Patent Application
20100036135
This application is directed to a process of making certain hydroisoindoline tachykinin receptor antagonists.
Substance P is a naturally occurring undecapeptide belonging to the tachykinin family of peptides, the latter being so-named because of their prompt contractile action on extravascular smooth muscle tissue. The tachykinins are distinguished by a conserved carboxyl-terminal sequence. In addition to substance P, the known mammalian tachykinins include neurokinin A and neurokinin B. The current nomenclature designates the receptors for substance P, neurokinin A, and neurokinin B as neurokinin-1 (NK-1), neurokinin-2 (NK-2), and neurokinin-3 (NK-3), respectively.
Tachykinin, and in particular substance P, antagonists are useful in the treatment of clinical conditions which are characterized by the presence of an excess of tachykinin, in particular substance P, activity, including disorders of the central nervous system, nociception and pain, gastrointestinal disorders, disorders of bladder function and respiratory diseases.
An alternative process for making compounds of the same structural class is disclosed in PCT/US05/02149, filed Jan. 26, 2005. The process is discussed further hereinunder.
The present invention is directed to a process for preparing certain hydroisoindoline compounds which are useful as neurokinin-1 (NK-1) receptor antagonists, and inhibitors of tachykinin and in particular substance P. The compounds are useful in the treatment of certain disorders, including emesis, urinary incontinence, depression, and anxiety.
In one aspect the invention encompasses a process of making hydroisoindoline tachykinin receptor antagonists of Formula (I)
and pharmaceutically acceptable salts thereof, wherein
R1 is selected from the group consisting of
(1) hydrogen
(2) C1-6alkyl, which is unsubstituted or substituted with halogen, hydroxyl or phenyl,
(3) cyclopentenone, which is unsubstituted or substituted with halogen, hydroxyl or methyl,
(4) —(CO)—C1-6 alkyl,
(5) —(CO)—NH2,
(6) —(CO)—NHC1-6alkyl, and
(7) —(CO)—N(C1-6alkyl)(C1-6alkyl);
X is independently selected from the group consisting of:
(1) hydrogen,
(2) fluorine, and
(3) methyl;
comprising:
Step (a) reacting a phenyl acetic acid of Formula (2)
with SOCl2 in an aprotic solvent optionally in the presence of a first catalyst to provide a compound of Formula (3)
Step (b) reacting the compound of Formula (3) with NHMeOMe in the presence of an aqueous inorganic base to provide a Weinreb amide of Formula (4)
Step (c) reacting the Weinreb amid of Formula 4 with a suitable Grignard reagent in an second aprotic solvent followed by a first quenching with Ac2O and a second quenching with an aqueous inorganic acid to provide an enone of Formula (5)
Step (d) reacting the enone of Formula (5) with a silane reagent in a third aprotic solvent and an organic base to provide a diene of Formula (6)
Step (e) reacting a diene of Formula (6) with a fumarate of Formula (7)
wherein R is (−)-menthyl
and a Lewis acid in a non-polar solvent to provide a compound of Formula (8)
Step (f) hydrolyzing a compound of Formula (8) with suitable hydrolysis reagents in an organic polar solvent to provide a compound of Formula (9)
Step (g) reducing the ketone functionality of the compound of Formula (9) with a first reducing agent, followed by reduction of CO2R with a second reducing agent in an aprotic solvent to provide a triol of Formula (10)
Step (h) reacting the triol of Formula (10) with an alkylsulfonyl chloride in the presence of an organic base to provide a compound of Formula (11)
wherein R2 is methyl, ethyl or propyl,
Step (i) reacting the compound of Formula (11) with compound of Formula (12)
in the presence of an acid catalyst in an aprotic solvent to produce a compound of Formula (13)
Step (j) cyclizing the compound of Formula (13) with allylamine in a polar solvent to provide a compound of Formula (14)
Step (k) reacting the compound of Formula (14) with third catalyst followed by addition of acid to provide a compound of Formula (15)
as an acid salt;
Step (l) reacting the acid salt of the compound of Formula (15) with a functionalizing reagent in a polar solvent to provide the compound of Formula (I)
Regarding Step (a), the ratio of equivalents of (2) to SOCl2 is typically 0.9:1 to 1:1.4. The preferred ratio is 1:1.2. For purposes of this application, the aprotic solvent includes toluene and benzene. Toluene is preferred. For purposes of this specification the first catalyst is defined to include Di-methylformamide. The ratio of molar equivalents of (2) to the first catalyst is 0.02. The reaction is typically carried out at a temperature range of 20 to 100° C. The preferred range is 60 to 80° C. The reaction is allowed to proceed until substantially complete, typically in 0.5 hours to 3 hours.
