Preparation method of lysine specific demethylase 1 (LSD1) inhibitor key intermediate

Abstract

The invention relates to the technical field of drug synthesis, and discloses a preparation method of a lysine-specific demethylase 1 (LSD1) inhibitor key intermediate, and the preparation method of the intermediate comprises the following steps: step 1, esterification reaction: reacting a compound A with a symmetric carbonylation reagent X to generate an asymmetric carbonate compound B; step 2, amine-ester exchange reaction: exchanging ester groups in the compound B with amine groups in the compound C to generate an amide compound D; step 3, cyclization reaction: converting carbonyl in the compound D into epoxy substituent in the compound E; and 4, fluorination reaction: reacting the compound E with a fluorination reagent, and carrying out ring opening to generate a fluorine substituted compound F. The preparation method comprises the following steps: oxidizing a key intermediate of the LSD1 inhibitor, connecting the key intermediate with an amine fragment, and performing functional group modification to obtain the fluorine-substituted cyclopropylamine compound with LSD1 inhibitory activity, thereby achieving the beneficial effect that the fluorine-substituted cyclopropylamine compound with LSD1 inhibitory activity can be conveniently and quickly synthesized from the intermediate.

Description

Technical Field

[0001] The present invention relates to the technical field of drug synthesis, and in particular to a method for preparing a key intermediate of a lysine-specific demethylase 1 (LSD1) inhibitor. Background Art

[0002] LSD1 (also known as BHC110, p110b, and NPAO) was identified by Shi's group in 2004, and its structure is highly conserved from yeast to humans. In cells, LSD1's demethylation ability is highly gene-, substrate-, and environmental-specific, producing different (or even opposite) effects on gene expression at different loci. Studies have found that LSD1 plays an important role in promoting normal cell differentiation, and LSD1 has also been found to be abnormally recruited to produce inappropriate repression of abnormal gene targets downstream of leukemic gene damage (such as MLL-AF9). In this case, LSD1 maintains the activity of leukemic stem cells (LSCs) conferred by the initial injury, and the cellular effects downstream of LSD1 are also significantly different from the normal cell state. In normal hematopoiesis, no changes in gene expression were found at the level of the most primitive hematopoietic stem cells (HSCs), which is consistent with the observation that hematopoiesis is induced by the exact opposite LSD1 depletion. Therefore, if LSD1 can produce controllable and reversible toxicity to normal hematopoietic cells, it can be used as a potential drug target for the treatment of leukemia. The development and synthesis of novel small molecule LSD1 inhibitors has important research significance for the treatment of malignant tumors and leukemia.

[0003] Prior art CN 107200706 A reports a class of fluorine-substituted cyclopropylamine compounds and their preparation methods, pharmaceutical compositions and uses:

[0004] It can be seen from the above preparation scheme that patent CN 107200706 A only protects the key step of reductive amination to prepare the target compound and the key starting material cyclopropylamine compounds. At the same time, the intermediates cannot be used to conveniently and quickly synthesize fluorine-substituted cyclopropylamine compounds with LSD1 inhibitory activity. Summary of the invention

[0006] In view of the deficiencies of the prior art, the present invention provides a method for preparing a class of key intermediates of lysine-specific demethylase 1 (LSD1) inhibitors, which has the advantages of convenient and quick synthesis of fluorine-substituted cyclopropylamine compounds with LSD1 inhibitory activity, and solves the problems of the above-mentioned technologies. Technical Solution

[0007] To achieve the above object, the present invention provides the following technical solution: a method for preparing a key intermediate of a lysine-specific demethylase 1 (LSD1) inhibitor, wherein the intermediate has the structure:

