for conducting the reaction range from about -600 ° C to about 100 ° C.

Step iv) involves protecting the compound of Formula VI using an alkyl or arylsulfonyl chloride in the presence of a suitable base to provide 3,5-bis (tert-butyl diphenylsilyloxy) -1-methanesulfonyloxy 2-Deoxy-2,2-difluoro ribose of Formula VII.

Suitable protecting groups which may be used for the protection of the hydroxy group include, without limitation, alkyl and aryl sulfonyl chlorides such as methane sulfonyl chloride, benzene sulfonyl chloride and the like.

In one embodiment of the present invention, the protecting group used for the protection of the compound VI hydroxyl group of Formula VI is methanesulfonyl chloride in the presence of base to obtain the compound of Formula VII. Suitable bases which may be used include, without limitation, organic bases. such as pyridine, triethylamine, diethyl amine and the like.

Suitable solvents which may be used for aeration above include, without limitation: ethers such as tetrahydrofuran, 1,4-dioxane, diethyl ether and 1,2-dimethoxyethane and the like; hydrocarbons such as n-hexane, cyclohexane, n-heptane, toluene, similar xylenes; halogenated hydrocarbons such as chlorobenzene, 1,2-dichlorobenzene, and the like; aprotic polar solvents such as α, β-dimethyl formamide (DMF), dimethyl sulfoxide, dimethyl acetamide, acetonitrile and the like; esters such as ethyl acetate, deisopropyl acetate, and the like; ketones such as acetone, methyl isobutyl ketone, methyl tert-butyl ketone and the like; your mixtures.

Suitable temperatures for conducting the reaction range from about 0 ° C to about 50 ° C.

Step v) involves condensation of the compound of Formula VII with the acetylcytosine compound of formula VII in the presence of a suitable base to give 1- [2'-deoxy-2 ', 2'-difluoro-3', 5'-ribofuranose -3,5-bis (tert-butyl diphenyl silyloxy) cytokine of Formula IX.

Suitable solvents which may be used above include, without limitation: ethers such as tetrahydrofuran, 1,4-dioxane, diethyl ether, 1,2-dimethoxyethane and the like; hydrocarbons such as n-hexane, cyclohexane, n-heptane, toluene, xylenes and the like halogenated hydrocarbons such as chlorobenzene, 1,2-dichlorobenzene and the like; esters such as ethyl acetate, isopropyl acetate and the like; ketones such as acetone, methyl isobutyl ketone, methyl tert-butyl ketone and the like; and their mixtures.

Suitable bases which may be used include, without limitation, organic bases such as pyridine, triethylamine, hexamethyldisilazane, detrimethylsilyl triflate and the like and combinations thereof.

Suitable temperatures for conducting the reaction range from about 20 ° C to about 120 ° C.

Optionally, the 1- [2'-deoxy-2 ', 2'-difluoro-3', 5'-ribofuranose-3,5-bis (tert-butyldiphenylsilyloxy) N-acetyl cytokine of (Formula VIIIa) is not isolated. Figure 6) forming as an intermediate. When using this option, the reaction mixture containing this compound is passed directly to the next step.

Step vi) involves deprotecting the compound of formula IX using a suitable reagent to obtain eitabine, which can subsequently be converted to an acid addition salt by reacting with an acid.

Suitable deprotection reagents which may be used include ammonium fluoride, tert-butylammonium fluoride, ammonia, acetyl chloride, hydrochloric acid and the like.

Solvents used in the above reactions include limitless: water; alcohols such as methanol, ethanol, ethanol hydrochloride, n-propanol, isopropanol, alcohol propyl alcohol, n-butanol and the like; halogenated solvents such as dichloromethane, dichloroethane, chloroform, chlorobenzene, 1,2-dichlorobenzene and the like; ethers such as tetrahydrofuran, 1,4-dioxane, diethyl ether, 1,2-dimethoxy ethane and the like hydrocarbons such as n-hexane, cyclohexane, n-heptane, toluene, xylenes and the like; aprotic-polar polar solvents such as N, N-dimethylformamide (DMF) dimethyl sulfoxide, dimethyl acetamide, acetonitrile and the like; esters such as ethyl acetate, isopropyl acetate and the like: ketones such as acetone, methyl isobutyl ketone, methyl tert-butyl ketone and the like; and their mixtures.