Regarding Step (b), the ratio of molar equivalents of (3) to NHMeOMe (as the HCl salt) is typically 1:1.2 to 1:2.0. The preferred ratio is 1:1.5. The reaction is typically carried out at a temperature range of −20 to 40° C. The preferred range is 0 to 20° C. The reaction is allowed to proceed until substantially complete, typically in 1 to 4 hours. In a preferred aspect Steps (a) and Step (b) is carried out in a single pot without intermediate isolation.
Regarding Step (c), the ratio of molar equivalents of (4) to Grignard reagent is typically 0.9:1.1 to 1.0:1.6. Preferably there is an excess of Grignard reagent, such as 20% to 40% excess. The Grignard reagents include vinyl magnesium or vinyl magnesium bromide. For purposes of this specification, the second aprotic solvent includes toluene, THF, Methyl-t-butyl ether (MTBE). The preferred solvent is a mixture of toluene and THF. The reaction is typically carried out at a temperature range of −78 to 0° C. The preferred range is −40 to −20° C. The reaction is quenched with 1.5 to 2 eq of acetic anhydride and then with an aqueous acidic buffer such as NH4Cl typically 0.5 to 2 hours after the reaction is begun.
Regarding Step (d), the molar ratio of (5) to silane reagent is typically 0.9:1 to 1:2.0. The preferred ratio is 1:1.6. Suitable silane reagents include chlorotriethylsilane, chlorotrimethylsilane, and t-butyldimethylchlorosilane. The preferred silane reagent is chlorotriethylsilane or chlorotrimethylsilane. The molar ratio of (5) to the organic base is typically 0.9:1 to 1:2.0. The preferred ratio is 1:1.6. Suitable organic base include triethylamine, ethyldiisopropylamine, and DBU. The preferred base is ethyldiisopropylamine. Suitable solvents include THF, MeCN, toluene, benzene, and ether. The preferred solvent is a mixture of MeCN, THF and toluene. The reaction is typically carried out at a temperature range of 0 to 30° C. The preferred range is 15-25° C. The reaction is allowed to proceed until substantially complete, typically in 16 to 30 hours.
Regarding Step (e), the molar ratio of (6) to (7) is typically 0.9:1 to 1:1.6. The preferred ratio is 1:1.2. The molar ratio of (6) to the Lewis acid catalyst is typically 1:1.2 to 1:3.0. The preferred ratio is 1:1.7. Suitable Lewis acid catalysts include Et2AlCl, iBu2AlCl, and EtAlCl2. The preferred Lewis acid catalyst is Et2AlCl. Suitable solvents include toluene, methylene chloride, 1,2-dichloroethane, and benzene. The preferred solvent is toluene. The reaction is typically carried out at a temperature range of −40 to 30° C. The preferred range is 0 to 20° C. The reaction is allowed to proceed until substantially complete, typically in 24 to 48 hours.
Regarding Step (f), the molar ratio of (8) to hydrolysis agent is typically 0.9:1 to 1:2.0. The preferred ratio is 1:1.2. Suitable hydrolysis agents include aqueous HCl, HBr, HF, and HI. The preferred hydrolysis agent is aqueous HCl. Suitable solvents include MeCN and THF. The preferred solvent is MeCN. The reaction is typically carried out at a temperature range of 0 to 40° C. The preferred range is 15 to 25° C. The reaction is allowed to proceed until substantially complete, typically in 1 to 4 hours.
Regarding Step (g), the molar ratio of (9) to the first reducing agent is typically 0.9:1 to 1:1.8. The preferred ratio is 1:1.5. Suitable first reducing agents include LiAl(OtBu)3H and NaBH4. The preferred first reducing agent is LiAl(OtBu)3H. The molar ratio of (9) to the second reducing agent is typically 1:1.2 to 1:2.5. The preferred ratio is 1:1.3. Suitable second reducing agents include LiAlH4 and LiBH4. The preferred second reducing agent is LiAlH4. Suitable solvents include THF and diglyme. The preferred solvent is THF. The reaction is typically carried out at a temperature range of −70 to 20° C. for the first reduction and −20 to 60 C for the second reduction. The preferred range is −40 to −25° C. for the first reduction and 20 to 40° C. for the second reduction. The reaction is allowed to proceed until substantially complete, typically in 1 to 5 hours for the first reduction and 2 to 18 hours for the second reduction.