[0008] in: R1 is selected from the group consisting of ethyl, benzyl, phenyl, cyclohexylmethyl, 4-pyridylmethyl, phenylethyl, 1H-indol-5-ylmethyl, 2-thienylmethyl, 2-furylmethyl, 4-fluorophenylmethyl, 4-chlorophenylmethyl, 4-bromophenylmethyl, 4-methoxyphenyl, 4-trifluoromethylphenylmethyl, 3,5-dimethoxyphenylmethyl, 4-formylphenylmethyl, cyclopentylmethyl, cyclobutylmethyl, 4-piperidinylmethyl, 3-chlorophenylmethyl, 2-chlorophenylmethyl, or 4-tert-butylphenylmethyl; R2 is selected from: methyl; Wherein: n is 0-2, when n is 0, it means there is no methyl substitution on the ring; The intermediate preparation route is:

[0009] The intermediate preparation method is: Step 1, esterification reaction: Compound A reacts with a symmetrical carbonylation reagent X to generate an asymmetrical carbonate compound B; Step 2: Amine ester exchange reaction: the ester group in compound B is exchanged with the amine group in compound C to generate amide compound D; Step 3: Cyclization reaction, the carbonyl group in compound D is converted into the epoxy substituent in compound E; Step 4, fluorination reaction: Compound E is reacted with a fluorination agent to open the ring to generate a fluorine-substituted compound F; Wherein: X is selected from: phosgene, triphosgene, dimethyl carbonate, diethyl carbonate, N,N'-succinimidyl carbonate, di(p-nitrobenzene) carbonate; R1 is selected from the group consisting of ethyl, benzyl, phenyl, cyclohexylmethyl, 4-pyridylmethyl, phenylethyl, 1H-indol-5-ylmethyl, 2-thienylmethyl, 2-furylmethyl, 4-fluorophenylmethyl, 4-chlorophenylmethyl, 4-bromophenylmethyl, 4-methoxyphenyl, 4-trifluoromethylphenylmethyl, 3,5-dimethoxyphenylmethyl, 4-formylphenylmethyl, cyclopentylmethyl, cyclobutylmethyl, 4-piperidinylmethyl, 3-chlorophenylmethyl, 2-chlorophenylmethyl, or 4-tert-butylphenylmethyl; R2 is selected from: methyl; n is 0-2, and when n is 0, it means that there is no methyl substitution on the ring.

[0010] Preferably, the symmetrical carbonylation reagent in step 1 is phosgene, triphosgene, dimethyl carbonate, diethyl carbonate, N,N'-succinimidyl carbonate, di(p-nitrobenzene) carbonate.

[0011] Preferably, in step 1, the base is triethylamine, pyridine, 4-dimethylaminopyridine, N,N-diisopropylethylamine, potassium carbonate, sodium carbonate, sodium bicarbonate, sodium acetate; and the solvent is tetrahydrofuran, 2-methyltetrahydrofuran, acetonitrile, dichloromethane, toluene, dimethylformamide, methyl tert-butyl ether or dioxane.

[0012] Preferably, the reaction temperature in step 1 is 0-55°C.

[0013] Preferably, the base in the second amine ester exchange reaction is triethylamine, pyridine, 4-dimethylaminopyridine, N,N-diisopropylethylamine, potassium carbonate, sodium carbonate, sodium bicarbonate, sodium acetate; and the solvent in the second step is tetrahydrofuran, 2-methyltetrahydrofuran, acetonitrile, dichloromethane, toluene, dimethylformamide, methyl tert-butyl ether or dioxane.

[0014] Preferably, the reaction temperature in step 2 is 0-55°C.

[0015] Preferably, the methylating agent in step 3 is trimethylsulfonium iodide, trimethylsulfonium bromide, dibromomethane, chloroiodomethane, chlorobromomethane, phenyldimethylmethanesulfonate selenium, trimethylsulfoxide iodide, trimethylsulfoxide bromide, trimethylsilane or dimethyl-N-(p-toluenesulfonyl)sulfoxime.

[0016] Preferably, the base in step three is potassium hydroxide, butyl lithium, sodium hydride, sodium tert-butoxide, potassium tert-butoxide; and the solvent is dimethyl sulfoxide, tetrahydrofuran, acetonitrile or ethylene glycol dimethyl ether.

