WO2009111162A1

WO2009111162A1 - Process for the preparation of 3-hydroxymorphinan derivatives

Info

Publication number: WO2009111162A1
Application number: PCT/US2009/034343
Authority: WO
Inventors: Peter X. Wang; Tao Jiang; Gary L. Cantrell; David W. Berberich; Frank W. Moser; Jian Bao
Original assignee: Mallinckrodt Inc.
Priority date: 2008-02-29
Filing date: 2009-02-18
Publication date: 2009-09-11
Also published as: US7999105B2; EP2319845B1; US20090221825A1; ATE519765T1; EP2250175A1; EP2250175B1; EP2319845A1; CA2716944A1

Abstract

Processes are described for the synthesis of 3-hydroxymorphinan derivatives by hydrolysis of side products from the O-demethylation of 3-methoxymorphinan derivatives.

Description

PROCESS FOR THE PREPARATION OF 3-HYDROXYMORPHINAN DERIVATIVES

FIELD OF THE INVENTION

[0001] The present invention generally relates to processes for the synthesis of intermediate or end product morphinans. More specifically, the invention is directed to improved processes for the synthesis of 3-hydroxymorphinan derivatives by O-demethylatioπ of 3-methoxymorphinan derivatives.

BACKGROUND OF THE INVENTION

[0002] Oxymorphone is usually made by O-demethylation of oxycodone with a variety of O- demethylation reagents such as BEta MeSOϊH/methionine and HBr. The yield for this O-demethylation reaction ranges from 30% to 80% depending on the particular process conditions used. A low yield may result as a consequence of the strong acids or Lewis acids reacting with the functional groups of, for example, oxycodone and the product oxymorphone. Thus, use of these reagents leads to unavoidable reductions in the yield of oxymorphone due to formation of side products.

SUMMARY OF THE INVENTION

[0003] Among the various aspects of the present invention is the provision of a process for the conversion of the side products from the O-demethylation of 3-methoxymorphinan derivatives to 3- hydroxymorphinan derivatives.

[0004] Another aspect is a process for the preparation of a morphtnan compound corresponding to the formula:

the process comprising hydroiyzing a compound corresponding to the formula (I):

in a protic solvent to form an intermediate compound [U) corresponding to the formula

and, heating a mixture comprising an aqueous solvent and the compound (II), in an aqueous solvent, at a pH of about

1 to about 6 to form compound (III), wherein:

R is selected from the group consisting of hydrogen, alkyl, aryl, acyl, -SR⁴, -OR⁴, and -NR⁴R⁵;

R¹ and R² are independently selected from the group consisting of hydrogen, alkyl, B(0H)2, and R¹ and R², along with the atoms to which they are attached, form a 5-membered ring having a fifth ring member B(OH); provided, however, that at least one of R¹ and R² is B(OH)₂ or that R¹ and R² form the 5-membered ring;

R³ is selected from the group consisting of hydrocarbyl, substituted hydrocarbyl, and a nitrogen protecting group;

R⁴ and R⁶ are independently selected from the group consisting of hydrogen, alkyl, aryl, and acyl;

R⁶ and R⁷ are independently selected from the group consisting of hydrogen, halogen, hydroxyl, NH₂, SH, hydrocarbyl, and substituted hydrocarbyl, wherein R⁶ and R⁷ may together form a group selected from the group consisting of =0 and =S;

R⁸ and R⁹ are independently selected from the group consisting of hydrogen, halogen, hydroxy!, NH₂, CN, hydrocarbyl, and substituted hydrocarbyl; and X is selected from the group consisting of chloro, bromo, and iodo.

[0005] Yet another aspect is a process for the preparation of a moφhinan compound (111) corresponding to the formula:

the process comprising heating a mixture comprising an aqueous solvent and a compound (II), corresponding to the formula:

in an aqueous solvent, at a pH of about 1 to about 6 to form compound (III) wherein R₁ R³, R⁴, R⁵, R⁶, R⁷, R⁸, R⁹, and X are as defined above.

[0006] A further aspect of the invention is a morphinan compound, or pharmaceutically acceptable salt thereof, the compound corresponding to the formula:

wherein R₁ R¹, R², R³, R\ R⁵, R⁶, R⁷, R⁸, R⁹, and X are as defined above.