Regarding Step (h), the molar ratio of (10) to the alkanesulfonyl chloride is typically 1:2 to 1:3. The preferred ratio is 1:2.3 to 1:2.4. Suitable alkanesulfony chlorides include n-propanesulfonyl chloride, ethanesulfonyl chloride, and methanesulfonyl chloride. The preferred alkanesulfonyl chloride is n-propanesulfonyl chloride. The molar ratio of (10) to the organic base is typically 1:2 to 1:3. The preferred ratio is 1:2.3 to 1:2.4. Suitable organic bases include 2,4,6-collidine, ethyldiisopropylamine, tetramethylpiperidine, pentamethylpiperidine, 2,6-lutidine, and triethylamine. The preferred organic base is 2,4,6-collidine. Suitable solvents include MeCN, THF, methylene chloride, EtOAc, iPrOAc, 1,2-dichloroethane. The preferred solvent is a mixture of MeCN and EtOAc. The reaction is typically carried out at a temperature range of −20 to 40° C. The preferred range is 15 to 25° C. The reaction is allowed to proceed until substantially complete, typically in 3 to 20 hours.
Regarding Step (i), the molar ratio of (11) to (12) is typically 1.2:1 to 2.5:1. The preferred ratio is 1.4:1 to 1.6:1. The molar ratio of (11) to the acid catalyst is typically 1:0.05 to 1:0.40. The preferred ratio is 1:0.15 to 1:0.25. Suitable acid catalysts include HBF4, BF3, and CF3SO3H. The preferred acid catalyst is HBF4. Suitable solvents include methylene chloride, 1,2-dichloroethane, toluene, trifluorotoluene, cyclohexane. The preferred solvent is a mixture of methylene chloride, cyclohexane and trifluorotoluene. The reaction is typically carried out at a temperature range of −20 to 20° C. The preferred range is −15 to −10° C. The reaction is allowed to proceed until substantially complete, typically in 15 to 24 hours.
Regarding Step (j), the molar ratio of (13) to allylamine is typically 1:5 to 1:10. The preferred ratio is 1:5. Suitable solvents include 2-propanol, MeOH, EtOH, i-PrOAc. The preferred solvent is 2-propanol. The reaction is typically carried out at a temperature range of 55-80° C. The preferred range is 55-60° C. The reaction is allowed to proceed until substantially complete, typically in 3 to 6 hours.
Regarding Step (k), the molar ratio of (14) to catalyst is typically 1:0.01 (1 mole %) to 1:0.05 (5 mole %). The preferred ratio is 1:0.01. The molar ratio of (14) to water is typically 1:4.5. The preferred ratio is 1:4.5. Suitable solvents include THF, MTBE. The preferred solvent is THF. The reaction is typically carried out at a temperature range of room temperature to 50° C. The preferred range is 40-45° C. The reaction is allowed to proceed until substantially complete, typically in 2 to 12 hours.
Regarding Step (l), the molar ratio of (15) to X′ is typically 1:1.1 to 1:1.5. The preferred ratio is 1:1.1. Suitable solvents include 2-propanol, toluene. The preferred solvent is 2-propanol. The functionalizing agent includes, but is not limited to, an alkyl(aryl)halide, an alkyl(aryl)triflate, a dialkyl(aryl)carbonic anhydride, an acyl halide, an alkyl(aryl)chloroformate, alkyl(aryl)sulfonylhalide, a haloaklyl(aryl)sulfonylhalide, an alkanoyl halide, a benzylic halide, a halo-CON(alkyl or aryl)2, an alkyl(aryl) aldehyde or ketone in the presence of a reducing agent, a sulfonylate, for example a mesylate or tosylate. The reaction is typically carried out at a temperature range of room temperature to 110° C. The preferred range is 60 to 75° C. The reaction is allowed to proceed until substantially complete, typically in 1 to 3 hours.
Within this embodiment the process of the present invention includes compounds wherein R1 is selected from the group consisting of:
(1) hydrogen,
(2) methyl,
(3) 2-phenylethyl,
(4) 2-hydroxyethyl,
(5) cyclopent-2-en-1-one,
(6) 5-hydroxycyclopent-2-en-1-one,
(7) 4-hydroxycyclopent-2-en-1-one,
(8) 2-methylcyclopent-2-en-1-one,
(9) acetyl,
(10) acetamido,
(11) methyl-acetamido, and
(12) dimethyl-acetamido.
Further within this embodiment, the present invention is directed to preparing compounds wherein R1 is hydrogen.
Also further within this embodiment, the present invention is directed to preparing compounds wherein R1 is methyl, 2-phenylethyl or 2-hydroxyethyl.
Also further within this embodiment, the present invention is directed to preparing compounds wherein R1 is:
which is unsubstituted or substituted with hydroxyl or methyl.
Also further within this embodiment, the present invention is directed to preparing compounds wherein R1 is acetyl, acetamido, methyl-acetamido or dimethyl-acetamido.
An embodiment of the present invention includes the preparation of compounds wherein X is hydrogen. An embodiment of the present invention includes compounds wherein X is fluorine. An embodiment of the present invention includes compounds wherein X is methyl.