[0017] Preferably, in the fluorination reaction in step 4, the fluorination reagent is pyridine hydrofluoric acid, tetrabutylammonium fluoride, boron trifluoride etherate, or potassium difluoride.

[0018] Preferably, the solvent in step 4 is tetrahydrofuran, toluene, dimethylformamide, dimethyl sulfoxide or dichloromethane.

[0019] Compared with the prior art, the present invention provides a method for preparing a key intermediate of a lysine-specific demethylase 1 (LSD1) inhibitor, which has the following beneficial effects: 1. The present invention obtains fluorine-substituted cyclopropylamine compounds with LSD1 inhibitory activity by oxidizing the key intermediate of this type of LSD1 inhibitor and then connecting it with an amine fragment and performing functional group modification, thereby achieving the beneficial effect of conveniently and quickly synthesizing fluorine-substituted cyclopropylamine compounds with LSD1 inhibitory activity from the intermediate. DETAILED DESCRIPTION

[0020] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0021] Embodiment 1 Preparation of 4-fluoro-4-(hydroxymethyl)piperidine-1-carboxylic acid phenylmethyl ester (F1) Synthesis route:

[0022] Preparation of B1: Compound A1 (500 g, 4.62 mol, 1.0 eq) was dissolved in anhydrous acetonitrile (3 L), triethylamine (1402.5 g, 13.86 mol, 3 eq) and N,N'-succinimidyl carbonate (1775.3 g, 6.93 mol, 1.5 eq) were slowly added, and the reaction solution was stirred at 25°C overnight. LCMS showed that compound A1 was completely reacted and compound B1 was generated. The solvent of the reaction solution was dried by vortexing, and a saturated sodium bicarbonate aqueous solution (2 L) was slowly added, followed by extraction with ethyl acetate (2 L x 2). The organic phases were combined, washed with water (500 mL x 2), washed with saturated brine (500 mL x 2), dried over anhydrous sodium sulfate, filtered and dried by vortexing. The obtained crude product was slurried with petroleum ether and methyl tert-butyl ether, filtered and the solid was collected. After drying, 1095 g of a pale yellow solid crude product was obtained, which was directly used for the next step without purification. LC-MS (ESI): m / z [M+H] + = 250.

[0023] Preparation of D1: Compound C1 (434 g, 4.01 mol, 1.0 eq) was dissolved in a mixture of water (6.65 L) and 1,4-dioxane (1.1 L), sodium bicarbonate (674 g, 8.02 mol, 2 eq) was added, and the reaction mixture was heated at 25 o C for 15 min, then a 1,4-dioxane solution (6.68 L) of compound B1 (1000 g, 4.01 mol, 1 eq) was added, and the reaction mixture was stirred at 25 oC for 12 hours, LCMS showed that compound B1 was completely reacted and compound D1 was generated. The reaction solution was spin-dried, saturated sodium bicarbonate aqueous solution (2 L) was added, the mixed solution was extracted with ethyl acetate (3 L x 2), the organic phases were combined and washed with water (500 mL x 2), washed with saturated brine (500 mL x 2), dried over anhydrous sodium sulfate, filtered and spin-dried, and slurried with petroleum ether and methyl tert-butyl ether to obtain 870 g of a yellow solid crude product, which was directly used for the next step without purification.

[0024] Preparation of E1: Dissolve trimethylsulfoxide iodide (883 g, 4.01 mol, 1.1 eq) in anhydrous dimethylsulfoxide (3.06 L) solution, add 60% sodium hydride (160.4 g, 4.01 mol, 1.1 eq), 25 o C for 0.5 h, then compound D1 (850 g, 3.64 mol, 1 eq) was added and the mixture was stirred at 60 o The reaction was continued for 4 hours under the condition of C. LCMS showed that the reaction of compound D1 was complete. o C, slowly pour the reaction solution into ice water, extract twice with ethyl acetate (2L), combine the organic phases, wash with saturated brine, dry over anhydrous sodium sulfate, filter and spin dry, and purify by column to obtain 720 g of yellow oil. The total yield of the first three steps is 63%.

