CN118265708A

CN118265708A - Method for separating enantiomers

Info

Publication number: CN118265708A
Application number: CN202280068632.4A
Authority: CN
Inventors: M·阿克马托维茨; S·库利克; D·斯尼德; C·陈; M·马克斯; C·史密斯
Original assignee: Mirati Therapeutics Inc
Current assignee: Mirati Therapeutics Inc
Priority date: 2021-10-06
Filing date: 2022-10-06
Publication date: 2024-06-28

Abstract

The present invention relates to a process for the separation of enantiomers of 5-phenyl and 5-naphthyl substituted 4- (aminomethyl) -6- (1-methyl-1H-pyrazol-4-yl) phthalazin-1 (2H) -one using N-Boc-L-phenylalanine, N-Boc-D-phenylalanine and similar chiral acids.

Description

Method for separating enantiomers

Cross Reference to Related Applications

The present application claims priority from U.S. provisional application No. 63/252,973, filed on 6 at 10 at 2021, and U.S. provisional application No. 63/352,504, filed on 15 at 6 at 2022, the disclosures of which are hereby incorporated by reference in their entireties.

Technical Field

Background

Certain 5-substituted 4- (aminomethyl) -6- (1-methyl-1H-pyrazol-4-yl) phthalazin-1 (2H) -ones, such as compounds 1 and 2 below, are axially chiral and thus exist as atropisomers. Compound 1, axial chiral 2- (4- (4- (aminomethyl) -1-oxo-1, 2-dihydro-phthalazin-6-yl) -1-methyl-1H-pyrazol-5-yl) -3-fluoro-3, 4-dihydro-naphthalene-1-carbonitrile, and compound 2, axial chiral 2- (4- (4- (aminomethyl) -1-oxo-1, 2-dihydro-phthalazin-6-yl) -1-methyl-1H-pyrazol-5-yl) -4-chloro-6-cyclopropoxy-3-fluorobenzonitrile, are potent and selective inhibitors of PRMT 5.

However, only the M-atropisomer of compound 2, which is described below and may be named as (2M) -2- (4- (4- (aminomethyl) -1-oxo-1, 2-dihydro-phthalazin-6-yl) -1-methyl-1H-pyrazol-5-yl) -4-chloro-6-cyclopropyloxy-3-fluorobenzonitrile (hereinafter referred to as compound M-2), has pharmacological activity.

The axial chirality in compounds 1 and 2 is the result of a limited rotation between the phenyl moiety (ring a) and the central N-methylpyrazole (ring B). The molecules sharing this ring a/ring B motif, comprising compound 1 and compound 2 and their upstream intermediates, are therefore present in the form of a mixture of resolvable enantiomers.

The pharmacologically active M-enantiomer of compound 2 may be obtained by chiral chromatography. The specific optical rotation of this compound was [ αd=35° (c=0.3, meoh) when measured at 25 ℃ using a material with an enantiomeric excess of 97.3% of the (M) enantiomer.

The synthesis to give racemic compound 2 is described in published International application WO2021/050915A1 (published at month 18 of 2021, incorporated herein by reference). See racemic compounds 4-230 at page 243; coupling methods 4D at pages 195-196 and purification methods 4-6 at page 198. The M-enantiomer and the P-enantiomer of the racemic compound 2 thus synthesized were separated as described in examples 16-7 and 16-8 on page 307 in WO2021/050915A 1. This chiral chromatographic separation process is disadvantageous because it is solvent intensive, non-scalable and expensive.

In view of the above drawbacks, alternative methods of synthesizing pure or highly enriched M-enantiomer of compound 1 and compound 2 were sought.

Enantioselective variants of Suzuki-Miyaura cross-coupling reactions (coupling reaction) are considered, but this is considered not viable due to at least two major challenges: (1) The heavy ortho-substituted building blocks required for the suzuki-miyaura reaction are difficult to cross-couple even in the racemic manner, and (2) the elevated temperatures required for the suzuki-miyaura reaction are incompatible with compound 2 due to accelerated racemization under these conditions.

Because the known methods of synthesizing the M-enantiomer of compound 2 are neither efficient nor scalable, and because the enantioselective changes of theoretically alternative methods, such as the bell wood-palace cross-coupling reaction, are excluded from being viable, there is a need for improved, efficient methods to obtain the M-enantiomer of compound 2, i.e., compound M-2.

Disclosure of Invention

The present invention comprises resolution of racemic compound 2 using chiral acids according to the following scheme:

Although many chiral acids were tested, the inventors were initially unable to identify salts that adequately differentiated between the M-and P-enantiomers of compounds 1 and 2. It was then unexpectedly found that salt formation and certain chiral acids (HA ^*), in particular N-Boc-L-phenylalanine and N-Boc-D-phenylalanine, between the M-enantiomer and the P-enantiomer component of the free base of racemic compound 1 and compound 2, produced two diastereomeric salts (M-A ^* and P-A ^*). In contrast to the individual enantiomers, the resulting salts of compound 1 and compound 2 surprisingly have different physicochemical properties, such as different solubilities or crystallinity. After finding chiral acid HA ^* (N-Boc-L-phenylalanine and/or N-Boc-D-phenylalanine) to be suitable, resolution of the racemate can be determined by either of two scenarios: in scenario a, the desired compound 2 salt enantiomer (M-a ^*) is less soluble and therefore crystallises preferentially, providing a solid enriched in M-a ^*, whereas the undesired compound 2 salt diastereomer (P-a ^*) is rejected in the supernatant. In scenario B, the undesired compound 2 salt diastereomer (P-a ^*) is less soluble and preferentially crystallizes, thus enriching the supernatant in compound 2 salt M-a ^*.

The present invention also provides salts of compound 1 and compound 2. Specifically, the present invention provides the following

(2M) -2- (4- (4- (aminomethyl) -1-oxo-1, 2-dihydro-phthalazin-6-yl) -1-methyl-1H-pyrazol-5-yl) -3-fluoro-3, 4-dihydro-naphthalene-1-carbonitrile N-Boc-D-phenylalanine salt;

(2P) -2- (4- (4- (aminomethyl) -1-oxo-1, 2-dihydro-phthalazin-6-yl) -1-methyl-1H-pyrazol-5-yl) -3-fluoro-3, 4-dihydro-naphthalene-1-carbonitrile N-Boc-D-phenylalanine salt;

(2M) -2- (4- (4- (aminomethyl) -1-oxo-1, 2-dihydro-phthalazin-6-yl) -1-methyl-1H-pyrazol-5-yl) -3-fluoro-3, 4-dihydro-naphthalene-1-carbonitrile N-Boc-L-phenylalanine salt;

(2P) -2- (4- (4- (aminomethyl) -1-oxo-1, 2-dihydro-phthalazin-6-yl) -1-methyl-1H-pyrazol-5-yl) -3-fluoro-3, 4-dihydro-naphthalene-1-carbonitrile N-Boc-L-phenylalanine salt;

(2M) -2- (4- (4- (aminomethyl) -1-oxo-1, 2-dihydro-phthalazin-6-yl) -1-methyl-1H-pyrazol-5-yl) -4-chloro-6-cyclopropyloxy-3-fluorobenzonitrile, N-Boc-D-phenylalanine salt;

N-Boc-D-phenylalanine salt of (2P) -2- (4- (4- (aminomethyl) -1-oxo-1, 2-dihydro-phthalazin-6-yl) -1-methyl-1H-pyrazol-5-yl) -4-chloro-6-cyclopropyloxy-3-fluorobenzonitrile

(2M) -2- (4- (4- (aminomethyl) -1-oxo-1, 2-dihydro-phthalazin-6-yl) -1-methyl-1H-pyrazol-5-yl) -4-chloro-6-cyclopropyloxy-3-fluorobenzonitrile, N-Boc-L-phenylalanine salt; and

N-Boc-L-phenylalanine salt of (2P) -2- (4- (4- (aminomethyl) -1-oxo-1, 2-dihydro-phthalazin-6-yl) -1-methyl-1H-pyrazol-5-yl) -4-chloro-6-cyclopropyloxy-3-fluorobenzonitrile.

The present invention still further encompasses crystalline forms of the above-mentioned Boc-phenylalanine salt in solid form, in particular the N-Boc-D-phenylalanine salt of (2M) -2- (4- (4- (aminomethyl) -1-oxo-1, 2-dihydro-phthalazin-6-yl) -1-methyl-1H-pyrazol-5-yl) -4-chloro-6-cyclopropyloxy-3-fluorobenzonitrile.