Specific embodiments of the present invention includes the preparation of the compounds of the Examples herein and pharmaceutically acceptable salts thereof and individual enantiomers and diastereomers thereof.
The compounds of the present invention are useful in the prevention and treatment of a wide variety of clinical conditions which are characterized by the presence of an excess of tachykinin, in particular substance P, activity. Thus, for example, an excess of tachykinin, and in particular substance P, activity is implicated in a variety of disorders of the central nervous system. Such disorders include mood disorders, such as depression or more particularly depressive disorders, for example, single episodic or recurrent major depressive disorders and dysthymic disorders, or bipolar disorders, for example, bipolar I disorder, bipolar II disorder and cyclothymic disorder; anxiety disorders, such as panic disorder with or without agoraphobia, agoraphobia without history of panic disorder, specific phobias, for example, specific animal phobias, social phobias, obsessive-compulsive disorder, stress disorders including post-traumatic stress disorder and acute stress disorder, and generalised anxiety disorders; schizophrenia and other psychotic disorders, for example, schizophreniform disorders, schizoaffective disorders, delusional disorders, brief psychotic disorders, shared psychotic disorders and psychotic disorders with delusions or hallucinations; delirium, dementia, and amnestic and other cognitive or neurodegenerative disorders, such as Alzheimer's disease, senile dementia, dementia of the Alzheimer's type, vascular dementia, and other dementias, for example, due to HIV disease, head trauma, Parkinson's disease, Huntington's disease, Pick's disease, Creutzfeldt-Jakob disease, or due to multiple aetiologies; Parkinson's disease and other extra-pyramidal movement disorders such as medication-induced movement disorders, for example, neuroleptic-induced parkinsonism, neuroleptic malignant syndrome, neuroleptic-induced acute dystonia, neuroleptic-induced acute akathisia, neuroleptic-induced tardive dyskinesia and medication-induced postural tremour; substance-related disorders arising from the use of alcohol, amphetamines (or amphetamine-like substances) caffeine, cannabis, cocaine, hallucinogens, inhalants and aerosol propellants, nicotine, opioids, phenylglycidine derivatives, sedatives, hypnotics, and anxiolytics, which substance-related disorders include dependence and abuse, intoxication, withdrawal, intoxication delirium, withdrawal delirium, persisting dementia, psychotic disorders, mood disorders, anxiety disorders, sexual dysfunction and sleep disorders; epilepsy; Down's syndrome; demyelinating diseases such as MS and ALS and other neuropathological disorders such as peripheral neuropathy, for example diabetic and chemotherapy-induced neuropathy, and postherpetic neuralgia, trigeminal neuralgia, segmental or intercostal neuralgia and other neuralgias; and cerebral vascular disorders due to acute or chronic cerebrovascular damage such as cerebral infarction, subarachnoid haemorrhage or cerebral oedema.
Tachykinin, and in particular substance P, activity is also involved in nociception and pain. The compounds of the present invention will therefore be of use in the prevention or treatment of diseases and conditions in which pain predominates, including soft tissue and peripheral damage, such as acute trauma, osteoarthritis, rheumatoid arthritis, musculo-skeletal pain, particularly after trauma, spinal pain, myofascial pain syndromes, headache, episiotomy pain, and burns; deep and visceral pain, such as heart pain, muscle pain, eye pain, orofacial pain, for example, odontalgia, abdominal pain, gynaecological pain, for example, dysmenorrhoea, and labour pain; pain associated with nerve and root damage, such as pain associated with peripheral nerve disorders, for example, nerve entrapment and brachial plexus avulsions, amputation, peripheral neuropathies, tic douloureux, atypical facial pain, nerve root damage, and arachnoiditis; pain associated with carcinoma, often referred to as cancer pain; central nervous system pain, such as pain due to spinal cord or brain stem damage; low back pain; sciatica; ankylosing spondylitis, gout; and scar pain.
Tachykinin, and in particular substance P, antagonists may also be of use in the treatment of respiratory diseases, particularly those associated with excess mucus secretion, such as chronic obstructive airways disease, bronchopneumonia, chronic bronchitis, cystic fibrosis and asthma, adult respiratory distress syndrome, and bronchospasm; inflammatory diseases such as inflammatory bowel disease, psoriasis, fibrositis, osteoarthritis, rheumatoid arthritis, pruritis and sunburn; allergies such as eczema and rhinitis; hypersensitivity disorders such as poison ivy; ophthalmic diseases such as conjunctivitis, vernal conjunctivitis, and the like; ophthalmic conditions associated with cell proliferation such as proliferative vitreoretinopathy; cutaneous diseases such as contact dermatitis, atopic dermatitis, urticaria, and other eczematoid dermatitis. Tachykinin, and in particular substance P, antagonists may also be of use in the treatment of neoplasms, including breast tumours, neuroganglioblastomas and small cell carcinomas such as small cell lung cancer.