Suitable temperatures for conducting the reaction range from about -10 ° C to about 70 ° C.

The obtained gemcitabine base can be converted into a pharmaceutically acceptable desired acid addition salt by reacting it with a suitable acid.

Suitable pharmaceutically acceptable acids which may be used include, without limitation, inorganic acids such as hydrochloric acid, hydrobromic acid and hydroiodic acid; and organic acids such as acetic acid, tartaric acid, oxalic acid and the like.

Optionally, one or more steps i) to iv) are consequently conducted in isolating the intermediate compounds. In one embodiment of the invention, step i) is conducted without isolating the intermediate, followed by isolation of the compound of Formula V.

Optionally, the wet cake obtained at various stages of the process may be further dried. Drying can be properly conducted in a tray dryer, vacuum oven, air oven, fluidized bed dryer, rotary flash dryer, flash dryer, and the like. Drying may be conducted for any desired period of time to achieve the desired degree of purity such as from about 1 to 20 hours or more.

The whole process is represented schematically in Figure 6.

In another aspect, the present invention relates to a process for the purification of degemcitabine hydrochloride to produce gemcitabine hydrochloride benefited with its β-anomer.

One embodiment of the process for purifying gemcitabine hydrochloride comprises:

a) providing a solution of degemcitabine hydrochloride in an aqueous solvent;

b) increasing the concentration of degemcitabine hydrochloride in the solution to produce a precipitation; and

c) isolating the J3-anomer-benefited compound.

Step a) involves providing a gemcitabine hydrochloride solution in an aqueous solvent.

Gemcitabine hydrochloride solution is obtained by dissolving it in water or it can be obtained from an earlier processing step in which gemcitabine hydrochloride is formed. Any form of degemcitabine hydrochloride is acceptable for solution formation, as is any crystalline or amorphous form of degemcitabine hydrochloride.

Gemcitabine hydrochloride for dissolution purposes may be prepared by known methods in the art or by the processes mentioned above.

The concentration of the anomeric salt mixture in the solution is not critical as long as sufficient water is employed to ensure complete dissolution. The amount of water employed is generally kept low to avoid excessive product loss through crystallization and insulation. The amount of water used for β-anomer isolation is often about 1 to about 12 times the weight of gemcitabine hydrochloride.

The solution may be prepared at temperatures which would be from about 0 ° C to about 100 ° C. Depending on the amount of solvent taken, it may dissolve at 25 to 100 ° C, or the solution may need to be heated at elevated temperatures of about 50 ° C to 100 ° C. ° C.

The solution may optionally be treated with activated carbon to accentuate the color of the compound, followed by filtration by means such as through a calcined diatomaceous earth fluid (Hyflow) bed to remove carbon.

The preferred amount of carbon carbon used in the isolation of the better color β-anomer is approximately 0.1 to approximately 10 times the weight of the α / β anomer mixture.

Carbon treatment may be conducted either at dissolution temperatures or after the solution has cooled to lower temperatures.

Step b) involves increasing the concentration of gemcitabine hydrochloride in the solution to produce a precipitate.

The concentration may be suitably conducted by using evaporative atmospheric distillation or vacuum distillation.

Distillation of the solvent may be conducted at a vacuum of approximately 100 mmHg (13.33 kPa) to approximately 720 mmHg (95.99 kPa) at temperatures of approximately 400 ° C to approximately 70 ° C. Any temperature and vacuum conditions may be used as long as concentration occurs without an increase in impurity levels.

Concentration of the solution may be conducted to such an extent that precipitation of gemcitabine hydrochloride begins with solution, converting the solution to a paste. Generally the concentration will be terminated when the solvent to gemcitabine hydrochloride ratio becomes approximately 1: 1 and approximately 1: 5.

The reaction mixture may be further maintained at lower temperatures than the concentration temperatures, such as, for example, below approximately 40 ° C to approximately 450 ° C for a period of time that may be required during more complete isolation of the product. The exact cooling temperature and time required to complete the crystallization can be readily determined by those skilled in the art and will also depend on the parameters such as the concentration and temperature of the solution or paste.

Step c) involves the isolation of the compound benefited with the β-anomer.