The present invention also encompasses crystalline forms of (2M) -2- (4- (4- (aminomethyl) -1-oxo-1, 2-dihydro-phthalazin-6-yl) -1-methyl-1H-pyrazol-5-yl) -4-chloro-6-cyclopropyloxy-3-fluorobenzonitrile and (2M) -2- (4- (4- (aminomethyl) -1-oxo-1, 2-dihydro-phthalazin-6-yl) -1-methyl-1H-pyrazol-5-yl) -4-chloro-6-cyclopropyloxy-3-fluorobenzonitrile hydrochloride. More specifically, the present invention provides a crystalline form of (2M) -2- (4- (4- (aminomethyl) -1-oxo-1, 2-dihydro-phthalazin-6-yl) -1-methyl-1H-pyrazol-5-yl) -4-chloro-6-cyclopropyloxy-3-fluorobenzonitrile, i.e. crystalline form a of compound M-2. The present invention also provides crystalline form a and crystalline form B of (2M) -2- (4- (4- (aminomethyl) -1-oxo-1, 2-dihydro-phthalazin-6-yl) -1-methyl-1H-pyrazol-5-yl) -4-chloro-6-cyclopropyloxy-3-fluorobenzonitrile hydrochloride.

The invention also provides a system for generating and separating: crystalline forms of (2M) -2- (4- (4- (aminomethyl) -1-oxo-1, 2-dihydro-phthalazin-6-yl) -1-methyl-1H-pyrazol-5-yl) -4-chloro-6-cyclopropyloxy-3-fluorobenzonitrile hydrochloride and (2M) -2- (4- (4- (aminomethyl) -1-oxo-1, 2-dihydro-phthalazin-6-yl) -1-methyl-1H-pyrazol-5-yl) -4-chloro-6-cyclopropyloxy-3-fluorobenzonitrile hydrochloride, in particular crystalline form a of (2M) -2- (4- (4- (aminomethyl) -1-oxo-1, 2-dihydro-phthalazin-6-yl) -1-methyl-1H-pyrazol-5-yl) -4-chloro-6-cyclopropyloxy-3-fluorobenzonitrile hydrochloride.

Drawings

FIG. 1 is a flow chart showing the separation of highly enriched or pure compound M-2 as described in examples 1A and 1B as a solid.

FIG. 2 is a flow chart showing the separation of highly enriched or pure compound M-2 in the liquid phase as described in example 2.

Fig. 3 is a diagram of a system including a crystallization module and an epimerization module according to the invention.

Fig. 4 is a 1H qNMR analysis according to an example embodiment.

FIG. 5 is an HPLC chromatogram of R-BINOL according to an example embodiment.

FIG. 6 is an HPLC chromatogram of S-BINOL according to an example embodiment.

Fig. 7 is an HPLC chromatogram of the supernatant after aging for 1 hour according to an example embodiment.

Fig. 8 is an HPLC chromatogram of an eluate from flash epimerization at t=0, according to an example embodiment.

FIG. 9 is an HPLC of crystallized R-BINOL according to an example embodiment.

FIG. 10 is ¹ H NMR of the compound M-2 Boc-D-phenylalanine in D ₆ -DMSO according to an example embodiment.

FIG. 11 is a graph showing the rapid equilibration achieved using MSMPR-SPACE combinations.

Fig. 12 is a diagram of a system including a crystallization module (MSMPR), a collection module or tank, and a racemization or epimerization module according to the present invention. In the course of this drawing the drawing is,Represents the M-enantiomer in solution,Represents the P-enantiomer in solution,Represents the M-enantiomer in the crystalline phase,Indicating the application of heating, andIndicating the application of cooling.

Fig. 13 is a graph showing a distribution ratio in a solid (D _s) according to an example embodiment.

Detailed Description

As used herein, the term "atropisomer" refers to stereoisomers that exist as a result of a hindered rotation about a single bond. In such compounds, the energy differences due to spatial strain or other factors create a sufficiently high rotational barrier to allow separation of the individual conformations.

As used herein, the compound M-1 refers to (2M) -2- (4- (4- (aminomethyl) -1-oxo-1, 2-dihydro-phthalazin-6-yl) -1-methyl-1H-pyrazol-5-yl) -3-fluoro-3, 4-dihydro-naphthalene-1-carbonitrile, i.e., a compound having the following structure

As used herein, the compound P-1 refers to (2P) -2- (4- (4- (aminomethyl) -1-oxo-1, 2-dihydro-phthalazin-6-yl) -1-methyl-1H-pyrazol-5-yl) -3-fluoro-3, 4-dihydro-naphthalene-1-carbonitrile, i.e., a compound having the following structure

As used herein, the compound M-2 refers to (2M) -2- (4- (4- (aminomethyl) -1-oxo-1, 2-dihydro-phthalazin-6-yl) -1-methyl-1H-pyrazol-5-yl) -4-chloro-6-cyclopropyloxy-3-fluorobenzonitrile, i.e., a compound having the following structure

As used herein, the compound P-2 refers to (2P) -2- (4- (4- (aminomethyl) -1-oxo-1, 2-dihydro-phthalazin-6-yl) -1-methyl-1H-pyrazol-5-yl) -4-chloro-6-cyclopropyloxy-3-fluorobenzonitrile, i.e., a compound having the following structure

Identifying a suitable chiral acid (HA ^*) that is capable of providing a sufficiently large distinction (in terms of physical or chemical properties) between the M-enantiomer and the P-enantiomer of compound 1 and compound 2 is challenging, probably due to the spatial separation between the chiral axis and the chiral counter-ion, as shown below for compound M-2:

extensive testing of a variety of chiral acids with compound 1 and compound 2 resulted in minimal upgrades in the solids or supernatant. For example, see table 1, where the enantiomer composition of compound 2 versus solids is shown to be in the range of 40% -60% to 60% -40% for most of the acids tested. However, it was unexpectedly found that certain chiral acids provided promising differentiation. For example, in certain embodiments, N-Boc-L-phenylalanine provides 79% -21% differentiation between the P-enantiomer and the M-enantiomer of compound 2, and N-Boc-D-phenylalanine provides 7% -93% and 2% -98% differentiation, depending on the solvent (see table 1, bottom).

TABLE 1

Enantiomer composition of precipitate obtained in chiral acid screening of Compound 2

More specifically, N-Boc-L-phenylalanine in THF as solvent produced a significant increase in the undesired P-enantiomer of compound 2 (P/m=79/21, 58% diastereomeric excess (de)) compared to other chiral acids. Similar salt formation/crystallization experiments with N-Boc-D-phenylalanine provided enrichment of the M-enantiomer of compound 2 (P/m=7/93, 86% de). This finding led to the development of two complementary methods for separating the M-enantiomer of compound 2 from the racemate: N-Boc-D-phenylalanine was used by enrichment of solids (FIG. 1); and N-Boc-L-phenylalanine was used by enrichment in the supernatant (FIG. 2).

In certain aspects of the invention, the undesired P-enantiomer isolated during resolution may be recycled to provide additional enantiomerically enriched M-enantiomer of compound 2. The procedure outlined in the schemes below describes this method using the P-enantiomer of the compound 2 Boc-D-phenylalanine salt as an input, however the compound P-2 Boc-L-phenylalanine salt is also suitable. Without being bound by theory, it is believed that this process exploits the thermal conformational instability of the atropisomers that accelerates racemization at high temperatures. Thus, in certain embodiments, the partially enriched mixture in the P-enantiomer of compound 2 (e.g., P/m=85/15) may be racemized (e.g., P/m=49/51) to provide additional M-enantiomer for the resolution step. The procedure directly epimerizes the P-enantiomer compound 2 Boc-D-phenylalanine salt for convenient enantiomer separation after cooling.

This procedure can be used to continuously recycle the undesired enantiomer to yield the additional desired M-2 enantiomer. Thus, for example, the recycling of the undesired P-2 enantiomer may comprise

(A) Forming a solvent, such as an aqueous ethanol solution, a mixture of M-2, P-2 and Boc-D-phenylalanine, in a crystallization vessel to form a compound M-2 Boc-D-phenylalanine salt and a compound P-2 Boc-D-phenylalanine salt;

(b) Forming a solid phase and a liquid phase in the mixture, wherein the solid phase contains an enantiomeric excess of the compound M-2 Boc-D-phenylalanine salt and the liquid phase contains an enantiomeric excess of the compound P-2 Boc-D-phenylalanine salt;

(c) Filtering a portion of the liquid phase;

(d) Subjecting the filtered liquid phase fraction to conditions sufficient to produce an increased amount of compound M-2 Boc-D-phenylalanine salt in the filtered liquid phase relative to the amount of the salt in the liquid phase in (b);

(e) Returning the filtered liquid phase produced in (d) to the crystallization vessel; and

(F) Crystals of the compound M-2 Boc-D-phenylalanine salt were isolated.