Tachykinin, and in particular substance P, antagonists may also be of use in the treatment of gastrointestinal (GI) disorders, including inflammatory disorders and diseases of the GI tract such as gastritis, gastroduodenal ulcers, gastric carcinomas, gastric lymphomas, disorders associated with the neuronal control of viscera, ulcerative colitis, Crohn's disease, irritable bowel syndrome and emesis, including acute, delayed or anticipatory emesis such as emesis induced by chemotherapy, radiation, toxins, viral or bacterial infections, pregnancy, vestibular disorders, for example, motion sickness, vertigo, dizziness and Meniere's disease, surgery, migraine, variations in intercranial pressure, gastro-oesophageal reflux disease, acid indigestion, over indulgence in food or drink, acid stomach, waterbrash or regurgitation, heartburn, for example, episodic, nocturnal or meal-induced heartburn, and dyspepsia.
Tachykinin, and in particular substance P, antagonists may also be of use in the treatment of a variety of other conditions including stress related somatic disorders; reflex sympathetic dystrophy such as shoulder/hand syndrome; adverse immunological reactions such as rejection of transplanted tissues and disorders related to immune enhancement or suppression such as systemic lupus erythematosus; plasma extravasation resulting from cytokine chemotherapy, disorders of bladder function such as cystitis, bladder detrusor hyper-reflexia, frequent urination and urinary incontinence, including the prevention or treatment of overactive bladder with symptoms of urge urinary incontinence, urgency, and frequency; fibrosing and collagen diseases such as scleroderma and eosinophilic fascioliasis; disorders of blood flow caused by vasodilation and vasospastic diseases such as angina, vascular headache, migraine and Reynaud's disease; and pain or nociception attributable to or associated with any of the foregoing conditions, especially the transmission of pain in migraine. The compounds of the present invention are also of value in the treatment of a combination of the above conditions, in particular in the treatment of combined post-operative pain and post-operative nausea and vomiting.
The compounds of the present invention are particularly useful in the prevention or treatment of emesis, including acute, delayed or anticipatory emesis, such as emesis induced by chemotherapy, radiation, toxins, pregnancy, vestibular disorders, motion, surgery, migraine, and variations in intercranial pressure. For example, the compounds of the present invention are of use optionally in combination with other antiemetic agents for the prevention of acute and delayed nausea and vomiting associated with initial and repeat courses of moderate or highly emetogenic cancer chemotherapy, including high-dose cisplatin. Most especially, the compounds of the present invention are of use in the treatment of emesis induced by antineoplastic (cytotoxic) agents, including those routinely used in cancer chemotherapy, and emesis induced by other pharmacological agents, for example, rolipram. Examples of such chemotherapeutic agents include alkylating agents, for example, ethyleneimine compounds, alkyl sulphonates and other compounds with an alkylating action such as nitrosoureas, cisplatin and dacarbazine; antimetabolites, for example, folic acid, purine or pyrimidine antagonists; mitotic inhibitors, for example, vinca alkaloids and derivatives of podophyllotoxin; and cytotoxic antibiotics. Particular examples of chemotherapeutic agents are described, for instance, by D. J. Stewart in Nausea and Vomiting: Recent Research and Clinical Advances, Eds. J. Kucharczyk et al, CRC Press Inc., Boca Raton, Fla., USA (1991) pages 177-203, especially page 188. Commonly used chemotherapeutic agents include cisplatin, dacarbazine (DTIC), dactinomycin, mechlorethamine, streptozocin, cyclophosphamide, carmustine (BCNU), lomustine (CCNU), doxorubicin (adriamycin), daunorubicin, procarbazine, mitomycin, cytarabine, etoposide, methotrexate, 5-fluorouracil, vinblastine, vincristine, bleomycin and chlorambucil [R. J. Gralla et al in Cancer Treatment Reports (1984) 68(1), 163-172]. A further aspect of the present invention comprises the use of a compound of the present invention for achieving a chronobiologic (circadian rhythm phase-shifting) effect and alleviating circadian rhythm disorders in a mammal. The present invention is further directed to the use of a compound of the present invention for blocking the phase-shifting effects of light in a mammal.