The isolation of the solid may be conducted by techniques such as filtration, decantation, centrifugation or the like, or by filtration under an atmosphere by inerting gases such as, for example, similar nitrogen.

The wet cake obtained in step c) may optionally be further dried. Drying may suitably be conducted in a tray dryer, vacuum oven, air oven, fluidized bed dryer, flash dryer, flash dryer and the like. Drying can be conducted at temperatures from about 35 ° C to about 10 ° C. Drying may be conducted for any length of time necessary to achieve a desired degree of purity, such as approximately 1 to 20 hours or more.

In a specific embodiment of the invention, the process described above of the invention may be adapted to form the basis of a continuous crystallization process. The purity of the product obtained in step c) is checked to see the percentage of α-anomer impurities. If the purity has not been reduced to the desired levels below 0.1% as determined by high performance liquid chromatography (HPLC), then steps a) to c) are repeated with the wet material obtained in step c). When the desired degree of purity is reached in step c), the cycle is interrupted.

Therefore, a cycle of operations is established which can be repeated indefinitely, thereby adapting the process of the invention to a continuous process with the obvious advantages associated with commercial scale.

The purified gemcitabine hydrochloride obtained above contains less than 0.1%, or less than 0.01%, of either decytosine impurity or α-anomer.

Gemcitabine hydrochloride obtained by the above process was analyzed using HPLC according to the procedure described in United States Pharmacopeia, 29: NF 24, 2005 (USP), pages 990-991, as described in Table 1.

Table 1: HPLC Method

<table> table see original document page 21 </column> </row> <table> <table> table see original document page 22 </column> </row> <table>

Relative retention time ("RRT") values for impurities are relative to gemcitabine time when a value of 1 is assigned.

The crystalline gemcitabine hydrochloride obtained by the process of the present invention is characterized by its X-ray powder diffraction pattern ("XRPD"), differential scanning decalorimetry ("DSC") curve and / or infrared ("IR") absorption spectrometer .

The crystalline gemcitabine hydrochloride obtained in the present invention is characterized by its XRPD standard. All the XRPD data reported herein were obtained by using the Ka Ka radiation of wavelength of 1.541 Å and were obtained using a diffractometer of X-rays Bruker Ax D8 Advance Powder X-ray Diffractometer.

Crystalline gemcitabine hydrochloride is characterized by an XRPD diffraction pattern substantially according to Figure 1, having peaks characteristic at approximately 9.6, 11.4, 13.7, 19.1,22.9, 24.0, 26.6 , and 30.7 ± 0.2 degrees 2 theta.

Differential scanning calorimetric analysis was conducted on a TA Instruments DSC Q 1000 model with a ramp of 5 ° C / min with a modulation time of 60 seconds and a modulation temperature of ± 1 ° C. The starting temperature was 0 ° C and the final temperature was 200 ° C.

Crystalline gemcitabine hydrochloride has a differential scanning calorimetry curve characteristic substantially of Figure 2, having an endothermic peak at 259-274 ° C.

The infrared (IR) absorption spectrum of gemcitabine hydrochloride was recorded on a Perkin Elmer System model Spectrum 1 spectrophotometer, between 450 cm -1 and 4,000 cm -1, with a resolution of 4 cm -1 in a potassium bromide granule. with the test compound at a concentration of 1% by mass.

Crystalline gemcitabine hydrochloride is characterized by an IR spectrum substantially as in Figure 2. Crystalline gemcitabine hydrochloride is characterized by an IR spectrum with characteristic peaks approximately 3392, 3259, 3117, 3078, 1679, 1535, 1283,1199, 1065, 856 and 814 ± 5 cm -1.

In yet another aspect, the present invention provides for substantially residual solvent free gemcitabine hydrochloride.

Gemcitabine hydrochloride obtained using the process of the present invention has an amount of residual solvent content which is within the limits given by the International Conference on Harmonization of Technical Requirements for Registration of Human Use ("ICH") guidelines. The solvent level according to the guidelines depends on the type of solvent, but is not higher than approximately 5000 ppm, or approximately 4000 ppm or approximately 3000 ppm.