In this procedure, if a solid phase is not formed in (b) without cooling, the process may comprise adjusting the temperature of the mixture from (a) to a temperature at which the compound M-2 Boc-D-phenylalanine salt and the compound P-2 Boc-D-phenylalanine salt have different solubilities.

It was also surprisingly found that the N-Boc-L-phenylalanine and N-Boc-D-phenylalanine of the M-enantiomer and the P-enantiomer of compound 1 show different solubilities.

In addition to isolating atropisomers of compound 2, the methods disclosed herein can be readily used to isolate atropisomers of other compounds, including biologically active compounds and intermediates useful in the preparation of such biologically active compounds. Specific examples of compounds that exist as atropisomers and that can be used in the methods disclosed herein include [1,1 '-binaphthyl ] -2,2' -diol and 6-fluoro-7- (2-fluoro-6-hydroxyphenyl) - (1M) -1- [ 4-methyl-2- (prop-2-yl) pyridin-3-yl ] -4- [ (2S) -2-methyl-4- (prop-2-enoyl) piperazin-1-yl ] pyrido [2,3-d ] pyrimidin-2 (1H) -one and synthetic intermediates useful in preparing such compounds.

In certain aspects, the invention provides a method (example a) of separating a mixture of atropisomers, wherein the method comprises:

(a) Forming a mixture of solvent, first atropisomer and second atropisomer in a crystallization vessel;

(b) Producing a liquid phase and a solid phase by adjusting the temperature of the mixture to a temperature at which the first atropisomer and the second atropisomer have different solubilities, if necessary, wherein the solid phase contains an enantiomeric excess of the first atropisomer and the liquid phase contains an enantiomeric excess of the second atropisomer;

(c) Withdrawing a portion of the liquid phase;

(d) Subjecting the withdrawn liquid phase fraction to conditions sufficient to produce an increased amount of the first atropisomer in the withdrawn liquid phase relative to the amount in the liquid phase in (b);

(e) Returning the withdrawn liquid phase produced in (d) to the crystallization vessel; and

(F) Separating the crystals of the first atropisomer.

In certain aspects, depending on the temperature of the vessel, solvent, and starting material, and the choice of solvent, the atropisomers with lower solubility will crystallize without cooling or seeding. Cooling and/or seeding may be employed to produce solid and liquid phases, if necessary.

In certain aspects of example A, the atropisomer is a compound having formula I (example B)

Wherein the method comprises the steps of

Ring A is

Wherein the connection point of the bicyclic ring a and the ring B is located on ring E;

The B ring is a 6-10 membered aryl, a 5-10 membered heteroaryl, a 5-10 membered heterocycloalkyl, an amido, a sulfone, sulfoxide, an alkene, an amine or an ether group, each of which is optionally substituted;

Z is N, CH or CR ¹;

n is 0, 1, 2, 3 or 4;

x is 0, 1 or 2;

m is 0, 1, 2, 3 or 4;

Each R ¹ is independently C ₁-C₆ alkyl, C ₁-C₆ alkoxy, C ₃-C₈ cycloalkyl, C ₃-C₈ cycloalkoxy, halogen, cyano, hydroxy, amino, or mono or di C ₁-C₆ alkylamino; and

Each R ² is independently C ₁-C₆ alkyl, C ₁-C₆ alkoxy, C ₃-C₈ cycloalkyl, C ₃-C₈ cycloalkoxy, halogen, cyano, hydroxy, amino, or mono or di C ₁-C₆ alkylamino;

Provided that at least one of the positions on the a-ring that are ortho to the point of attachment of the a-ring and the B-ring is substituted with R ¹.

In a particular embodiment of embodiments a and B (embodiment C), the withdrawing, the subjecting, and the returning are continued until the amount of the second atropisomer in the liquid phase is below a predetermined level (embodiment C).

In a particular embodiment of embodiments a-C (embodiment D),

The mixture of the solvent, the first atropisomer, and the second atropisomer further includes a resolving agent that forms a first atropisomer-resolving agent complex and a second atropisomer-resolving agent complex in the mixture; and

The method further comprises subjecting the crystals of the first atropisomer-resolving agent complex to conditions capable of separating the first atropisomer from the first atropisomer-resolving agent complex.

In a particular embodiment of embodiments a-D (embodiment E), the first atropisomer is (2M) -2- (4- (4- (aminomethyl) -1-oxo-1, 2-dihydro-phthalazin-6-yl) -1-methyl-1H-pyrazol-5-yl) -4-chloro-6-cyclopropyloxy-3-fluorobenzonitrile (compound M-2), and the second atropisomer is (2P) -2- (4- (4- (aminomethyl) -1-oxo-1, 2-dihydro-phthalazin-6-yl) -1-methyl-1H-pyrazol-5-yl) -4-chloro-6-cyclopropyloxy-3-fluorobenzonitrile (compound P-2).

In a specific embodiment of embodiments a-E (embodiment F), the mixture of the solvent, the first atropisomer, and the second atropisomer further comprises a resolving agent that is N-Boc-D-phenylalanine.

In a particular embodiment of embodiments a-F (embodiment G), the solvent is MeOH or an aqueous MeOH solution.

In a particular embodiment of embodiments a-F (embodiment H), the solvent is EtOH or an aqueous EtOH solution.

In a particular embodiment of embodiments A-F (embodiment I), the solvent is EtOH/water from about 85:15 (v/v) to about 99:1 (v/v).

In a specific embodiment of embodiments a-I (embodiment J), the adjusting in (b) is to a temperature of about 20-25 ℃.

In a particular embodiment of embodiments a-J (embodiment K), the subjecting in (d) comprises heating at a temperature of about 80-200 ℃.

Specific B-ring heteroaryl groups in formula I include triazolyl, pyrazolyl, and imidazolyl.

Specific B-ring heterocycloalkyl groups in formula I include pyrimidinyl, pyridinyl, piperazinyl, piperidinyl, morpholinyl, pyrrolidinyl, tetrahydropyranyl, 2-oxopyrido [2,3-d ] pyrimidin-1 (2H) -yl, 2-oxo-3, 4-dihydro-1, 8-naphthyridin-1 (2H) -yl, and 7-oxo-5, 6,7, 8-tetrahydroquinolin-8-yl.

The particular B-ring aryl in formula I comprises phenyl and naphthyl, each of which is optionally substituted with one or more of C ₃-C₆ alkyl, hydroxy, cyano, or halogen.

The particular A ring group in formula I comprises a phenyl, pyridinyl, naphthyl substituted with C ₃-C₆ alkyl, hydroxy, cyano, or halo in at least one ortho position relative to the point of attachment to the B ring.

The generic abbreviations used herein include:

e. -enantiomer excess

D.e. -diastereomeric excess

R. enantiomer ratio

R. diastereomer ratio

SFC-supercritical fluid chromatography

SPPS-solid phase peptide synthesis

Boc-tert-Butoxycarbonyl group

DCM-dichloromethane

EtOAc-ethyl acetate

EtOH-ethanol

IPA, i-PrOH-propan-1-ol, isopropanol

MeCN-acetonitrile

MeOH-methanol

Phe-phenylalanine

D-Phe-D-phenylalanine

L-Phe-L-phenylalanine

THF-tetrahydrofuran

Thus, in one embodiment of the invention (example L), there is provided a method of separating a mixture of M enantiomer and P enantiomer of compound 2, the method comprising the steps of: (a) Contacting the mixture with N-Boc-D-phenylalanine to form a mixture of M-enantiomer N-Boc-D-phenylalanine salt and P-enantiomer N-Boc-D-phenylalanine salt; (b) Filtering the mixture to obtain a solid phase enriched in the N-Boc-D-phenylalanine salt of the M-enantiomer; and (c) reacting the solid phase with excess NH ₃ or other base to obtain a solid enriched in M-enantiomer free base compound 2.

Alcohol solvents include, but are not limited to, alcohols having 1 to 6 carbon atoms, including methanol (MeOH), ethanol (EtOH), n-propanol, isopropanol, n-butanol, 2-butanol, t-butanol, n-pentanol, 2-pentanol, 3-pentanol, n-hexanol, and the like. In certain such embodiments, the contacting in step (a) occurs in MeOH or an aqueous MeOH solution. Suitable aqueous methanol mixtures have up to about 25% water by volume.

In certain such embodiments, the contacting in step (a) occurs in EtOH or an aqueous EtOH solution. Suitable aqueous ethanol mixtures for batch processing have up to about 30% by volume water. A preferred aqueous ethanol mixture for batch processing is about 90:10 (v/v) ethanol/water. For continuous or semi-continuous treatment, ethanol with 0-15% (v/v /) water is preferred, ethanol with 0-10% (v/v /) water is more preferred, and ethanol with 0-5% water is particularly preferred.