[0025] Preparation of F1: Dissolve 70% pyridinium hydrofluoride (298 mL) in anhydrous dichloromethane (756 mL) and lower the reaction temperature to -25 o C, and then the temperature is controlled at -25±5 o C, dropwise add compound E1 (700 g, 2.83 mol, 1 eq) in dichloromethane (756 mL) over 60 minutes. After the addition, the reaction solution is heated to 20 ± 5 o C overnight. LCMS showed that compound E1 was completely reacted, and the main product was compound F1. The reaction solution was slowly poured into a mixture of ice water and dichloromethane, and then the mixture was extracted with dichloromethane (1 L x 2). The organic phases were combined, washed with water (500 mL x 2), washed with saturated brine (500 mL x 2), dried over anhydrous sodium sulfate, filtered and dried by spin drying, and purified by column to obtain a yellow viscous oil, followed by the addition of 1 L of methyl tert-butyl ether and 20 o The mixture was stirred at room temperature for 12 h under C conditions. A large amount of solid precipitated, which was filtered and dried to obtain 310 g of a white solid. The yield was 41%.

[0026] Embodiment 2 Preparation of 3-chlorophenylmethyl 4-fluoro-4-(hydroxymethyl)piperidine-1-carboxylate (F2)

[0027] According to the method for synthesizing F1, the benzyl group in the starting material is replaced with 3-chlorobenzyl to obtain compound F2. The total yield is 28%. Example

[0028] Preparation of 4-fluoro-4-(hydroxymethyl)piperidine-1-carboxylic acid-furan-2-ylmethyl ester (F3)

[0029] According to the method for synthesizing F1, the phenyl group in the starting material is replaced with furan-2-yl to obtain compound F3. The total yield is 21%.

[0030] Implementation Case 4 Preparation of cyclohexylmethyl 4-fluoro-4-(hydroxymethyl)piperidine-1-carboxylate (F4)

[0031] According to the method for synthesizing F1, the phenyl group in the starting material is replaced by a cyclohexyl group to obtain compound F4. The total yield is 17%.

[0032] Implementation Case 5 Preparation of 4-fluoro-4-(hydroxymethyl)piperidine-1-carboxylic acid pyridin-4-ylmethyl ester (F5)

[0033] According to the method for synthesizing F1, the phenyl group in the starting material is replaced with pyridin-4-yl to obtain compound F5. The total yield is 16%.

[0034] Implementation Case 6 Preparation of 4-fluoro-4-(hydroxymethyl)piperidine-1-carboxylic acid-thiophen-2-ylmethyl ester (F6)

[0035] According to the method for synthesizing F1, the phenyl group in the starting material is replaced with thiophene-2-yl to obtain compound F6. The total yield is 18%.

[0036] Implementation Case 7 Preparation of 4-fluoro-4-(hydroxymethyl)piperidine-1-carboxylic acid-4-fluorophenyl methyl ester (F7)

[0037] According to the method for synthesizing F1, the phenyl group in the starting material is replaced with 4-fluorophenyl to obtain compound F7. The total yield is 19%.

[0038] Implementation Case 8 Preparation of 4-methoxyphenylmethyl 4-fluoro-4-(hydroxymethyl)piperidine-1-carboxylate (F8)

[0039] According to the method for synthesizing F1, the phenyl group in the starting material is replaced with 4-methoxyphenyl to obtain compound F8. The total yield is 24%.