[0007] Another aspect is a morphiπan compound, or a pharmaceutically acceptable salt thereof, the compound corresponding to the formula:

wherein R, R³, R⁴, R⁵ ₍ R⁶, R⁷, R⁸, R⁹, and X are as defined above.

[0008] Other objects and features will be in part apparent and in part pointed out hereinafter.

DETAILED DESCRIPTION

[0009] Generally, various aspects of the process described herein include the hydrolysis of a major side product in the preparation of 3-hydroxymorphinan derivatives (III) by O-demethylation of 3- methoxymorphinan derivatives. side products

Scheme A

[0010] As seen from Scheme A, a methyl group attached to the oxygen at the C3 position of a morphinan compound is removed to form an O-demethylated moφhinan compound. This demethylation reaction occurs under reaction conditions that produce various side products. When using boron-based Lewis acids, some of the side products of this demethylation reaction are compounds of formula I.

[0011] As depicted in Scheme 1 , these side products have been identified as various isomers of compound I that include boron complexes as described below. These compound I isomers are hydrolyzed in a protic solvent to form isomers of compound II. The hydrolysis reaction decreases the pH of the reaction mixture. The method comprises increasing the pH of the reaction mixture to about 1 to about 6 such that compound Il is hydrolyzed in the presence of heat to form compound III.

Scheme 1

The identity of R, R¹, R², R³, R⁴, R⁵, R⁶, R⁷, R⁸, R⁹, and X are identified above.

[0012] In some of the process embodiments, the reaction of a 3-methoxymorphinan compound with BBr3 forms boric derivatives that are hydrolyzed to a 3-hydroxymorphinan compound in an aqueous solution. Significant side products are boric derivatives of 5-bromo-3, 4-oxymorphinan isomers (e.g., compound IA); the percent yield of these side products is about 15% to 35%. The boric derivatives may be converted to 5-bromo-3, 4-dihydroxymorphinan isomers of compound HA by a hydrolysis reaction in a protic soivent as shown in Scheme 1A below. The reaction mixture comprising the isomers of compound HA becomes very acidic (pH less than O) after boric complexes of compound IA are hydrolyzed. Heating the reaction mixture resulted in the decomposition of the 3-hydroxymorphinan derivatives and isomers of compound IiA. Alternatively, if the pH of the reaction mixture was increased to a pH greater than 5, the 3-hydroxymorphinan did not decompose, but isomers of compound HA did begin to decompose. Greater than 50% of the amount of the side products (e.g., compound HA) decomposed when treated with a base at a pH of about 7 to 10. On treatment of compound HA with a strong base like 1 N NaOH, one isomer was partially converted to 3- hydroxymorphinan but the other isomer decomposed. Thus, control of the pH during the conversion of isomers of compound HA to compound III is important.

Scheme 1A [0013] The present invention further includes processes for conversion of isomers of compound Il into 3-hydroxymorphiπan derivatives (e.g., compound 111). These processes allow the transformation of isomers of compound Il to 3-hydroxymorphinan derivatives at a pH of about 1 to about 6 with a minimum amount of decomposition from reaction of an α-Br-ketone with water or hydroxide.

[0014] Solid 3-hydroxymorphinan compound is recovered in high yield afterthe processes of the invention are carried out and the pH is adjusted to greater than about 8. The addition of the processes described herein to various processes to prepare 3-hydroxymorphinan derivatives provides solvent savings and time savings in unit operations and overall processing as compared to conventional processes for preparing 3- hydroxymorphinan derivatives, such as oxymorphone.

[0015] 3-Methoxymorρhinan derivatives, such as oxycodone, used in the O-demethylation reaction can be prepared by various methods known in the art. For example, various methods for preparing oxycodone are described in U.S. Patent Nos. 7,153,966; 6,864,370; 6,469,170; 6,177,567; and 6,008,355; incorporated by reference herein in their entirety.

[0016] For purposes of discussion, the ring atoms of the morphinans of the present invention are numbered as follows.

[0017] Schemes 1 and 1 A above depict the chemical conversion of compound I to compound Il and further to the desired product compound III; oxymorphone is a compound of Formula 111. Each of these compounds is described in more detail below.