In certain embodiments, the contacting in step (a) occurs in neat THF or THF/alcohol, e.g., in a volume ratio of THF/EtOH of 10:1, 9:1, 8:1, 7:1, 6:1, 5:1, 4:1, or 3:1.

In certain such embodiments, the solid phase obtained in step (b) is washed one or more times with additional solvent to remove the P-enantiomer N-Boc-D-phenylalanine salt.

In certain such embodiments, the reaction of step (c) occurs in isopropyl alcohol solution (IPA, i-prah) or in isopropyl alcohol and water. An aqueous mixture of IPA-water (e.g., 90/10 v/v) is preferred to maximize recovery and control of the API form. The desired API form (free base form A) is most stable at water activities of a _w > 0.13. In certain embodiments, the solution of step (c) is optionally inoculated with M-enantiomer free base compound 2.

In certain embodiments, the enriched solid obtained in step (c) is obtained by filtering the reaction mixture after precipitation of M-enantiomerically enriched free base compound 2.

In certain embodiments, the filtered M-enantiomer enriched free base compound 2 precipitate is purified by an additional slurry or washing step designed to remove residual N-Boc-D-phenylalanine.

In a particular embodiment of embodiment L (embodiment M), the contacting produces a slurry comprising

A solid phase enriched in the M-2N-Boc-D-phenylalanine salt of said compound, and

Enriching the liquid phase of the compound P-2N-Boc-D-phenylalanine salt; and

The method further comprises

Separating a portion of the liquid phase from the slurry, and

Heating the liquid phase to produce a heated mixture having a different ratio of compound P-2N-Boc-D-phenylalanine salt to compound M-2N-Boc-D-phenylalanine salt than before the heating.

In a particular embodiment of embodiment M (embodiment N), the ratio after heating is about the ratio of the racemic mixture of the compound M-2N-Boc-D-phenylalanine salt to the compound P-2N-Boc-D-phenylalanine salt.

In a particular embodiment of embodiment M or embodiment N (embodiment O), the method further comprises cooling the heated mixture to produce a cooled mixture comprising a solid phase enriched in the compound M-2N-Boc-D-phenylalanine salt and a liquid phase enriched in the compound M-2N-Boc-D-phenylalanine.

In a particular embodiment of embodiment O (embodiment P), the cooling of the heated mixture includes combining the heated mixture with the slurry.

In certain embodiments, the filtrate from step (b) enriched in the P-compound 2N-Boc-D-phenylalanine salt is used to obtain a racemic or nearly racemic mixture of the P-and M-compounds 2N-Boc-D-phenylalanine. Typically, this is done by heating the filtrate to induce racemisation. Racemization may be followed by precipitation of the compound M-2N-Boc-D-phenylalanine salt under favourable solvent conditions.

In another embodiment of the present invention, there is provided a method of separating a mixture of the M-compound 2 enantiomer and the P-compound 2 enantiomer, the method comprising the steps of: (a) Contacting the mixture with N-Boc-L-phenylalanine to form a mixture of M-enantiomer N-Boc-L-phenylalanine salt and P-enantiomer N-Boc-L-phenylalanine salt; (b) Filtering the solid phase to obtain a liquid phase enriched in the M-enantiomer N-Boc-L-phenylalanine salt; and (c) reacting the N-Boc-L-phenylalanine salt of the M-enantiomer with a base to obtain the free base compound 2 enriched in the M-enantiomer.

In certain such embodiments, the contacting in step (a) occurs in EtOH or EtOH/water solvent.

In certain such embodiments, the contacting in step (a) occurs in MeOH or MeOH/water solvent.

In certain such embodiments, the contacting in step (a) occurs in THF or THF/water solvent.

In certain such embodiments, the aqueous phase obtained in step (b) is concentrated to dryness to obtain a solid M enantiomer enriched in the N-Boc-L-phenylalanine salt.

In certain such embodiments, the reacting step (c) occurs in a suspension of water and methylene chloride.

In certain such embodiments, the reacting step (c) occurs in addition to the suspension of water and methylene chloride.

In certain embodiments, the enriched M-enantiomer free base compound 2 obtained in step (c) is slurried with, for example, dichloromethane and filtered to remove the racemic free base compound 2, so as to obtain a further enriched M-enantiomer free base compound 2 in solution.

In certain embodiments, the further enriched M-enantiomer free base compound 2 solution is concentrated to obtain a solid further enriched M-enantiomer free base compound 2.

In another embodiment, the invention provides a system for separating atropisomers, the system comprising a crystallization module, an epimerization module, and a collection module.

In a particular embodiment of the system, the crystallization module is in fluid connection with the epimerization module via a take-off channel and a return channel.

In certain embodiments of the system, the take-off channel comprises the collection module, the collection module is fluidly and directly connected with the epimerization module and the crystallization module, and the return channel is fluidly and indirectly connected with the crystallization module and the epimerization module.

In other particular embodiments of the system, material is continuously or semi-continuously withdrawn from the crystallization module and fed directly or indirectly into the epimerization module, and material is at least semi-continuously returned from the epimerization module to the crystallization module.

The invention further provides a process for separating atropisomers, the process comprising

Selectively crystallizing the less soluble atropisomer in a crystallization module; and

Epimerization of the more soluble atropisomer in an epimerization module;

wherein soluble material is provided directly or indirectly from the crystallization module to the epimerization module continuously or semi-continuously and material from the epimerization module is returned at least semi-continuously to the crystallization module.

In a particular embodiment, the selectively crystallizing comprises introducing a solvent and a mixture of a first atropisomer and a second atropisomer into the crystallization module, wherein the first atropisomer and the second atropisomer have different solubilities in the solvent, and optionally adjusting the temperature to crystallize the less soluble atropisomer.

In a particular embodiment, the system includes a crystallization module (crystallizer) between the epimerization module (racemate) and the collection module or tank. See fig. 12. This arrangement can significantly reduce the time required to reach equilibrium. See fig. 11. Feeding the racemic stream from the epimerization module (racemizer) directly into the crystallization module (MSMPR vessel (mixed slurry mixed product reactor)) allows the resolution process to be operated in the crystallizer in the most desirable scheme. See fig. 13. Without being bound by a particular theory, it is believed that crystallization kinetics are improved because the process is operated at the highest achievable supersaturation of the desired diastereoisomer. In addition, since crystallization occurs in the tightly racemic supernatant, lattice substitution with the undesired diastereoisomer is minimized, resulting in highly diastereoisomeric pure crystals (fig. 13).

In particular embodiments, the epimerization comprises subjecting the more soluble atropisomer to conditions sufficient to produce an increased amount of the less soluble atropisomer.

Examples

The following examples are intended to further illustrate certain embodiments of the invention and are not intended to limit the scope of the invention.

Example 1A: method for increasing the proportion of the solid phase M-enantiomer of Compound 2 Using Boc-D-phenylalanine

A mixture of EtOH (700 mL) and water (80 mL) was prepared in a four-necked round bottom flask at 23 ℃. Racemic compound 2 (65.0 g,140mmol,1.00 eq.) and Boc-D-Phe-OH (39.4 g,153.8mmol,1.1 eq.) were charged to the flask and the mixture was stirred at ambient temperature. After about 15 minutes, most of the solids dissolved to produce a pale yellow suspension. Stirring was continued at 20-25 ℃ for 16 hours, during which time the reaction mixture gradually became a viscous white slurry. A sample of the suspension was removed and filtered (filter cake: 84.0% e.e.; filtrate: -70.0% e.e.). The reaction mixture was filtered at 20-25 ℃ and the filter cake was washed with EtOH (130 mL) to give 66.5g of a white wet solid (filter cake: 92.8% e.e.; filtrate: -75.7% e.e.). The wet cake was resuspended in a mixture of EtOH (300 mL) and water (55 mL) at 23℃and stirred at 20-25℃for 18 hours. Samples of the suspension were removed and filtered (filter cake: 97.1% e.e.; filtrate: 60.7% e.e.). The slurry was filtered at 20-25 ℃ and the filter cake was washed with EtOH (60 mL) to give 46.5g of a white wet solid (97.5% e.e., 84.1% w/w,38.3% assay yield by Q-NMR).

Example 1B: a process for the free basification of the M-enantiomer of the compound 2 Boc-D-phenylalanine salt to obtain the free base compound M-2 (free base type a).