[0040] Implementation Case 9 Preparation of 4-fluoro-4-(hydroxymethyl)piperidine-1-carboxylic acid-(1-(tert-butyloxycarbonyl)piperidin-4-yl)methyl ester (F9)

[0041] According to the method for synthesizing F1, the phenyl group in the starting material is replaced with 1-(tert-butyloxycarbonyl)piperidin-4-yl to obtain compound F9. The total yield is 21%.

[0042] Implementation Case 10 Preparation of 4-fluoro-4-(hydroxymethyl)piperidine-1-carboxylic acid phenyl ester (F10)

[0043] According to the method for synthesizing F1, the benzyl group in the starting material is replaced by a phenyl group to obtain compound F10. The total yield is 12%.

[0044] Implementation Case 11 Preparation of 4-fluoro-4-(hydroxymethyl)piperidine-1-carboxylic acid phenethyl ester (F11)

[0045] According to the method for synthesizing F1, the benzyl group in the starting material is replaced with phenethyl to obtain compound F11. The total yield is 23%.

[0046] Implementation Case 12 Preparation of ethyl 4-fluoro-4-(hydroxymethyl)piperidine-1-carboxylate (F12)

[0047] According to the method for synthesizing F1, the benzyl group in the starting material is replaced by ethyl to obtain compound F12. The total yield is 11%.

[0048] Example 13 Preparation of 1H-indol-5-ylmethyl 4-fluoro-4-(hydroxymethyl)piperidine-1-carboxylate (F13)

[0049] According to the method for synthesizing F1, the benzyl group in the starting material is replaced by ethyl to obtain compound F13. The total yield is 19%.

[0050] Implementation Case 14 Preparation of 4-bromobenzyl 4-fluoro-4-(hydroxymethyl)piperidine-1-carboxylate (F14)

[0051] According to the method for synthesizing F1, the phenyl group in the starting material is replaced with 4-bromophenyl to obtain compound F14. The total yield is 25%.

[0052] Implementation Case 15 Preparation of 4-trifluoromethylbenzyl 4-fluoro-4-(hydroxymethyl)piperidine-1-carboxylate (F15)

[0053] According to the method for synthesizing F1, the phenyl group in the starting material is replaced with 4-trifluoromethylphenyl to obtain compound F15. The total yield is 17%.

[0054] Implementation Case 16 Preparation of 3,5-dimethoxybenzyl 4-fluoro-4-(hydroxymethyl)piperidine-1-carboxylate (F16)

[0055] According to the method for synthesizing F1, the phenyl group in the starting material was replaced with 3,5-dimethoxyphenyl to obtain compound F16. The total yield was 23%.

[0056] Implementation Case 17 Preparation of 4-(4-fluoro-4-(hydroxymethyl)piperidin-1-carbonyloxy)methylbenzoic acid (F17)

[0057] According to the method for synthesizing F1, the phenyl group in the starting material is replaced with 4-phenyl carboxylate to obtain compound F17. The total yield is 12%.

[0058] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A method for preparing a key intermediate of a lysine-specific demethylase 1 (LSD1) inhibitor, characterized in that: The intermediate structure is: ， in: R1 is selected from the group consisting of ethyl, benzyl, phenyl, cyclohexylmethyl, 4-pyridylmethyl, phenylethyl, 1H-indol-5-ylmethyl, 2-thienylmethyl, 2-furylmethyl, 4-fluorophenylmethyl, 4-chlorophenylmethyl, 4-bromophenylmethyl, 4-methoxyphenyl, 4-trifluoromethylphenylmethyl, 3,5-dimethoxyphenylmethyl, 4-formylphenylmethyl, cyclopentylmethyl, cyclobutylmethyl, 4-piperidinylmethyl, 3-chlorophenylmethyl, 2-chlorophenylmethyl, or 4-tert-butylphenylmethyl; R2 is selected from: methyl; Wherein: n is 0-2, when n is 0, it means there is no methyl substitution on the ring; The intermediate preparation route is: ， The intermediate preparation method is: Step 1, esterification reaction: Compound A reacts with a symmetrical carbonylation reagent X to generate an asymmetrical carbonate compound B; Step 2: Amine ester exchange reaction: the ester group in compound B is exchanged with the amine group in compound C to generate amide compound D; Step 3: Cyclization reaction, the carbonyl group in compound D is converted into the epoxy substituent in compound E; Step 4, fluorination reaction: Compound E is reacted with a fluorination agent to open the ring to generate a fluorine-substituted compound F; Wherein: X is selected from: phosgene, triphosgene, dimethyl carbonate, diethyl carbonate, N,N'-succinimidyl carbonate, di(p-nitrobenzene) carbonate.