Compound III

[0018] The desired product is a compound having formula ill. These compounds can be prepared from the side products (e.g., compound I) by the processes described herein. Thus, the processes of the present invention are employed to prepare compounds having formula ill:

wherein R, R³, R⁴, R⁵, R⁶, R⁷, R⁸, and R⁹ are as defined above. In some embodiments, R³ is alkyi, allyl, aryl, or acyl. In various preferred embodiments, R³ is alky!. In some of these embodiments, R³ is methyl, cyclopropyl, isobutyl, or cyclobutyl; preferably, R³ is methyl. In certain embodiments, R is hydrogen or hydroxyl; preferably, R is hydroxyl. In some of these embodiments, R³ is methyl and R is hydrogen or hydroxyl; in preferred embodiments, R³ is methyl and R is hydroxyl.

[0019] The optical activity of compounds having formula III may be (-) or (+). Furthermore, the configuration of the chiral carbons, C5, C13, C14, and C9, respectively, may be RRRR₁ RRSR, RRRS, RRSS, RSRR, RSSR, RSRS, RSSS, SRRR, SRSR, SRRS, SRSS, SSRR, SSSR, SSRS₁ or SSSS.

Compound t

[0020] The side products from the O-demethylation of 3-methoxymorphinan derivatives has been identified as compounds having formula 1:

wherein R, R¹, R², R³, R⁴, R⁵, R⁶, R⁷, R^β, R⁹, and X are defined as above. Compounds of formula I may be converted to compounds of formula Il using the processes described herein.

Page 8 of 25 [0021] In some embodiments, R³ is alkyl, ally], aryl, or acyl. In various preferred embodiments, R³ is alkyl. In some of these embodiments, R³ is methyl, cyclopropyl, isobutyl, or cyclobutyl; preferably, R³ is methyl. In certain embodiments, R is hydrogen or hydroxyl; preferably, R is hydroxyl. Also, X may be bromo or chloro; preferably, X is bromo.

[0022] In various embodiments, at least one of R¹ or R² is B(OH)2 and the other of R¹ or R² is hydrogen; or R¹ and R² form a 5-membered ring having a fifth ring member B(OH). In some of these embodiments, R¹ or R² is B(OH)₂ and the other of R¹ or R² is hydrogen; preferably, R¹ is hydrogen and R² is B(OH)₂. !n other embodiments, R¹ and R² form a 5-membered ring having a fifth ring member B(OH) .

[0023] In various embodiments, R³ is methyl, cyclopropyl, isobutyl, or cyclobutyl, R is hydrogen or hydroxyl, X is bromo, and one of R¹ or R² is B(OH)₂ and the other of R¹ or R² is hydrogen; or R¹ and R² form a 5-membered ring having a fifth ring member B(OH); in preferred embodiments, R³ is methyl, R is hydroxyl, X is bromo, R¹ is hydrogen, and R² is B(OH)₂.

[0024] The optical activity of compounds having formula I may be (-) or (+). Furthermore, the configuration of thechira! carbons, C13, C14, and C9, respectively, maybe RRR, RRS, RSR, RSS, SRR₁ SRS, SSR, or SSS.

Compound Il

[0025] An intermediate in the process of the present invention is a compound having formula

wherein R, R³, R⁴, R⁵, R⁶, R⁷, R⁶, R⁹, and X are as defined above. This compound is prepared by hydrolyzing compounds of formula I in a pratic solvent.

[0026] In some embodiments, R³ is alkyl, ally!, aryl, or acyl. In various preferred embodiments, R³ is alkyl. In some of these embodiments, R³ is methyl, cyclopropyl, isobutyl, or cyclobutyl; preferably, R³ is methyl. In certain embodiments, R is hydrogen or hydroxyl; preferably, R is hydroxyl. In certain embodiments, X is bromo or chloro; preferably, X is bromo. In some of these embodiments, R³ is methyl, R is hydrogen or hydroxyl, and X is bromo; in preferred embodiments, R³ is methyl, R is hydroxyl, and X is bromo. [0027] The optical activity of compounds having formula 11 may be {-) or (+). Furthermore, the configuration of C13, C14, and C9, respectively, may be RRR, RRS, RSR, RSS, SRR, SRS, SSR₁ or SSS.