Gemcitabine hydrochloride obtained in the present invention contains: less than approximately 100 ppm, or less than approximately 500 ppm acetone; less than approximately 100 ppm, or less than approximately 500 ppm, of isopropanol; and less than approximately 100 ppm or less than approximately 500 ppm dichloromethane.

The dried product may optionally be ground to the required particle size. Crushing or micronization may be conducted before drying, or after the product has been completely dried. Crushing operation reduces particle size and increases the surface area of the particles by causing the particles to solidify together at high speeds.

In one embodiment, gemcitabine hydrochloride obtained by the process of the present invention has a particle size distribution of: D90 below about 600 μm, or approximately 400 μτη, or approximately 300 μm; D50 below approximately 400pm, or approximately 300 pm, or below 300 pm; eD10 below 200 pm, or approximately 100 pm, or approximately 50 pm.

The D0, D50 and D90 values are useful means for indicating a particle size distribution. D90 is the value for the protein size for which at least 90 percent of the particle volume is smaller than the given value. Likewise D50 and D10 refer to the values for the particle size for which 5C volume percent and 10 volume percent, respectively, of the particle size are smaller than the given value.

Methods for determining D10, D50 and D90 include laser light diffraction using equipment such as Malvern Instruments Ltd (Malvern, Worcestershire, United Kingdom). There is no specific lower limit for any of the D values. Certain specific aspects and embodiments of the present invention will be explained in more detail with reference to the following examples, which are given by way of illustration only and should not be construed as absolutely limiting. the scope of the invention.

EXAMPLE 1: PREPARATION OF 3,5-BIS (TERC-BUTYL DIFENYL SILILOXY) -2-DEOXY-2,2-DIFLUOR-1-OXORRIBOSE (FORMULAV)

A clean, dry round-bottomed flask was charged with 100 g of Formula III ethyl 2,2-difluoro-3-hydroxy-3- (2,2-dimethyldioxalan-4-yl) propionate, 1000 mL of methanol and 10 g of iodine, then stirring overnight at 27 ° C. A 10% aqueous sodium diosulfate solution (22.5 g of sodium thiosulfate dissolved in 225 mL of water) was added to the above reaction mixture at about 27 ° C for approximately 30 minutes and then distilled off. solvent of the reaction mixture at approximately 80 ° C. Subsequently, the reaction mixture obtained was charged with 500 ml of toluene, then distilled off at atmospheric pressure at 95 ° C. The above step was repeated 5 times until the boiling point of the reaction mixture reached 100 ° C. The reaction mixture was then distilled at a vacuum of 650 mmHg (86.66 kPa) at 50 ° C to give the 2-deoxy-2,2-difluoro-1-oxoriboside compound of Formula IV as residue.

The residue obtained from the above reaction was dissolved in 1320 mL of α, β-dimethyl formamide (DMF) under a denitrogen atmosphere at approximately 27 ° C. The above reaction mixture was charged with 80.3 g of imidazole and 300 ml of tert-butyldiphenylsilyl chloride (TBDPSi-CI) at 27 ° C, and stirred overnight at 27 ° C. The termination of the reaction was verified using layered chromatography (TLC) and the reaction mixture was cooled to 15 ° C.

2600 mL of water were added at 27 ° C, stirring simultaneously and then extracted with 2 x 1000 mL of petroleum ether. The aqueous and aqueous phases were separated and the organic phase was then washed with 3 x 1000mL of water and the organic phase was completely distilled at 48 ° C under vacuum. The obtained residue was purified by column chromatography using petroleum ether and ethyl acetate solvent systems to give 212.7 g of the title compound having 93.49% purity by HPLC.

1H-NMR (400 MHz, DMSO-d6, δ in ppm): 0.8 (9H), 1.1 (9H), 4.5 (2H), 3.4 (1H), 3.7 (9H).

MASS: m / z 662.4 (M + NH 4).