A mixture of THF (45 mL) and water (15 mL) was prepared in a four-necked round bottom flask at 23 ℃. Compound 2Boc-D-Phe salt (10 g,97.5% e.e., 84.1% w/w as measured by Q-NMR) was added and dissolved to give a clear pale yellow solution. Another 1L four-necked round bottom flask was charged with H ₂ O (390 mL) and aqueous NH ₃ (25% w/w,10 mL). A solution of salt in THF in water was added dropwise to a 1L four-necked round bottom flask. A white solid gradually formed during the addition. The resulting suspension was stirred for 17 hours under 20-25 who said. The slurry was filtered at 20-25 ℃ and the filter cake was washed with water (2 x 40 ml) to give 9.36g of a white wet cake. The wet cake was reslurried in an IPA/water (10/90 v/v,80 mL) mixture at 20-25℃for 3 hours and filtered. The filter cake was dried at 45 ℃ for 12 hours to give 5.70g of a white solid (99.9% HPLC purity, 97.5% e.e., by KF,5.80% water, 91.7% w/w by Q-NMR, free base form a by XRD, 91.7%,97.8% isolated yield).

Example 2: method for increasing the ratio of M-enantiomer of Compound 2 in supernatant Using Boc-L-phenylalanine

Compound 2, racemic free base (1.8 g,3.9 mmol) and Boc-L-Phe (1.03 g,3.9 mol) were placed in a 100mL glass vessel. To this mixture was added EtOH/water (90/10 v/v,30 mL) at 25 ℃. The resulting slurry was stirred using an overhead stirrer at 350rpm at 25 ℃. During the first 15 minutes, the solid material was dissolved, resulting in a cloudy solution. The reaction mixture was stirred for a further 24 hours at 20 ℃ during which time a viscous milky slurry was obtained. The reaction mixture was filtered. The undesired enantiomer (about 75% of the total enantiomer) was rejected in the solid as the compound P-2Boc-L-Phe salt (-92% e.e.), and the desired enantiomer was enriched in the filtrate as the compound M-2Boc-L-Phe salt (68% e.e.). The filtrate was rotary evaporated to dryness under reduced pressure at 35 ℃ to give the crude salt as a pale yellow solid. The resulting crude salt was free-basified using a mixture of water (30 mL) and DCM (30 mL) containing enough saturated Na ₂CO₃ to obtain a pH between 8-10. The mixture was stirred at 25℃for 4 hours. The organic layer was separated using a separatory funnel and rotary evaporated to dryness at 35 ℃ under reduced pressure to give partially upgraded compound M-2 (1.00 g,68% e.e.,97% LC purity) as a pale yellow poorly crystalline solid. The enantiomeric purity of the free base was further improved by slurry conditioning in DCM. The solid was resuspended in DCM (20 mL) and stirred at 25℃for about 72 hours. The remaining solid was filtered off and confirmed to be the near racemic compound 2 (10% e.e.). The filtrate was concentrated to give upgraded compound M-2 (0.72 g,94% e.e.,39% yield).

Example 3: process for recovering the P-enantiomer of a compound 2 Boc-D-phenylalanine salt stream

A first aqueous EtOH filtrate (100 g,3.9g free base assay, -65.4% e.e.) from the resolution method described in example 1A was charged to a four-necked round bottom flask. The solution was heated at 70-80 ℃ for 60 hours to racemize the salt. The resulting nearly racemic mixture (-6.0% e.e.) was combined with the remaining liquid stream from the resolution process described in example 1A (50 g,1.3g free base assay, 40.6% e.e.;25g,0.5g free base assay, 63.0% e.e.) and concentrated to about 30mL under reduced pressure at 30-45 ℃. EtOH (50 mL) was added and the mixture distilled to about 30mL. This operation is repeated once more. EtOH (50 mL) was added and the mixture stirred at 70-75 ℃ for 0.5 hours. The mixture was cooled to room temperature to initiate crystallization of the compound M-2Boc-D-Phe salt. The resulting suspension was aged at 20-25 ℃ until no additional supersaturation was observed by measuring the supernatant. The reaction mixture was filtered and the resulting filter cake was washed with EtOH (10 mL) and dried to give 3.13g of compound M-2Boc-D-Phe salt as a white solid (99.8% LC purity, 96.0% e.e., 97.4% w/w,35% isolated yield by Q-NMR).

Example 4

The higher intermediates Int _AB and Int _CD were coupled using a palladium catalyzed suzuki-miyaura reaction to give a racemic mixture of Boc protected species. The desired M-enantiomer Boc protected species was separated from the undesired P-enantiomer using preparative chiral chromatography. The final compound 2M-enantiomer product was obtained after acid-promoted removal of the Boc protected group. This chiral chromatographic separation process is disadvantageous because it is solvent intensive, non-scalable and expensive.

Coupling: to a mixture of Int _AB (200G, 479mmol,1.00 eq), int _CD (231G, 575mmol, 1.2 eq.) and K ₃PO₄ in water (1.5M, 958mL,3 eq.) in dioxane (1.80L) was then added Ad ₂ -N-Pd-G3 (24.4G, 33.5mmol,0.07 eq.) under N ₂. The mixture was stirred at 80℃under N ₂ for 16 hours. The mixture was cooled to room temperature, then poured into ice water (2.00L) and stirred for 30 minutes. The aqueous phase was extracted with ethyl acetate (2 x 1.00 l). The combined organic phases were washed with brine (1.00L), dried over anhydrous Na ₂SO₄, filtered and concentrated in vacuo. The residue was purified by column chromatography (SiO ₂, petroleum ether/ethyl acetate=5/1 to 1/1) to give racemic compound 2 (192 g,354mmol,70.0% yield) as a pale yellow solid.

Chiral separation by preparative chromatography: racemic compound 2 (3.00 kg,5.31mol,1.00 eq.) was separated by SFC (Shimadzu mobile phase: hexane with 45% EtOH (0.1% NH ₃-H₂ O), flow rate: 140 g/min, cycle time: 9 min, total time: 4500 min, single shot volume: 16.0 mL) to give Boc-compound M-2 (1.37 kg,2.42mol,45.6% yield, 98.3% e.e.,98.2% purity) as an off-white solid.

Final deprotection to give compound M-2HCl salt: to a mixture of Boc-compound M-2 (200 g,354mmol,1 eq.) in MeOH (1.00L) at 20deg.C and N ₂ was added HCl/MeOH (4M, 250mL,2.82 eq.) in one portion. The mixture was stirred at 20-35℃for 2 hours. The reaction mixture was concentrated under reduced pressure to give a residue, which was then solvent switched three times with EtOAc. The residue was suspended in EtOAc (1.00 l,5.00 v) and stirred at 15 ℃ for 16 hours. The deprotection procedure is performed in parallel for seven (7) repetitions. All batches were combined, filtered, and the filter cake was dried under reduced pressure to an off-white solid. The solid was added to deionized water/MeOH (12/1, 10L) and stirred for 3 hours. The solution was lyophilized to give compound M-2HCl salt as an off-white solid (1050 g,2.09mol, 99.1% purity, 99.1% e.e.,84.5% yield).

¹H NMR(400MHz,DMSO-d₆):δ＝12.9(s,1H),8.67(s,3H),8.42(s,1H),8.13-8.16(d,J＝12Hz,1H),8.04(d,J＝8.0Hz,1H),7.86-7.87(d,J＝4.0Hz,1H),7.47-7.50(dd,J＝4Hz,1H),4.35(s,2H),4.23-4.28(m,1H),3.79(s,3H),0.94-0.77(m,4H).

Example 5

Coupling: cs ₂CO₃ (51.6 g,158mmol,3.30 eq.) and H ₂ O (80 mL) were mixed in a four-necked round bottom flask at 20-25℃and stirred until a clear solution was obtained. Int _AB (20.86 g,95.9% w/w,48.0mmol,1.00 eq.) Int _CD (23.58 g,97.8% w/w,57.5mmol,1.20 eq.) and toluene (240 mL) were added. The mixture was degassed under vacuum and backfilled three times with N ₂. Ad ₂ N-Pd-G3 (0.88G, 2.5 mol%) was added and the mixture was degassed under vacuum and backfilled three times with N ₂. The resulting reaction mixture was heated to an internal temperature of 57 ℃ under N ₂. After a duration of 27 hours at 57 ℃, analysis of the sample in the method showed that 2.7% IntAB remained and 87.4% of racemic Boc-compound 2 formed. The reaction was cooled to 45-50 ℃. Cysteine (4.0 g,33mmol,0.69 eq.) and 2-MeTHF (40 mL) were added to the mixture and stirring was continued for 6 hours at 45-50 ℃. The reaction mixture was filtered through a short plug of celite and the filter cake was washed with 2-MeTHF (100 mL). The aqueous phase was separated. The combined organic phases were washed with 17% aqueous NaCl (2X 100 mL). Anhydrous MgSO ₄ (20 g) and activated carbon (4.0 g) were added to the organic solution, and the resulting suspension was stirred at 50 ℃ for 4 hours. The solid was filtered off and the spent filter cake was washed with 2-MeTHF (100 mL). The combined filtrates were concentrated to a volume of about 40mL under reduced pressure at 30-60 ℃. MeOH (60 mL) was added and distillation continued until a volume of about 40mL was reached. This operation was repeated two more times to remove residual toluene and 2-MeTHF. MeOH (140 mL) was added and the mixture was stirred at 50-55 ℃ for 6 hours. The mixture was cooled to 20-25 ℃ and stirred for an additional 12 hours. The resulting slurry was filtered and the wet cake was washed with MeOH (40 mL). The wet cake obtained was dried at 60-65 ℃ for 16 hours to give racemic Boc-compound 2 (21.84 g, 80.7% yield, 99.7% LC purity) as a pale yellow solid.