Process Conditions

Conversion of Compound I to Compound Il

[0028] Generally, the hydrolysis reaction converting compounds of formula I to compounds of formula Il takes place in a protic solvent. The protic solvent may be selected from the group consisting of water, methanol (MeOH), ethanol (EtOH), isopropyl alcohol (IPA)₁ and combinations thereof. Sn various preferred embodiments, the solvent is water.

Conversion of Compound H to Compound III

[0029] Typically, the hydrolysis reaction to convert compounds of formula Ii to compounds of formula III occurs at a pH of about 1 to a pH of about 6. In order for this reaction to occur at this pH, a base is added after compounds of formula I are converted to compounds of formula II. In various embodiments, the pH of this hydrolysis reaction is about 2 to about 4; preferably, about 3 to about 4.

[0030] Further, this hydrolysis reaction mixture is heated to a temperature of about 20⁰C to about 120⁰C during the process of conversion to compounds of formula III. In some embodiments, the reaction mixture is heated to a temperature of about 6O⁰C to about 90⁰C.

DEFINITIONS

[0031] The compounds described herein may have asymmetric centers. Compounds of the present invention containing an asymmetrically substituted atom may be isolated in optically active or racemic form. Cis and trans geometric isomers of the compounds of the present invention are described and may be isolated as a mixture of isomers or as separated isomeric forms. All chiral, diastereomeric, racemic forms and all geometric isomeric forms of a structure are intended, unless the specific stereochemistry or isomeric form is specifically indicated. All processes used to prepare compounds of the present invention and intermediates made therein are considered to be part of the present invention.

[0032] The term "acyl," as used herein alone or as part of another group, denotes the moiety formed by removal of the hydroxy group from the group COOH of an organic carboxylic acid, e.g., RC(O)-, wherein R is R¹, R¹O-, R¹RΪN-, or R¹S-, R¹ is hydrocarbyl, heterosubstituted hydrocarbyl, or heterocyclo, and R² is hydrogen, hydrocarbyl or substituted hydrocarbyl.

[0033] The term "acyloxy," as used herein alone or as part of another group, denotes an acyl group as described above bonded through an oxygen linkage (O), e.g., RC(O)O- wherein R is as defined in connection with the term "acyl."

[0034] The term "alkyl" as used herein describes groups which are preferably lower atkyl containing from one to eight carbon atoms in the principal chain and up to 20 carbon atoms. They may be

Page 10 of 25 straight or branched chain or cyclic and include methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, tert-butyl, pentyl, hexyl, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, and the like.

[0035] The term "alkenyl" as used herein describes groups which are preferably lower aikenyl containing from two to eight carbon atoms in the principal chain and up to 20 carbon atoms. They may be straight or branched chain or cyclic and include ethenyl, propenyl, isopropenyl, butenyl, isobutenyi, hexenyl, and the like.

[0036] The term "alkynyi" as used herein describes groups which are preferably lower alkynyl containing from two to eight carbon atoms in the principal chain and up to 20 carbon atoms. They may be straight or branched chain and include ethynyS, propynyl, butynyl, isobutynyl, hexynyl, and the like.

[0037] The term "allyl" refers to an aikene hydrocarbyl group comprising a vinyl group attached to a methylene group.

[0038] The term "aromatic" as used herein alone or as part of another group denotes optionally substituted homo- or heterocyclic aromatic groups. These aromatic groups are preferably monocyclic, bicyclic, or tricyclic groups containing from 6 to 14 atoms in the ring portion. The term "aromatic" encompasses the "aryl" and "heteroaryl" groups defined below.

[0039] The term "aryl" as used herein alone or as part of another group denote optionally substituted homocyclic aromatic groups, preferably monocyclic or bicyclic groups containing from 6 to 12 carbons in the ring portion, such as phenyl, biphenyl, naphthyl, substituted phenyl, substituted biphenyl or substituted naphthyl. Phenyl and substituted phenyl are the more preferred aryl.

[0040] The terms "halogen" or "halo" as used herein alone or as part of another group refer to chlorine, bromine, fluorine, and iodine,

[0041] The term "heteroatom" shall mean atoms other than carbon and hydrogen.