An alternative process for making compounds of the same class is disclosed in PCT/US05/02149, filed Jan. 26, 2005. Referring specifically to Example 7, the process can be summarized as shown in the scheme immediately below. Significant disadvantages are that the route is racemic and requires the chromatographic separation of both enantiomers and diastereomers after the reduction of racemic ketone IV. In addition, the synthesis requires 5 steps to bismesylate VIII from ketone IV (reduction, separation, etherification, reduction, mesylation). This route utilized a benzyl-protecting group of the octahydroisoindole. Removal of this group by palladium-catalized hydrogenation was followed by reaction with 1,3-cyclopentanedione to give the product of Example 7.
This reaction gives consistently high yield and high purity of material. No major side products have been identified. The final product is an oil (typically clear or slightly yellow) and is isolated with the above purity profile from the crude work up.
A 100 L extractor equipped with a reflux condenser, and a base scrubber was charged with toluene (49.2 L, KF≦100 ppm) and 4-fluorophenylacetic acid (1) was added (5.0 kg). This solution was heated to 70° C. Once 70° C. was reached the DMF (48 mL, KF≦150 ppm) was added and thionyl chloride (2.8 L) was slowly added over 3 hours.
This reaction is very sensitive to the quality of the Grignard reagent and the quench method. Major side products have been identified (A, B, C), and are shown above. The product is unstable when concentrated to an oil, and has moderate stability in solution. The final toluene solution should be kept cold and used in the next step without delay.
A 3 L round bottom flask equipped with an addition funnel was charged with the Weinreb amide 2 as a 61% wt solution in toluene (262 g tot mass; 157.2 g 2, 105 g toluene). This solution was diluted to a 0.5 M solution of amide 2 in toluene by addition of 1.32 L of toluene (KF of solution <150 ppm). This solution was cooled to −30° C., and vinyl magnesium chloride was slowly added.
To 90.8 g of the 7.29 wt % enone 3 solution in THF/MeCN/toluene obtained from step 2 at rt was added more dry MeCN (18 mL) and iPr2NEt. TESCl was then added slowly while maintaining rt. The solution was stirred at rt until LC revealed complete conversion (˜16 h).
The reaction was quenched with 2 wt % aq NH4Cl (70 mL). The organic layer was separated and washed with water (70 mL). It was then concentrated and flushed with toluene to ˜37 wt % with a KF of ˜200 ppm. Assay yield: 8.64 g, 77%. NMR shows <5% of the E-isomer.
To a 3-neck flask was charged toluene (500 mL) and (−)-menthol (157.8 g). The solution was cooled to −20° C. and fumaryl chloride (80.5 g of 95%) was charged with 80 mL toluene flush (no exotherm was observed). i-Pr2NEt (191 mL) was added over 30 min (fuming) with 20 mL toluene flush at −20° C. DMAP was added immediately afterwards. The dark slurry was then allowed to warm to 21° C. over ˜60 min to give a dark solution, which showed complete conversion by HPLC.
The toluene solutions of diene 4 (23.4 g, 37 wt %) and dimenthylfumarate 5 (30.4 g, 48 wt %) were combined and cooled to 0° C. Diethylaluminum chloride solution in toluene (1.8M, 29.3 mL) was added over 45 min, keeping the temperature below 5° C. (exothermic addition). The dark orange solution was aged at 0° C. for 18 h (˜90% conversion), and then at 21° C. for 6 h when it reached >95% conversion.
If the desired conversion was not achieved, more Lewis acid (and dimenthyl fumarate if necessary) could be added at any point of the reaction.
The reaction mixture was carefully quenched with aqueous 3 N HCl (8 mL) over >60 min while keeping the temperature at 15-25° C.
It is important to add this first portion of HCl very slowly without any bursts. Although the batch is not very sensitive to heat, rapid off-gassing and foaming upon addition of HCl could result in a disastrous overflow of the batch. The foaming needs to be watched very closely.
The remaining HCl (3N, 44.7 mL) was added slowly while keeping temperature at 15-25° C., and the resulting mixture was aged for 30 min at rt. The aqueous layer was removed, and the organic layer was washed with 1 N aq HCl (2×50 mL) and 0.5 N aq NaOH (50 mL). The toluene solution was used directly in the next step
The toluene solution from step 5 was concentrated to remove all solvents, flushed with acetonitrile, to give 210 mL slurry in acetonitrile. Aqueous 6 N HCl (6.2 mL) was added. The slurry was stirred at room temperature for ˜2 h, at which point HPLC indicated that the reaction was complete.
Add 22 L THF to a 100 L RBF with an inert atmosphere. Cool the flask to −40° C. and add L1(O-tBu)3AlH. Charge ketone 1 as a solid with a THF (3 L) rinse while keeping temp <−25° C. Stir at −30 to −35° C. until <5% starting material remains (all solid dissolves), approximately 2-3 hours. The trans/cis ratio is typically ˜25.