EXAMPLE 2: PREPARATION OF 3,5-BIS (TERC-BUTYLDIFENYL SILILoxy) -2-DEOXY-2,2-DIFLUORRIBOSE (FORMULA VI)

A round bottom flask with 243 g of 3,5-bis (tert-butyl diphenyl silyloxy) -2-deoxy-2,2-difluoro-1-oxoribose of Formula V and 240 mL of tetrahydrofuran (THF) was charged. under a nitrogen atmosphere at approximately 270 ° C while stirring simultaneously. The deration mixture was cooled to -45 ° C and 192 ml of bis (2-methoxyethoxy) aluminum hydride desodium (Vitride) was added to the deration mixture. The reaction mixture obtained was stirred for approximately 1 hour, 45 minutes and tested by thin layer chromatography to confirm termination of the reaction. After completion of the reaction, the resulting reaction solution above was charged with 486 mL of ammonium chloride saturated solution at approximately -450 ° C and raised to temperature to 100 ° C. The suspension obtained was filtered and the aqueous phase from the filtrate was extracted with 1215 mL of ethyl acetate and 486 mL of brine solution, then separating the organic and aqueous phases.

The aqueous phase was charged with 1215 mL of ethyl acetate and the organic and aqueous phase was separated. Finally the total organic phase was completely vacuum distilled to give 245 g of the title compound.

1H-NMR (400 MHz, DMS0-d6.0 in ppm): 0.9 (9H), 1.1 (9H), 5.1 (1H)

PASTA: m / z 664.4 (M + NH 4)

EXAMPLE 3: PREPARATION OF 3,5-BIS (TERC-BUTYLDIFENYL SILILOX-1 METHANE SULPHONYLOXY-2-DEOXY-2,2-DIFLUORRIBOSIS (FORMULA VII)

A round bottom flask containing 245 g of 3,5-bis (tert-butyl diphenyl silyloxy) -2-deoxy-2,2-difluoribose of Formula VI and 2450 mL of dichloromethane under a nitrogen atmosphere was charged under stirring. simultaneously. The reaction mixture was cooled to 0 ° C and 55.5 mL of triethylamine and the above reaction mixture was charged with 18.6 mL of methanesulfonyl chloride above. The temperature of the reaction mixture was allowed to rise to 270 ° C and stirred for approximately 2.5 hours. The reaction was terminated using thin layer chromatography.

The resulting reaction mixture above was charged with 1225mL of water and the two phases separated. The resulting organic phase was completely distilled at 45 ° C under vacuum to give a gummy solid. The gummy solid obtained above was charged with petroleum ether and cooled to 2 ° C. The obtained suspension was stirred for 3 hours and the solid filtered, then dried by suction to give 191 g of the title compound.

1H-NMR (400 MHz, DMSO-d6, δ in ppm): 5.9 (1H), 0.8 (9H), 1.1 (9H), 3.1 (3H).

MASS: m / z 742.2 (M + NH 4).

EXAMPLE 4: PREPARATION OF 1- [2'-DEOXY-2 ', 2'-DIFLUOR-3', 5'-RIBOPHURANOSE-3,5-BIS (TERC-BUTYL DIPHYLYLYLXY) CYTOKINE (FORMULA IX)

A 89 g N-acetyl cytosine round bottom flask was charged under a nitrogen atmosphere. 525 ml hexamethyl disilazane (HMDS) was added to the above flask at 27 ° C. 18.5 mL of detrimethyl silyl chloride was added to the above reaction mixture and 132 mL of trimethylsilyl detriflate (TMS triflate). The above reaction mixture was charged with 105 g of the mesylate compound of Formula VII and the reaction mixture was heated to 93 ° C while stirring for 3 hours at 93 ° C. The reaction mixture was cooled to approximately 35 ° C and 500 mL of dichloromethane was charged. The reaction solution obtained was added to cold water at 90 ° C over a period of 40 minutes. The suspension obtained was filtered and the wet cake was washed with dichloromethane (210 mL). The aqueous aqueous phases were separated from the filtrate obtained and the aqueous phase was extracted with dichloromethane (500 mL). Finally the organic phases were combined and the organic phase was washed with 2 x 500 mL of water. The total organic phase was completely distilled at 44 ° C under a vacuum of 600 mmHg (79.99 kPa) to give 105 g of the title compound.