[0042] The terms "heterocyclo" or "heterocyclic" as used herein alone or as part of another group denote optionally substituted, fully saturated or unsaturated, monocyclic or bicyclic, aromatic or non- aromatic groups having at least one heteroatom in at least one ring, and preferably 5 or 6 atoms in each ring. The heterocyclo group preferably has 1 or 2 oxygen atoms and/or 1 to 4 nitrogen atoms in the ring, and is bonded to the remainder of the molecule through a carbon or heteroatom. Exemplary heterocyclo groups include heteroaromatics as described below. Exemplary substituents include one or more of the following groups: hydrocarbyl, substituted hydrocarbyl, hydroxy, protected hydroxy, acyl, acyloxy, alkoxy, alkenoxy, alkynoxy, aryloxy, halogen, amido, amino, cyano, ketals, acetals, esters and ethers.

[0043] The term "heteroaryl" as used herein alone or as part of another group denote optionally substituted aromatic groups having at least one heteroatom in at least one ring, and preferably 5 or 6 atoms in each ring. The heteroaryl group preferably has 1 or 2 oxygen atoms and/or 1 to 4 nitrogen atoms in the ring, and is bonded to the remainder of the molecule through a carbon. Exemplary heteroaryls include furyl, benzofuryl, oxazolyl, isoxazolyl, oxadiazolyl, benzoxazolyi, benzoxadiazolyl, pyrrolyl, pyrazolyl, imidazolyl, triazolyl, tetrazolyl, pyridyl, pyrimidyl, pyrazinyl, pyridazinyl, indolyl, isoindolyl, indolizinyl, benzimidazolyi,

Page 11 of 25 indazolyl, benzotriazolyl, tetrazolopyridazinyl, carbazoiyl, purinyl, quinolinyl, isoquinolinyl, imidazopyridyl and the like. Exemplary substituents include one or more of the following groups: hydrocaityl, substituted hydrocarbyl, hydroxy, protected hydroxy, acyl, acyloxy, alkoxy, alkenoxy, alkynoxy, aryloxy, halogen, amido, amino, cyano, ketals, acetals, esters and ethers.

[0044] The terms "hydrocarbon" and "hydrocarbyi" as used herein describe organic compounds or radicals consisting exclusively of the eiements carbon and hydrogen. These moieties include alkyl, alkenyl, alkynyl, and aryl moieties. These moieties also include alkyl, alkenyi, alkynyl, and ary! moieties substituted with other aliphatic or cyclic hydrocarbon groups, such as alkaryl, alkenaryl and alkynaryl. Unless otherwise indicated, these moieties preferably comprise 1 to 20 carbon atoms.

[0045] The "substituted hydrocarbyl" moieties described herein are hydrocarbyl moieties which are substituted with at least one atom other than carbon, including moieties in which a carbon chain atom is substituted with a hetero atom such as nitrogen, oxygen, silicon, phosphorous, boron, sulfur, or a halogen atom. These substituents include halogen, heterocyclo, alkoxy, alkenoxy, aryloxy, hydroxy, protected hydroxy, acyl, acyloxy, nitro, amino, amido, nitro, cyano, ketals, acetals, esters and ethers.

[0046] When introducing elements of the present invention or the preferred embodiments(s) thereof, the articles "a", "an", "the" and "said" are intended to mean that there are one or more of the elements. The terms "comprising", "including" and "having" are intended to be inclusive and mean that there may be additional elements other than the listed elements.

[0047] Having described the invention in detail, it will be apparent that modifications and variations are possible without departing from the scope of the invention defined in the appended claims.

EXAMPLES

[0048] The following non-limiting examples are provided to further illustrate the present invention.

Example 1: Reaction of oxycodone with BBr₃, followed by hydrolysis.

[0049] Oxycodone (20.0 g) was suspended in chlorobenzene {300 mL) in a reactor 1. Boron tri bromide (BBr3, 20.0 mL) was added slowly to form a suspension (an exothermic reaction was observed). The reaction temperature was maintained below 25⁰C during the addition. Stirring at 15 to 25°C was carried out for 14 hours. The solution was added to a reactor 2 that had been pre-filled with 170 mL of water. The temperature reached 50 to 55°C and was maintained at a temperature below 65°C during the addition. After the transfer, some solid residue still remained in reactor 1.