Warm the reaction mixture to ˜−20° C. and add LiAlH4. Allow the batch warm up to ˜10° C. and apply cooling to keep the temperature <30° C. Stir the reaction mixture at room temperature until observing complete reduction to the triol (<0.5% desired diol 1b left), >3 hours.
Cool the batch to ˜0° C. and reverse quench slowly into 6.0 N HCl (23.5 L) while keeping the temperature <40° C. Use 2 L THF to rinse the reaction vessel. Caution! Significant H2 off-gassing and exotherm will occur over the entirety. Two clear layers should form if settling occurs. Concentrate the quenched solution to ˜30 L (4.3V) (water starts to condense at this point).
Add heptane (35 L) followed by 6.0 L 6.0 N HCl and 8.9 L 12.0N HCl to dissolve a rag layer. Cut and keep the aqueous layer (˜40 L) (org layer ˜43 L), being certain to keep any rag (<250 mL) with the aqueous. Assay each layer to ascertain the menthol distribution, which should show <2% remaining in the aqueous. Charge the aq layer back to the extractor with 1 L water rinse. Titrate to pH ˜1.5-2 with ˜14 L 10N NaOH while keeping temperature <30° C. (charge 12 L first, followed by 0.5 L portions; pH is ˜0 after 13 L is charged; it could take ˜10-15 min for pH meter to give a stable pH reading.).
Add 39 L EtOAc and stir vigorously for 30 min. Make sure pH is ˜1.5-2, otherwise add 10 N NaOH or conc HCl in 250 mL portions to adjust the pH. Allow 1-2 h for the emulsion layer to break up. Cut and keep the aqueous (50 L), which should show ˜14% product remaining. Drum off the organic (41 L) followed by addition of collidine (35 mL) to adjust to pH ˜4-4.5. Repeat the extraction once more with 39 L EtOAc (faster settling this time). The aqueous layer should show ˜2% product remaining and is discarded.
Concentrate the combined organic layers and flush with EtOAc to ˜9 L with a KF<1000 ppm. Drum off with an inline filter with 3 L MeCN rinse. Expected yield: 2.91 kg of trans-triol (91% Y), 3.02 kg total triols (trans/cis ˜25). The resulting solution is stable at rt for >9 days and at 50° C. for >4 days.
Charge the triol solution (containing 4.34 kg active triol+0.23 kg of other triols and ˜8.7 L EtOAc+4 L MeCN, KF ˜2000 ppm, equiv 10 mol % H2O), MeCN (14 L) and n-PrSO2Cl to a 100 L extractor. Cool the solution to 15° C. and add collidine all in one portion. Apply cooling to keep the reaction temperature at 18-21° C. A slurry forms within 30 min.
After 230 min (2a+b: 120 min-14.4 A %, 180 min-4.6 A %, 210 min-1.4 A %, non-SM related peaks-collidine, EtOAc, n-PrSO2Cl-are not integrated), quench the reaction with 1 N HCl (21.6 L) and add 14 L more EtOAc The quench is slightly endothermic to ˜15° C. and then back to ˜18° C. Cut away the bottom aqueous layer (˜34 L). Wash the organic layer with 10% NaCl (38 L) combined with 50% v/v HCl (6.0 N, 0.50 L) to remove any residual collidine. Cut away the bottom aq layer (˜41 L) and add NaOH (1 N, 30 L, removing PrSO2Cl) to the organic layer while keeping temperature <27° C. Stir for 15 min and let the layers settle. Cut away the aq layer (˜36 L) and wash the organic layer, which should show <2 mol % of n-PrSO2Cl left, with 6% NaCl (20 L). Cut away the aq layer (˜24 L) and collect the organic layer (25.6 kg) with 1 L EtOAc rinse and assay for yield (6.80 kg 3.85%).
It is then concentrated to an oil, flushed with 20 L cyclohexane to an oil and then with 30 L CH2Cl2 to ˜10 L (transfer the solution to a new flask via an inline filter after 15 L CH2Cl2 is used and then continue the distillation), when KF should be <250 ppm and EtOAc<8 mol % by LC. The solution is used for the next reaction.
To a 100 Liter Flask containing 27 L of a 4:1 mixture of cyclohexane/CH2Cl2 was added 8.0 Kg of (S) BTBA as a solid and the sides of the flask were rinsed with an additional 10.3 L of 4:1 mixture of cyclohexane/CH2Cl2. To the resulting slurry was added 4.92 Kg (3.42 Liters) of trichloroacetonitrile followed by 92.2 mL of DBU. The reaction mixture was aged at rt for 5.5 h and assayed for completion. The reaction mixture was then transferred to a 100 Liter extractor rinsing the reaction flask with cyclohexane. The mixture was washed with 27 Liters of water and then with 27 liters of brine. The organic layer was then filtered over a small plug of Solka floc and azetropically distilled under reduced pressure (24 mmHg, internal temp<35° C.) and a final volume of ˜15 Liters and a Kf<200. Assay yield=12.00 Kg (96.2%).