EXAMPLE 5: PREPARATION OF GEMCITABINE105 g of 1- [2'-deoxy-2,2'-difluoro-3 ', 5'-ribofuranose-3,5-bis (tert-butyl diphenyl silyloxy) -cytocin Formula IX, which was prepared in Example 4 was dissolved in 1500 mL of methanol. Ammonium fluoride (72 g) was added to the reaction solution and then heated to 65 ° C (reflux). The reaction mixture was refluxed for approximately 3 hours to complete sanding, and the solvent was then distilled at 48 ° C in a vacuum of 600 mm Hg. The residue was charged with 500 ml of alcohol propyl alcohol and cooled to 5 ° C, then kept for 10 minutes at 5 ° C. The obtained reaction mixture was filtered and the solid washed with 200 mL of alcohol propyl alcohol. The filtrate obtained was completely distilled, then the residue was taken up in 500 mL of water and 500 mL of dichloromethane and the organic and aqueous phases were separated. The obtained aqueous phase was washed with 2 x 500 mL dichloromethane. 4 g of charcoal was added to the aqueous solution obtained and stirred for 20 minutes, then filtered through a Hyflow bed and the bed was washed with 50 ml of water. The filtrate obtained was completely concentrated in vacuo at 47 ° C to give 27 g of the title compound of 96.16% purity (a: 62.05%, β: 34.11%).

EXAMPLE 6: PREPARATION OF GEMCITABINATE CHLORIDE FORMULA I

A round bottom flask with 75 mL isopropyl alcohol and 25 g gemcitabine base obtained in Example 5 was charged, then the isopropyl alcohol solvent distilled off at a vacuum of 600 mmHg (79.99 kPa) at 47 ° C. The above step was repeated twice more. The residue obtained was again charged with 75 mL of alcohol propyl alcohol and heated to 60 ° C. 10 ml of 36% hydrochloric acid in aqueous solution were added to the above solution, then allowed to cool to 27 ° C. The reaction suspension was cooled again to -40 ° C and stirred for 6.5 hours at -4 ° C. Ç. The obtained solid suspension was filtered and the wet solid was washed with 75 mL of acetone. The solid was dried at 390 ° C under vacuum for 3 hours to give 9.4 g of the title compound.

HPLC purity: 98.5% (a: 11.19%, β: 87.31%).

EXAMPLE 7: RECRISTALIZATION OF DEGEMCITABIN CHLORIDRATE

A round bottom flask with gemeitabine hydrochloride 0.5 g and 1.5 mL of water was charged and the reaction mixture stirred for 6 hours at 27 ° C. The reaction suspension was then filtered and the solid was washed with 2mL of acetone, then dried for 3 hours at 40 ° C to give 0.37 g of the title compound.

HPLC purity: 99.81% β-anomer% a-anomer: 0.05%.

EXAMPLE 8: GEMCITABINE CHLORIDRATE PURIFICATION

A reactor was charged with 26.4 L (3 volumes) of demineralized water, and heated to approximately 82 ° C. To the above reactor was added 6.6 kg of degemeitabine hydrochloride crude anomeric salt mixture having an α: β ratio of approximately 1: 1 by HPLC while stirring until a clear solution formed. The reaction solution was cooled to approximately 23 ° C, then the separated solid was filtered under a nitrogen atmosphere and the solid was washed with 5 L of acetone. The resulting solid was suction dried for approximately 1 hour at nitrogen pressure to give 2.7 kg gemcitabine hydrochloride.

HPLC purity: 98.1%; α-anomer: 1.7%.

EXAMPLE 9: GEMCITABINE CHLORIDRATE PURIFICATION

A reactor with 860 mL (10 volumes) of purified water was charged, along with 86 g of gemcitabine hydrochloride anomeric crude mixture having an a: J3 ratio of approximately 1: 1. The mixture was heated to a temperature of approximately 38 ° C while stirring to form a clear solution.

0.1 volume of carbon of carbon was added to the stirring mixture at 38 ° C, stirring for approximately 30 minutes. The reaction mixture was filtered through Hyfow, then washed with 3 x 30 mL of demineralized water at room temperature. The filtrate obtained was concentrated to 3 volumes of the reaction mixture at 460 ° C in a vacuum of 600 mm Hg, then cooled to 17 ° C while stirring for approximately 30 minutes at 18 ° C. The reaction mixture was filtered, then washed with 50 mL of acetone at 160 ° C and suction dried for 30 minutes. The solid obtained was dried at a temperature of approximately 400 ° C for approximately 4 hours in vacuo 600 mmHg (79.99 kPa) to give 31 g gemcitabine hydrochloride. HPLC purity: 95.6%; α-anomer: 6.8%.