[0050] The mixture in reactor 2 was stirred at 60 to 65⁰C to dissolve the solids for about 10 minutes and then allowed to separate into two clear layers. The aqueous solution in reactor 2 was transferred back to reactor 1. After stirring at 60 to 65°C for 15 to 30 minutes, all the solids were in solution in reactor 1. The organic layer in reactor 2 was extracted with H3PO4/H2O solution (5% wt/wt, 20 mL) and the aqueous layer

Page 12 of 25 was transferred to reactor 1 The solution in reactor 1 was maintained at 60 to 65°C, extracted with chlorobenzene (40 mL), and then separated into two phases. The organic layer in reactor 1 was transferred to reactor 2 to give 350 mL of solution (combined organic layer) that was discarded. To the aqueous layer in reactor 1 at 60 to 65°C, 50% NaOH was added. The pH was adjusted with 50% NaOH (about 30 mL) to pH 2.5 to give a small amount of precipitate. The temperature was maintained below 80⁰C during the addition of NaOH. After heating at 80⁰C for 2.5 hours, a solution formed.

[0051] The hot solution in reactor 1 was cooled to room temperature. Concentrated ammonium hydroxide (about 40 mL) was added and the pH was adjusted to 9.5. Stirring was continued at room temperature for 10 minutes at pH 9.5. Pure oxymorphone (0.2 g) was added to act as a seed for crystallization. Stirring was continued at room temperature for 2 hours. The solid was separated by filtration and washed with water (2 X 50 mL). The wet solid was dried under vacuum (40 to 60 mmHg) at 75°C for 16 hours to give 17.57 g of solid oxymorphone. Yield: crude wt./wt.%, weight of crude product/weight of starting material was 88%; mol/mol%, oxymorphone in the product/oxycodone in the starting material was 77%.

Example 2: Conversion of by-products to oxymorphone under acidic conditions.

[0052] Oxycodone (10.0 g) was suspended in chloroform {CHCI3, 150 mL) in a reactor A.

Boron tribromide (BBr₃, 10.0 mL) was added slowly and an exotherm was observed. The reaction temperature was maintained below 25°C during the addition. Stirring of the mixture was continued at room temperature for

14 hours. The materia! was transferred to reactor B that was pre-filled with 85 mL of water. The temperature reached 50 to 55°C and was maintained below 55⁰C during the addition. After transfer of the mixture to reactor B₁ some solid residue still remained in reactor A. The mixture in reactor B was stirred at 50 to 55°C to dissolve the solid (about 15 minutes) and then when stirring was stopped, the mixture separated into two clear layers. The aqueous solution in reactor B was transferred back to reactor A. The mixture was stirred at 50 to 55° C for

15 to 30 minutes to dissolve all the solids. The organic layer in reactor B was extracted with H3PO4/H2O solution (2% wt/wt, 15 mL). The aqueous extraction was transferred to reactor A. The solution in reactor A was extracted with dichloroethane (30 mL) and then allowed to separate into two phases.

[0053] The aqueous layer was then separated into two portions, where 10 mL of the aqueous layer was added to flask A and another 10 mL of the aqueous layer was added to flask B. The solution in flask A was heated 8O⁰C for 2 hours and cooled to room temperature. The solution in flask A was then diluted to 100 mL with 1% acetic acid in water for HPLC analysis (sample 2-A). The solution in flask B was treated with 50% NaOH to pH 2.6 and was then heated 8O⁰C for 2 hours and cooled to room temperature. The solution in flask B was then diluted to 100 mL with 1% acetic acid in water for HPLC analysis (sample 2-B). The data in Table 1 are the area of oxymorphone, area/area% of oxymorphone, and area/area% of 5-Bromo-14- hydroxymorphinane isomers (IiB), as analyzed by HPLC.

Table 1. Yield of Compounds

Page 13 of 25

[0054] The isomers HA on sample 2-B were almost completely hydrolyzed to oxymorphone at pH 2.6 at 8O⁰C for 2 hours.