Boc-deprotection and free basification of racemate: racemic Boc-compound 2 (400 g,708 mmol) and EtOAc (6.00L) were charged to a 10L four-necked round bottom flask at 23 ℃ and stirred for 15 min to dissolve the material to give a pale yellow clear solution. To the stirred mixture was added dropwise a 4M HCl in EtOAc (2.0 l,11 eq.) at 20-25 ℃ while gradually precipitating a colorless solid. The resulting suspension was stirred at 20-25℃for 21 hours, on which basis the sample in the process showed complete Boc-deprotection (0.04% Boc-compound 2 remaining). The slurry was filtered and the wet cake was washed with EtOAc (2 x 0.80 l). The filter cake was dried at 50 ℃ under reduced pressure for 2 hours to give the racemic compound 2HCl salt as a colorless solid (398 g, quantitative yield, 99.2% LC purity). The racemic compound 2HCl salt (398 g) and MeOH (4.00L) were charged into a 10L four-necked round bottom flask at 23 ℃ and stirred for 15 minutes to give a white suspension. The mixture was cooled to 5-15 ℃ under N ₂. A solution of 7M NH ₃ in MeOH (0.400L) was added dropwise to the mixture at 5-15℃under N ₂. After addition, the mixture was warmed to room temperature and stirred for an additional 13 hours. The mixture was cooled to 10-15 ℃ under N ₂ and stirred for 1 hour to obtain a colorless slurry. The solid was collected by filtration and dried at 50 ℃ for 18 hours to give the racemic compound 2 free base as a colourless solid (312.2 g,96.0% w/w,99.7% LC purity, 94.9% yield).

Separation of atropisomers: the racemic compound 2 free base was then treated as described above in examples 1A and 1B to obtain the desired compound M-2.

Example 6

1,1' -Di-2-naphthol (5.71 g,19.9mmol,1 eq.) was added to an Erlenmeyer flask equipped with a magnetic stirring bar. 80mL of toluene was added to the flask. The flask was then heated to 80 ℃ on a hot plate while stirring. (1R, 2R) -diaminocyclohexane (2.28 g,19.9mmol,1 eq.) was added to hot BINOL and the slurry quickly turned into homogeneous phase. After becoming homogeneous crystals began to form, the heating was turned off and the mixture was cooled to room temperature and aged for 1 hour. Samples of the supernatant were collected for HPLC analysis. The samples contained XYZ of R-BINOL and XYZ of S-BINOL. The 20 μm stainless steel HPLC filter from IDEX was immersed in toluene. It is connected to Eldex Optos Model metering pumps via 1/8"o.d. pfa tubing (1/16" i.d.). The pump was connected to a stainless steel plug flow reactor (3.5 mL,1/8"O.D,0.09" I.D.) through a PFA tubing (1/8 "O.D.), 1/16" I.D.). Swagelok 1/8 "compression fitting was used to securely connect pipes. The outlet of the Plug Flow Reactor (PFR) was connected to a IDEX 250psi spring-loaded back pressure regulator. The stream flows from bpr and returns to the Erlenmeyer crystallization flask. The plug flow reactor was immersed in mineral oil heated to 200 ℃ and the recycle loop was pre-filled with pure toluene before pumping the BINOL solution through the stainless steel filter and PFR to facilitate the start-up of the recycle procedure. The pump driving the circulation loop was operated at a rate of 3 ml/min and the circulation was run continuously for 30 hours. After this time, the solids in the flask were filtered. The solid was washed with 5mL of toluene and placed on a filter until dry to obtain 7.88g of a white solid. The complex was a 1:1:1 mixture of BINOL, diamine and toluene (MW 492 g/mol). Samples were submitted for 1H qNMR analysis to obtain the measured weight percent (fig. 4). The spectra are consistent with those reported in the literature. It is 81.0% measured wt. percent 99.6% of the BINOL/diaminocyclohexane complex, which corresponds to 99.6 measured wt.% of a 1:1:1 complex of BINOL, diamine and toluene. The isolation yield adjusted by the measurement was 80%. Samples were subjected to chiral HPLC analysis. The samples showed 99.65% R-BINOL and 0.35% S-BINOL (99.3% ee) (FIGS. 5-9).

HPLC conditions of BINOL. Spectra of R and S isomers of BINOL

Example 7: batch splitting

Rac-Compound 2 (1.0 eq) and Boc-D-Phe (1.1 eq) were dissolved in EtOH:water (90:10V/V, 12V) at room temperature. The resulting supersaturated mixture was inoculated with 0.5% w/w of the compound M-2 Boc-D-phenylalanine salt and equilibrated at about 22℃until preferential crystallization of the compound M-2 Boc-D-phenylalanine salt was completed, while the supernatant became enriched with the undesired enantiomer salt (compound P-2 Boc-D-phenylalanine salt). The crystalline solid was isolated by filtration and subjected to additional reslurry in aqueous EtOH (85:15V/V, 10V) to effect additional chiral upgrades (objective: obtaining. The mother liquor consisting of a mixture of compound P-2 Boc-D-phenylalanine salt and compound M-2 Boc-D-phenylalanine salt in aqueous EtOH was thermally racemized at 70-80 ℃ (objective: <20% enantiomeric excess [ e.e. ] obtained by chiral HPLC) for 24-48 hours. Another batch of compound M-2 Boc-D-phenylalanine salt was obtained by repeating the aging and reslurrying as described above (objective: obtaining an enantiomeric excess of 95.5% by chiral HPLC [ e.e. ]). The resulting crystalline solid was dried at about 45℃to give compound M-2 Boc-D-phenylalanine as an off-white solid in a total yield of 60% (first: 37% yield; second: 23% yield) (FIG. 10).

HPLC conditions for compound 2.

Example 8: continuous splitting

Racemic compound 2 (92.4 wt%,10.82g,21.5 mmol) was suspended in an ethanol and water mixture (EtOH: water: 98:2v/v,100 mL) in a 100mL EasyMax reactor. Solid Boc-D-phenylalanine (6.25 g,23.6mmol,1.1 eq.) was added and the resulting thick slurry was stirred at 600rpm using an overhead stirrer at room temperature. Within 10 minutes, almost all solids entered the solution to give a thin pale yellow suspension. The supersaturated solution of the compound M-2 Boc-D-phenylalanine salt thus obtained was inoculated with the crystalline compound M-2 Boc-D-phenylalanine salt (78 mg,0.0050 eq.) and equilibrated at room temperature by efficient stirring. After about 16 hours, a thick slurry of crystals was obtained. Analysis of the supernatant by chiral LC showed 91.5% compound P-2 and 8.5% compound M-2 (83% e.e.), wherein compound P-2 Boc-D-phenylalanine salt was 39.7mg/mL (equilibrium solubility about 40 mg/mL) and compound M-2 Boc-D-phenylalanine salt was 3.7mg/mL (equilibrium solubility about 4 mg/mL). After the mixture was determined to be near equilibrium, continuous resolution was initiated. A 20 μm stainless steel HPLC filter from IDEX was immersed in a crystallization vessel (100 mL EasyMax reactor) containing a thick slurry of the compound M-2 Boc-D-phenylalanine salt in an ethanol-water mixture. It was connected to SYRRIS ASIA syringe pumps via 1/16"o.d.pfa tubing (0.03" i.d.). The pump was connected to a plug flow reactor made of PFA tubing (1.5 mL,1/16"O.D,0.03" I.D.). The outlet of the Plug Flow Reactor (PFR) was connected to a IDEX 250psi spring-loaded back pressure regulator. The stream flows from bpr and returns to the crystallization vessel. The plug flow reactor was immersed in mineral oil heated to 160 ℃. The pump driving the circulation loop was operated at a rate of 0.75 ml/min and the circulation was run continuously for 14.5 hours. Intermittent HPLC sampling was performed. After 14.5 hours, the production phase of the continuous resolution was completed as indicated by nearly identical supernatant concentrations of compound P-2 Boc-D-phenylalanine salt and compound M-2 Boc-D-phenylalanine salt (5.4 mg/mL and 4.3mg/mL, respectively). The slurry from the crystallizer was filtered. The filter cake was thoroughly powdered and air dried to give technical compound M-2 Boc-D-phenylalanine salt (14.43 g,94.2wt%,90% d.r.,98.0% LC) as an off-white powder in 87% yield. With temperature cycling (20-40 ℃), an additional reslurry was performed in aqueous EtOH (EtOH: water: 95:5V/V, 10V) for 6 hours, increasing chiral purity (96.6 d.r) at the expense of 5% product loss from the solution.