Charge the CH2Cl2 solution of the cyclohexanol 3 (containing 6.73 kg active 3+˜0.78 kg of related other alcohols and ˜6 L CH2Cl2, KF<250 ppm, equiv <1.2 mol % H2O) to a 100 L extractor. Charge the imidate solution (˜850 g/L in cyclohexane, ˜11 L, containing ˜2 L cyclohexane) followed by additional cyclohexane (8.0 L). The mixture turns cloudy due to 3 oiling out. Add more CH2Cl2 (2 L) to dissolve the oil. Cool to −17° C. (oiling out at ˜0° C.) and add more CH2CL2 (1.3 L) to dissolve the oil. The KF at this point should be <110 ppm (<1.5 mol % water). Add 0.17 equiv of HBF4 (0.339 L) in one portion, resulting in temperature rising to −16° C. The slightly cloudy mixture is aged at −16° C. It turns clear in ˜40 min and a slurry starts to form and thickens as the reaction proceeds to generate poorly soluble trichloroacetamide A.
After aging at −16° C. for 18 hours, LC assay reveals ˜82% conv and a 5/5a ratio of ˜6. For slightly higher conversion, 0.11 equiv more HBF4 (0.219 L) is added following by aging at −16° C. for 4 h. The reaction is then warmed to 5° C. and aged for 1 h before being quenched with NaOH (2 N, 16 L). The exotherm brings the temperature to 18° C. After aging at rt for ˜15 min, the layers are allowed to settle. The bottom aqueous layer (˜18 L) is cut away and the organic layer is washed with 18 L of water. The cloudy bottom organic layer is collected (assay yield of 5: ˜74%), concentrated to ˜20 L, and flushed with IPA (90 L) while keeping batch temperature at ˜40° C. and volume at ˜50-60 L to enable stirring as the product crystallizes out. A final volume of ˜70 L is reached and the thick slurry is aged at rt until mother liquor shows <11 g/L loss (5/5a <0.55). The product is then filtered, washed with IPA (35 L), and dried. 7.07 kg, 98 A %, 96 wt %, 6.82 kg corrected, 67% yield.
Step 5: Cyclization with Allylamine
The reaction vessel was charged with IPA (27 L), allylamine (3.74 L, 50.0 moles), and bis-propylsulfonate (6.79 kg, 9.61 moles).
The reaction vessel was charged with THF (25.8 L), allylamine protected pyrrolidine (5.16 Kg, 10.0 moles), and thiosalicylic acid (1.62 Kg, 10.5 moles). The reaction mixture was degassed and dppb (4.3 g, 0.01 mol) was added followed by Pd2(dba)3 (4.6 g, 0.005 mol) under nitrogen. The mixture was stirred at +40° C. for 4 h, cooled to r.t and was reverse added into a stirred biphasic mixture made of MTBE (41 L) and 1 N aqueous NaOH solution (25.8 L). Layers were separated and the organic was washed with water (2×23 L). The organic solution was concentrated under vacuum with feeding of MTBE (in-line filtration w/1 □m) with a constant total volume of ca. 45 L to lower the KF to less than 5000 ppm.
A 100 liter flask was charged with IPA (26 L). To this was added the acetic acid salt (7.5 Kg) followed by 1,3-cyclopentanedione (1.51 Kg). The sides of the flask were washed with IPA (4 L) and the mixture is heated to +75° C. for 1 h at which point HPLC indicated that the reaction was complete. To the reaction mixture was then added 1/3 volume of water (10 L) keeping the temperature at +60° C. The batch was seeded (2.00 g, 0.02 wt %) to initiate crystallization. After aging at 50-60° C. for 30 min, the mixture was cooled to 40° C. The remaining water (26 L) was added over a period of 1.25 h and the slurry was aged for 12 hours at rt. The batch was filtered and the wet-cake was washed with 2 bed volumes of 2:1 Water/IPA and then 1 bed volume of water and dried overnight under vacuum/N2 sweep. The resulting wet cake was transferred to a vacuum over and further dried at 45° C. under vacuum with a sweep of nitrogen for 24 h to give 7.45 Kg of API (98% yield).
| Filing Document | Filing Date | Country | Kind | 371c Date |
|---|---|---|---|---|
| PCT/US2006/026293 | 7/7/2006 | WO | 00 | 12/18/2007 |
| Number | Date | Country | |
|---|---|---|---|
| 60698237 | Jul 2005 | US | |
| 60698761 | Jul 2005 | US |