(HB)

Example 3: pH study for conversion to oxymorphone.

[0055] The process of Example 2 through the extraction with dichloroethane was used to produce a mixture containing oxymorphone and isomers of compound HB. This mixture was added to five vials (3.0 ml for each vial). Sample 3.1 was set aside at room temperature for 2 hours and diluted to 10.0 mL for HPLC analysis. Samples 3.2 to 3.6 were diluted to 6.0 mL with the reagents as shown in Table 2 to a predetermined pH value. Samples 3.1 to 3.6 were heated at 95⁰C for 2 hours. The solution in each vial was then diluted to 10.0 mL for HPLC analysis. Table 3 shows the results of the HPLC analysis.

Table 2. Yield of Qx mor hone

Table 3. HPLC Anal sis

Page 14 of 25

[0056] Entries 3.2 to 3.6 in Table 3 showed that the 5-bromo-14-hydroxymoφhinane isomers of compound HB were converted to oxymorphone in a pH range from about 0.7 to about 9.0. At a pH of about 9, a significant portion of the HB isomers decomposed. Further, the maximum yield of oxymorphone was obtained at a pH of about 2.6.

Page 15 of 25

Claims

CLAIMSWhat is Claimed is:

1. A process for the preparation of a morphinan compound (III) corresponding to the formula:

the process comprising hydroiyzing a compound (I) corresponding to the formula:

in a protic solvent to form an intermediate compound (Ii) corresponding to the formula:

and heating a mixture comprising an aqueous solvent and the compound (!I), at a pH of about 1 to about 6, to form compound (III), wherein

Page 16 of 25 R is selected from the group consisting of hydrogen, alkyl, aryl, acyl, -SR⁴, -OR⁴, and - NR⁴R⁵;

R¹ and R² are independently selected from the group consisting of hydrogen, alkyl, B(0H)2, and R¹ and R², along with the atoms to which they are attached, form a 5-membered ring having a fifth ring member B(OH); provided, however, that at least one of R¹ and R² is B(0H)2 or that R¹ and R² form the 5-membered ring;

R⁴ and R⁵ are independently selected from the group consisting of hydrogen, alkyl, aryl, and acyl;

R⁶ and R⁷ are independently selected from the group consisting of hydrogen, halogen, hydroxy!, NH₂, SH, hydrocarbyl, and substituted hydrocarbyl, wherein R⁶ and R⁷ may together form a group selected from the group consisting of =0 and =S;

R⁸ and R⁹ are independently selected from the group consisting of hydrogen, halogen, hydroxyl, NH₂, CN, hydrocarbyl, and substituted hydrocarbyl; and

X is selected from the group consisting of chloro, bromo, and iodo.

2. A process for the preparation of a morphinan compound (III) corresponding to the formula:

the process comprising heating a mixture comprising an aqueous solvent and a compound (II) corresponding to the formula:

Page 17 of 25

at a pH of about 1 to about 6 to form compound (III), wherein:

R is selected from the group consisting of hydrogen, alkyl, aryl, acy!, -SR⁴, -OR⁴, and -

R⁶ and R⁷ are independently selected from the group consisting of hydrogen, halogen, hydroxy!, NH2, SH, hydrocarbyl, and substituted hydrocarbyl, wherein R⁶ and R⁷ may together form a group selected from the group consisting of =0 and =S;

X is selected from the group consisting of chloro, bromo, and iodo.

3. The process of claim 1 , wherein one of R¹ and R² is hydrogen and the other of R¹ and R² is B(0H)2 or R¹ and R², together with the atoms to which they are attached, form the 5-membered ring; and the protic solvent is selected from the group consisting of water, methanol, ethanol, isopropyl alcohol, and combinations thereof.

4. The process of any one of claims 1 to 3, wherein R³ is selected from the group consisting of alkyl, allyl, aryl, and acyl.

5. The process of any one of claims 1 to 4, wherein the mixture is heated to a temperature of about 60^DC to about 90⁰C during the process of conversion to compound (III); and the mixture is adjusted to a pH of about 2 to about 3.

Page 18 of 25

6. The process of any one of claims 1 to 5, wherein X is bromo; R³ is alkyl; and R is selected from the group consisting of hydrogen and hydroxyl.