Example 9: continuous resolution (separate crystallization Module and Collection Module)

An arrangement for continuous resolution with separate crystallization and collection modules is depicted in fig. 12.

Boc-d-phenylalanine (1.37 g,5.16mmol,1.20 eq.) was dissolved in EtOH: 98:2v/v (20 mL,10 vol). Racemic compound 2 (90.0 wt%,2.22g,4.30mmol assay) was added in portions to a well-stirred solution of Boc-d-phenylalanine. The following aliquots of racemic compound 2 were added, taking into account the dissolution time between charges: 222mg (part 1, t=0), 245mg (part 2, t=14 minutes), 267mg (part 2, t=36 minutes). The resulting turbid solution was inoculated with crystals of compound M-2 Boc-d-phenylalanine salt (6 mg, t=42 min). Crystal growth was observed over time, producing a fluid slurry. The remaining racemic compound 2 was added in portions: 290mg (t=82 min), 233mg (t=101 min), 271mg (t=179 min), 694mg (t=131 min). With EtOH: the resulting thick mixture was diluted 98:2v/v (20 ml,10 vol) (t=144 minutes) to obtain a fluid slurry. The collection module (tank) is filled with slurry. The supernatant was pumped from the collection module through a filter (20 μm, sintered metal) into an epimerization module (racemizer) (150-160 ℃) allowing a residence time of 2 minutes (0.75 mL/min flow rate, 1.5mL racemizer volume). The racemized output is fed to a well-stirred crystallization module (crystallizer) where the compound M-2 Boc-d-phenylalanine salt is rapidly crystallized to give a suspension (slurry). The slurry was peristaltic transferred from the crystallizer (pump not shown) while maintaining its volume at about 10mL. The average residence time in the crystallizer was about 13 minutes (10 ml,0.75 ml/min). The slurry is transferred back to the collection module, completing the cycle. The pumping process was continued for 5 hours, on the basis of which the supernatant concentration of the undesired P-enantiomer actually matched the concentration of the desired M-enantiomer, indicating that the process was equilibrated. The contents of the system were filtered and the resulting filter cake was air dried to give compound M-2 Boc-d-phenylalanine salt (2.25 g) as an off-white powder.

Placing the crystallization module between the racemate and the collection module significantly shortens the time to equilibrium (fig. 11).

In this example, as shown in fig. 12, the apparatus comprises a relatively small crystallization module or vessel (crystallizer) located directly downstream of the epimerization module (racemate) and upstream of the collection module (collection tank). The racemic stream from the epimerization module or the racemizer (i.e., the superheating loop) is fed directly into the collection module, allowing the operation of the resolution process to be performed under the most desirable conditions within the crystallization module. See fig. 13.

***

While the application has been described in connection with specific embodiments thereof, it will be understood that the application is capable of further modifications and this application is intended to cover any variations, uses, or adaptations of the application following, in general, the principles of the application and including such departures from the present disclosure as come within known or customary practice within the art to which the application pertains and as may be applied to the essential features hereinbefore set forth and as follows in the scope of the appended claims.

Claims

1. Method for separating a mixture of (2M) -2- (4- (4- (aminomethyl) -1-oxo-1, 2-dihydro-phthalazin-6-yl) -1-methyl-1H-pyrazol-5-yl) -4-chloro-6-cyclopropyloxy-3-fluorobenzonitrile (compound M-2) enantiomer and (2P) -2- (4- (4- (aminomethyl) -1-oxo-1, 2-dihydro-phthalazin-6-yl) -1-methyl-1H-pyrazol-5-yl) -4-chloro-6-cyclopropyloxy-3-fluorobenzonitrile (compound P-2) enantiomer

The method comprises the following steps:

(a) Contacting the mixture with N-Boc-D-phenylalanine to form a mixture of a compound M-2N-Boc-D-phenylalanine salt and a compound P-2N-Boc-D-phenylalanine salt;

(b) Filtering the mixture to obtain a solid phase enriched in the salt of the compound M-2N-Boc-D-phenylalanine; and

(C) The solid phase is reacted with excess NH ₃ or other base to obtain a solid enriched in the M-enantiomer free base of 2- (4- (4- (aminomethyl) -1-oxo-1, 2-dihydro-phthalazin-6-yl) -1-methyl-1H-pyrazol-5-yl) -4-chloro-6-cyclopropyloxy-3-fluorobenzonitrile.

2. The process of claim 1, wherein the contacting in step (a) occurs in MeOH or an aqueous MeOH solution.

3. The method of claim 1, wherein the contacting in step (a) occurs in EtOH or an aqueous EtOH solution.

4. The method of claim 3, wherein the aqueous EtOH solution is about 90% EtOH and about 10% water (v/v).

5. The process according to claim 1, wherein the contacting in step (a) occurs in THF or an aqueous THF solution.

6. The method according to any one of claims 1 to 5, wherein the solid phase obtained in step (b) is washed one or more times with an additional solvent to remove compound P-2N-Boc-D-phenylalanine salt.

7. The process according to any one of claims 1 to 6, wherein the reaction of step (c) occurs in isopropanol solution or in isopropanol and aqueous solution.

8. The method according to any one of claims 1 to 6, wherein the reaction of step (c) is seeded with a free base compound M-2.

9. The process according to any one of claims 1 to 8, wherein the enriched solid obtained in step (c) is separated from the reaction mixture by a further filtration step. .

10. The method according to any one of claims 1 to 9, wherein the enriched solid obtained in step (c) is further purified by one or more slurry or washing steps designed to remove residual N-Boc-D-phenylalanine.

11. The process according to any one of claims 1 to 10, wherein the filtrate enriched in compound P-2N-Boc-D-phenylalanine salt from step (b) is heated to obtain a racemic or almost racemic mixture of compound P-2 and compound M-2.

12. The method of claim 11, wherein the mixture is separated to obtain the pure or enriched compound M-2N-Boc-D-phenylalanine salt.

13. A method of separating a mixture of the M-2 enantiomer of compound and the P-2 enantiomer of compound, the method comprising the steps of:

(a) Contacting the mixture with N-Boc-L-phenylalanine to form a mixture of a compound M-2N-Boc-L-phenylalanine salt and a compound P-2N-Boc-L-phenylalanine salt;

(b) Filtering the solid phase to obtain a liquid phase enriched in said compound M-2N-Boc-L-phenylalanine salt; and

(C) The compound M-2N-Boc-L-phenylalanine salt is reacted with a base to obtain a solid free base compound M-2.

14. The process of claim 13, wherein the contacting in step (a) occurs in MeOH or an aqueous MeOH solution.

15. The method of claim 13, wherein the contacting in step (a) occurs in EtOH or an aqueous EtOH solution.

16. The method of claim 15, wherein the aqueous EtOH solution is about 90% EtOH and about 10% water (v/v).

17. The process according to claim 13, wherein the contacting in step (a) occurs in THF or an aqueous THF solution.

18. The process according to any one of claims 13 to 17, wherein the aqueous phase obtained in step (b) is concentrated to dryness to obtain the solid compound M-2 enriched in the N-Boc-L-phenylalanine salt.

19. The process according to any one of claims 1 to 18, wherein step (c) occurs in a suspension of water and dichloromethane.

20. The process according to any one of claims 1 to 18, wherein step (c) occurs in addition to the suspension of water and dichloromethane.

21. The process according to any one of claims 1 to 18, wherein the enriched compound M-2 free base obtained in step (c) is slurried and filtered to remove racemic free base compound 2, so as to further enrich the proportion of free base compound M-2 in the solution.

22. A method of obtaining a substantially pure or enriched compound M-2, the method comprising the steps of:

(a) Obtaining a mixture of Boc-protected compound M-2 and Boc-protected compound P-2;

(b) Chromatographic separation of said Boc-protected compound M-2 from said Boc-protected compound P-2; and

(C) Deprotection of the Boc protected compound M-2.

23. A method for producing a sample containing a diastereomeric excess of compound M-2, the method comprising heating a mixture of compound P-2N-Boc-D-phenylalanine salt and compound M-2N-Boc-D-phenylalanine salt having a first ratio to obtain a mixture of compound P-2N-Boc-D-phenylalanine salt and compound M-2N-Boc-D-phenylalanine salt having a second ratio.