2. The method for preparing a key intermediate of a lysine-specific demethylase 1 (LSD1) inhibitor according to claim 1, characterized in that: In the step 1, the symmetrical carbonylation reagent is phosgene, triphosgene, dimethyl carbonate, diethyl carbonate, N,N'-succinimidyl carbonate, and di(p-nitrobenzene) carbonate.

3. The method for preparing a key intermediate of a lysine-specific demethylase 1 (LSD1) inhibitor according to claim 1, characterized in that: In the step 1, the base is triethylamine, pyridine, 4-dimethylaminopyridine, N,N-diisopropylethylamine, potassium carbonate, sodium carbonate, sodium bicarbonate, sodium acetate; and the solvent is tetrahydrofuran, 2-methyltetrahydrofuran, acetonitrile, dichloromethane, toluene, dimethylformamide, methyl tert-butyl ether or dioxane.

4. The method for preparing a key intermediate of a lysine-specific demethylase 1 (LSD1) inhibitor according to claim 1, characterized in that: The reaction temperature of step 1 is 0-55°C.

5. The method for preparing a key intermediate of a lysine-specific demethylase 1 (LSD1) inhibitor according to claim 1, characterized in that: The base in the second amine ester exchange reaction is triethylamine, pyridine, 4-dimethylaminopyridine, N,N-diisopropylethylamine, potassium carbonate, sodium carbonate, sodium bicarbonate, sodium acetate; the solvent in the second step is tetrahydrofuran, 2-methyltetrahydrofuran, acetonitrile, dichloromethane, toluene, dimethylformamide, methyl tert-butyl ether or dioxane.

6. The method for preparing a key intermediate of a lysine-specific demethylase 1 (LSD1) inhibitor according to claim 1, characterized in that: The reaction temperature in step 2 is 0-55°C.

7. The method for preparing a key intermediate of a lysine-specific demethylase 1 (LSD1) inhibitor according to claim 1, characterized in that: The methylating agent in step 3 is trimethylsulfonium iodide, trimethylsulfonium bromide, dibromomethane, chloroiodomethane, chlorobromomethane, phenyldimethylmethanesulfonate selenium, trimethylsulfoxide iodide, trimethylsulfoxide bromide, trimethylsilane or dimethyl-N-(p-toluenesulfonyl)sulfoxime.

8. The method for preparing a key intermediate of a lysine-specific demethylase 1 (LSD1) inhibitor according to claim 1, characterized in that: In the step 3, the base is potassium hydroxide, butyl lithium, sodium hydride, sodium tert-butoxide, potassium tert-butoxide; and the solvent is dimethyl sulfoxide, tetrahydrofuran, acetonitrile or ethylene glycol dimethyl ether.

9. The method for preparing a key intermediate of a lysine-specific demethylase 1 (LSD1) inhibitor according to claim 1, characterized in that: In the fluorination reaction in step 4, the fluorination reagent is pyridine hydrofluoric acid, tetrabutylammonium fluoride, boron trifluoride etherate, and potassium difluoride.

10. The method for preparing a key intermediate of a lysine-specific demethylase 1 (LSD1) inhibitor according to claim 1, characterized in that: The solvent in step 4 is tetrahydrofuran, toluene, dimethylformamide, dimethyl sulfoxide or dichloromethane.

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