7. The process of any one of claims 1 to 6, wherein the optical activity of compounds (I)₁ (II), and (ill) is (-) or(+), and the configuration of C13, C14, and C9, respectively, of compounds (I) and (II) is selected from the group consisting of RRR, RRS, RSR₁ RSS, SRR, SRS, SSR, and SSS, and the configuration of C5, C13, C14, and C9, respectively, of compound (111) is selected from the group consisting of RRRR₁ RRSR, RRRS, RRSS, RSRR, RSSR₁ RSRS, RSSS, SRRR, SRSR, SRRS₁ SRSS, SSRR, SSSR, SSRS, and SSSS.

Page 19 of 25

8. A morphiπan compound, or pharmaceutically acceptable salt thereof, the compound corresponding to the formula:

wherein:

R is selected from the group consisting of hydrogen, alky], aryl, acyl, -SR⁴, -OR⁴, and -

NR⁴R⁵;

R³ is selected from the group consisting of alkyl, aryl, acy!, and a nitrogen protecting group;

R⁶ and R⁷ are independently selected from the group consisting of hydrogen, halogen, hydroxyl, NH2, SH, hydrocarbyl, and substituted hydrocarbyl, wherein R⁶ and R⁷ may together form a group selected from the group consisting of =0 and =S;

R⁸ and R⁹ are independently selected from the group consisting of hydrogen, halogen, hydroxyl, NH2, CN, hydrocarbyl, and substituted hydrocarbyl; and

X is selected from the group consisting of chloro, bromo, and iodo.

9. The compound of claim 8 having the structure:

wherein:

Page 20 of 25 R⁶ and R⁷ are independently selected from the group consisting of hydrogen, halogen, hydroxyl, NH₂, SH, hydrocarbyl, and substituted hydrocarbyl, wherein R⁶ and R⁷ may together form a group selected from the group consisting of =0 and =S; and

R⁸ and R⁹ are independently selected from the group consisting of hydrogen, halogen, hydroxy!, NH₂, CN₁ hydrocarbyl, and substituted hydrocarbyi.

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10. A morphinan compound, or pharmaceutically acceptable salt thereof, the compound corresponding to the formula:

wherein:

R is selected from the group consisting of hydrogen, alkyl, aryl, acyl, -SR⁴, -OR⁴, and -

NR⁴R⁵;

R³ is selected from the group consisting of alkyl, aryl, acyl, and a nitrogen protecting group;

R⁴ and R⁵ are independently selected from the group consisting of hydrogen, alky!, aryl, and acyl;

X is selected from the group consisting of chloro, bromo, and iodo.

11. The compound of any of claims 8 or 10, wherein X is bromo; R³ is alkyl; and R is selected from the group consisting of hydrogen and hydroxyl.

12. The compound of claim 11 , wherein R³ is selected from the group consisting of methyl, cyclopropyl, isobutyl, and cyclobutyl.

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13. The compound of claim 10 having the structure:

wherein:

R⁶ and R⁷ are independently selected from the group consisting of hydrogen, halogen, hydroxyl, NH2, SH, hydrocarbyl, and substituted hydracarbyl, wherein R⁶ and R⁷ may together form a group selected from the group consisting of =0 and =S; and

R⁸ and R⁹ are independently selected from the group consisting of hydrogen, halogen, hydroxyl, NHz, CN, hydracarbyl, and substituted hydracarbyl.

14. The compound of claim 10 having the structure:

wherein:

R⁶ and R⁷ are independently selected from the group consisting of hydrogen, halogen, hydroxyl, Ntø, SH, hydracarbyl, and substituted hydrocarby!, wherein R⁶ and R⁷ may together form a group selected from the group consisting of =0 and =S; and

R⁶ and R⁹ are independently selected from the group consisting of hydrogen, halogen, hydroxyl, NH2, CN, hydrocarbyl, and substituted hydracarbyl.

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5. The compound of any one of claims 8 to 14, wherein the optical activity of the compound is (-) or (+), and the configuration of C13, C14, and C9, respectively, is selected from the group consisting of RRR, RRS, RSR₁ RSS, SRR, SRS, SSR, and SSS.

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