EXAMPLE 10: DEGEMCITABIN CHLORIDRATE PURIFICATION

A reactor with 342 mL (12 volumes) of purified water was charged, along with 28.5 g of degemcitabine hydrochloride having a purity of 95.6%, and heated to a temperature of approximately 37 ° C while stirring. simultaneously to form a transparent solution.

0.1 volume of charcoal was added to the reaction mixture at 37 ° C with stirring for approximately 30 minutes. The reaction mixture was filtered through a Hyflow bed, then washed with 3 χ 25 mL of demineralized water at room temperature. The obtained filtrate was concentrated to 2 volumes of the reaction mixture at 470 ° C at a vacuum of 600mmHg (79.99 kPa). and then cooled to 30 ° C. The reaction suspension was filtered, then washed with 31 mL of deacetone at 27 ° C. The above process was repeated once and the solid obtained was dried at a temperature of 40 ° C for approximately 4 hours at a vacuum of 600 mmHg (79.99 kPa) to give 24 g of gemcitabine hydrochloride.

HPLC purity: 99.96%; α-anomer: 0.01%.

Optical rotation: [α] D20 (10 mg / mL aqueous solution): + 47.1 °.

Claims (18)

Process for the preparation of gemcitabine or a salt thereof, characterized in that it is understood that a compound having Formula IV is reacted: <formula> formula see original document page 33 </formula> with t-butyldiphenylsilyl chloride to form a compound having Formula V: <formula> formula see original document page 33 </formula> Process according to Claim 1, characterized in that a compound of Formula IV is prepared by reacting a compound having Formula III: iodine. in an alcoholic solvent. Process according to Claim 1, characterized in that it further comprises reacting a compound having Formula V with a reducing reagent to form a compound having Formula VI: <formula> formula see original document page 34 </formula> Formula Vl. Process according to Claim 3, characterized in that it further comprises the compound of Formula VI with demethane sulfonyl chloride to be formed to form a compound of Formula VII: <formula> formula see original document page 34 wherein "OMs" represents a methane sulfonyl group. Process according to Claim 4, characterized in that it further comprises condensing the compound of Formula VII with N-acetylcytosine to form a compound of FormulaIX: <formula> formula see original document page 34 </ formula> Process according to Claim 5, characterized in that a compound having Formula VIIIa: <formula> formula see original document page 35 </formula> Formula Villa is formed during condensation but is not isolated. Process according to Claim 5, characterized in that it further comprises the protection of a compound having Formula IX to formagemcitabine. 8. Compound, CHARACTERIZED by the fact that it has a formula: <formula> formula see original document page 35 </formula> 9. A compound, characterized in that it has a formula: wherein "OMs" represents a methane sulfonyl group. 10. Compound, CHARACTERIZED by the fact that it has a formula: <formula> formula see original document page 36 </formula> 11. Process for beneficiation of a gemcitabine hydrochloride β-anomer, CHARACTERIZED by the fact that it comprises: a) providing a degemcitabine hydrochloride solution in an aqueous solvent, b) increasing the solute concentration in the solution to produce a precipitation c) isolating the gemcitabinabenefit hydrochloride with the {3-anomer. Process according to Claim 11, characterized in that the weight ratio of water to gemcitabine hydrochloride in the solution of a) ranges from approximately 3: 1 to approximately 12: 1. Process according to Claim 11, characterized in that the solution of a) is treated with activated carbon. Process according to Claim 11, characterized in that the increase in concentration comprises the removal of a portion of water. Process according to claim 11, characterized in that the increase in concentration is continued until a weight ratio of water for gemcitabine hydrochloride of less than approximately 3: 1 is reached. Process according to Claim 11, characterized in that the isolation of gemcitabine hydrochloride benefited with the β-anomer is conducted at a temperature of from about 0 ° C to about -10 ° C. Process according to Claim 11, characterized in that the {3-anomer-gemcitabine hydrochloride contains no less than approximately 99.7% of the β-anomer. Process according to Claim 11, characterized in that the β-anomer-benefited gemcitabin hydrochloride contains no less than approximately 99.9% of the β-anomer.