24. The method of claim 23, wherein the ratio is about the ratio of the racemic mixture of the compound M-2N-Boc-D-phenylalanine salt to the compound P-2N-Boc-D-phenylalanine salt.

25. The method of claim 23, wherein the mixture is separated to obtain the pure or enriched compound M-2N-Boc-D-phenylalanine salt.

26. A compound which is the N-Boc-D-phenylalanine salt of (2M) -2- (4- (4- (aminomethyl) -1-oxo-1, 2-dihydro-phthalazin-6-yl) -1-methyl-1H-pyrazol-5-yl) -3-fluoro-3, 4-dihydro-naphthalene-1-carbonitrile.

27. A compound which is the N-Boc-D-phenylalanine salt of (2P) -2- (4- (4- (aminomethyl) -1-oxo-1, 2-dihydro-phthalazin-6-yl) -1-methyl-1H-pyrazol-5-yl) -3-fluoro-3, 4-dihydro-naphthalene-1-carbonitrile;

28. A compound which is the N-Boc-L-phenylalanine salt of (2M) -2- (4- (4- (aminomethyl) -1-oxo-1, 2-dihydro-phthalazin-6-yl) -1-methyl-1H-pyrazol-5-yl) -3-fluoro-3, 4-dihydro-naphthalene-1-carbonitrile;

29. A compound which is the N-Boc-L-phenylalanine salt of (2P) -2- (4- (4- (aminomethyl) -1-oxo-1, 2-dihydro-phthalazin-6-yl) -1-methyl-1H-pyrazol-5-yl) -3-fluoro-3, 4-dihydro-naphthalene-1-carbonitrile;

30. A compound which is the N-Boc-D-phenylalanine salt of (2M) -2- (4- (4- (aminomethyl) -1-oxo-1, 2-dihydro-phthalazin-6-yl) -1-methyl-1H-pyrazol-5-yl) -4-chloro-6-cyclopropyloxy-3-fluorobenzonitrile;

31. A compound which is the N-Boc-D-phenylalanine salt of (2P) -2- (4- (4- (aminomethyl) -1-oxo-1, 2-dihydro-phthalazin-6-yl) -1-methyl-1H-pyrazol-5-yl) -4-chloro-6-cyclopropyloxy-3-fluorobenzonitrile

32. A compound which is the N-Boc-L-phenylalanine salt of (2M) -2- (4- (4- (aminomethyl) -1-oxo-1, 2-dihydro-phthalazin-6-yl) -1-methyl-1H-pyrazol-5-yl) -4-chloro-6-cyclopropyloxy-3-fluorobenzonitrile; and

33. A compound which is the N-Boc-L-phenylalanine salt of (2P) -2- (4- (4- (aminomethyl) -1-oxo-1, 2-dihydro-phthalazin-6-yl) -1-methyl-1H-pyrazol-5-yl) -4-chloro-6-cyclopropyloxy-3-fluorobenzonitrile.

34. A crystalline form of the N-Boc-D-phenylalanine salt of (2M) -2- (4- (4- (aminomethyl) -1-oxo-1, 2-dihydro-phthalazin-6-yl) -1-methyl-1H-pyrazol-5-yl) -4-chloro-6-cyclopropyloxy-3-fluorobenzonitrile.

35. A crystalline form a of (2M) -2- (4- (4- (aminomethyl) -1-oxo-1, 2-dihydro-phthalazin-6-yl) -1-methyl-1H-pyrazol-5-yl) -4-chloro-6-cyclopropyloxy-3-fluorobenzonitrile.

36. A crystalline form a of (2M) -2- (4- (4- (aminomethyl) -1-oxo-1, 2-dihydro-phthalazin-6-yl) -1-methyl-1H-pyrazol-5-yl) -4-chloro-6-cyclopropyloxy-3-fluorobenzonitrile hydrochloride.

37. A crystalline form B of (2M) -2- (4- (4- (aminomethyl) -1-oxo-1, 2-dihydro-phthalazin-6-yl) -1-methyl-1H-pyrazol-5-yl) -4-chloro-6-cyclopropyloxy-3-fluorobenzonitrile hydrochloride.

38. A method of separating a mixture of atropisomers, the method comprising:

(c) Withdrawing a portion of the liquid phase;

(F) Separating the crystals of the first atropisomer.

39. The method of separating a mixture of atropisomers according to claim 38, wherein the atropisomers are compounds having the formula

Wherein the method comprises the steps of

Ring A is

Z is N, CH or CR ¹;

n is 0, 1, 2, 3 or 4;

x is 0, 1 or 2;

m is 0, 1, 2, 3 or 4;

40. The process for separating a mixture of atropisomers according to claim 38 or claim 39, wherein said withdrawing, said subjecting, and said returning are continued until the amount of the second atropisomer in the liquid phase is below a predetermined level.

41. The method of separating a mixture of atropisomers according to any one of claims 38 to 40, wherein

42. The method of separating a mixture of atropisomers according to any one of claims 38 to 41, wherein the first atropisomer is (2M) -2- (4- (4- (aminomethyl) -1-oxo-1, 2-dihydro-phthalazin-6-yl) -1-methyl-1H-pyrazol-5-yl) -4-chloro-6-cyclopropyloxy-3-fluorobenzonitrile (compound M-2), and the second atropisomer is (2P) -2- (4- (4- (aminomethyl) -1-oxo-1, 2-dihydro-phthalazin-6-yl) -1-methyl-1H-pyrazol-5-yl) -4-chloro-6-cyclopropyloxy-3-fluorobenzonitrile (compound P-2).

43. The method of separating a mixture of atropisomers according to any one of claims 38 to 42, wherein the mixture of the solvent, the first atropisomer and the second atropisomer further comprises a resolving agent that is N-Boc-D-phenylalanine.

44. The process of separating a mixture of atropisomers according to any one of claims 38 to 43, wherein the solvent is MeOH or an aqueous MeOH solution.

45. The method for separating a mixture of atropisomers according to any one of claims 38 to 43, wherein the solvent is EtOH or aqueous EtOH,

46. The method of separating a mixture of atropisomers according to any one of claims 38 to 43, wherein the solvent is EtOH/water from about 90:10 (v/v) to about 99:1 (v/v).

47. The method of separating a mixture of atropisomers according to any one of claims 38 to 46, wherein the adjustment in (b) is to a temperature of about 20-25 ℃.

48. The method of separating a mixture of atropisomers according to any one of claims 38 to 47, wherein the subjecting in (d) comprises heating at a temperature of about 80-200 ℃.

49. The method of claim 1, wherein

The contacting produces a slurry comprising

Enriching the liquid phase of the compound P-2N-Boc-D-phenylalanine salt; and

The method further comprises

Separating a portion of the liquid phase from the slurry, and

50. The method of claim 49, wherein the ratio after said heating is about the ratio of the racemic mixture of said compound M-2N-Boc-D-phenylalanine salt and said compound P-2N-Boc-D-phenylalanine salt.

51. The method of claim 49 or claim 50, further comprising cooling the heated mixture to produce a cooled mixture comprising a solid phase enriched in the compound M-2N-Boc-D-phenylalanine salt and a liquid phase enriched in the compound M-2N-Boc-D-phenylalanine salt.

52. The method of claim 51, wherein the cooling of the heated mixture comprises combining the heated mixture with the slurry.

53. A system for separating atropisomers, the system comprising a crystallization module, an epimerization module, and optionally a collection module.

54. The system of claim 53, wherein the crystallization module is fluidly connected to the epimerization module by a take-off channel and a return channel.

55. The system of claim 53 or claim 54, wherein material is continuously or semi-continuously withdrawn from the crystallization module and fed directly or indirectly into the epimerization module, and material is at least semi-continuously returned from the epimerization module to the crystallization module.

56. A method for separating atropisomers, the method comprising

Epimerization of the more soluble atropisomer in an epimerization module;

57. The process of claim 56, wherein said selectively crystallizing comprises introducing a solvent and a mixture of a first atropisomer and a second atropisomer into said crystallization module, wherein said first atropisomer and said second atropisomer have different solubilities in said solvent, and optionally adjusting the temperature to crystallize said less soluble atropisomer.

58. The method of claim 56 or 57, wherein said epimerization comprises subjecting said more soluble atropisomer to conditions sufficient to produce an increased amount of said less soluble atropisomer.

59. The system of claim 54, wherein the take-off channel comprises the collection module fluidly and directly connected to the epimerization module and the crystallization module, and the return channel is fluidly and indirectly connected to the crystallization module and the epimerization module.