A long-acting derivative of baricitinib and methods of making and using the same

Abstract

This invention relates to compounds of Formula I or salts thereof. The invention also provides the application of Formula I in the preparation of medicaments for treating JAK-related autoimmune diseases, inflammatory diseases, or cancers, which exhibit significant stability, maintain effective blood concentrations for a certain period, thereby prolonging the drug administration cycle, improving patient compliance, and reducing side effects caused by rapid drug release.

Description

Technical Field

[0001] This invention relates to the field of medicinal chemistry, specifically to a crystalline form of a baricitinib prodrug derivative, a method for preparing the same, and to pharmaceutical formulations thereof and their medicinal uses. Background Technology

[0002] Alopecia areata is an autoimmune disease characterized by rapid loss of hair, eyebrows, and eyelashes. Its global prevalence is approximately 2%. Most patients with alopecia areata are relatively young, with up to 66% under the age of 30. Patients with alopecia areata have an increased overall risk of developing other autoimmune diseases. Treatment options for alopecia areata are limited, currently including corticosteroids and immunosuppressants. The Chinese Alopecia Areata Treatment Guidelines (2019) recommend topical application of potent corticosteroid creams for severe alopecia areata, and systemic treatments include corticosteroids and immunosuppressants (cyclosporine). However, the effectiveness of treatment for severe alopecia areata varies, and long-term use of corticosteroids has significant side effects, such as moon face and osteoporosis, therefore long-term use is not recommended. Immunosuppressant therapy is effective for some patients with alopecia areata, but it has relatively more adverse reactions, higher costs, and a higher relapse rate after discontinuation. Janus kinase (JAK) inhibitors can inhibit various inflammatory factors and are effective even in patients unresponsive to corticosteroids and traditional immunosuppressants, having a direct effect of immunosuppression and inducing the hair follicle cycle to enter the growth phase. Baricitinib is an oral anti-inflammatory drug developed by Eli Lilly and Incyte. In February 2017, it was approved for marketing in the European Union as the first JAK inhibitor for the treatment of rheumatoid arthritis. To date, the FDA has approved baricitinib tablets for the treatment of rheumatoid arthritis, atopic dermatitis, and severe alopecia areata. In China, baricitinib was approved for marketing in 2019 for adult patients with moderate to severe active rheumatoid arthritis who have not responded well to or are intolerant of one or more disease-modifying antirheumatic drugs. In March 2023, a new indication for baricitinib was approved by the National Medical Products Administration (NMPA) for the systemic treatment of severe alopecia areata in adults, marketed as Alermin. This is the first and only innovative targeted drug approved in China for the systemic treatment of severe alopecia areata. Alopecia areata is stubborn, difficult to treat, and prone to relapse. Previous treatments mainly involved oral and topical corticosteroids, with generally poor efficacy and significant side effects. The emergence of baricitinib undoubtedly brings a glimmer of hope to patients with alopecia areata.

[0003] Baricitinib is marketed in oral tablet form at doses of 1 mg, 2 mg, and 4 mg / tablet. It is a BCS Class III hypersoluble drug, exhibiting near 100% dissolution within 5 minutes in pH 1.2 media and greater than 85% dissolution within 15 minutes in pH 4.5 and pH 6.8 media. The absolute oral bioavailability of baricitinib is 79%. Following oral administration, baricitinib is rapidly absorbed, with a median tmax of approximately 1 hour (range 0.5–3.0 hours). Food intake reduces exposure by up to 14%, Cmax by up to 18%, and delays tmax by up to 0.5 hours. Dosing with meals is not clinically relevant to exposure. In patients with rheumatoid arthritis, the half-life is 12.5 hours. The median fasting Tmax ranged from 0.75 to 1.4 h, with extreme values ​​ranging from 0.5 to 3.0 h. The median postprandial Tmax ranged from 1.5 to 4.0 h, with extreme values ​​ranging from 0.5 to 6.0 h. Eating a high-fat meal delayed the time to peak drug efficacy to some extent. The intra-individual coefficient of variation was approximately 13-20%, requiring regular administration to maintain stable treatment levels.

[0004] Despite the potential benefits of baricitinib, the need for new compounds to treat the aforementioned diseases and conditions persists. However, baricitinib has relatively high water solubility and a short plasma concentration cycle, thus offering only limited duration of inhibition when used for selective JAK1 and JAK2 inhibitor therapy or pre-exposure prophylaxis. Furthermore, baricitinib is currently administered orally, and cases of diverticulitis, some complicated by gastrointestinal perforation, have been reported in clinical trials and post-marketing surveillance. In clinical trials, 21 cases of diverticulitis were reported in 3770 patients with rheumatoid arthritis (3 of whom had gastrointestinal perforation), with an incidence rate of 0.16 / 100 patients / year. As of December 31, 2019, 35 post-marketing cases of diverticulitis have been reported globally, including 5 cases complicated by gastrointestinal perforation. The onset of diverticulitis ranges from 6 days to 6 years, with most occurring after 90 days of treatment.

[0005] There is a desire for sustained-release drugs that reduce baricitinib exposure and decrease the distribution of side effects; however, no long-acting baricitinib formulations are available on the market. Therefore, there is a need for formulations that can prolong the duration of post-dose inhibition and for modified administration methods. The compounds and formulations of the present invention meet this need.

[0006] Prior art for baricitinib analogs and derivatives: WO2026002095, WO2022012693, WO2022133285, CN115806554, WO2018217700, WO2025252682, WO2023001045, CN114957260A, WO2026015691, KR2905826, WO2025191272, WO2025174243, US12390420, IN202441001153, WO202512175, KR2793673, CN119606887 The patents listed are CN119185575, WO2024119375, WO2023155905, CN114907354, WO2020034987, and CN107200742. Prodrugs, which are active pharmaceutical ingredients, typically undergo biotransformation in vivo to release the active drug. The use of prodrugs offers several advantages in drug development and therapy. Prodrugs can improve drug bioavailability by enhancing the drug's solubility, stability, and absorption. This can lead to better therapeutic outcomes and more predictable drug delivery. Furthermore, prodrugs can be designed to minimize side effects by targeting the drug's release to specific tissues or cells. This targeted delivery helps reduce the exposure of non-target tissues to the active drug, thereby reducing adverse reactions. Additionally, prodrugs can improve the chemical stability of drugs, leading to better formulation and storage.

[0007] An important aspect of prodrug development includes prolonging the duration of action: prodrugs can be designed to prolong or sustain the release of the active drug, resulting in a more durable therapeutic effect and potentially reducing the frequency of dosing. A significant benefit could be improved patient compliance or increased patient acceptance, leading to better adherence to treatment regimens. Furthermore, it can simplify dosing regimens and reduce the burden of medication use. To date, there are no sustained-release injectable prodrug formulations of baricitinib derivatives.

[0008] Therefore, given the advantages of long-acting formulations, the need to develop long-acting parenteral formulations of baricitinib remains unmet. Summary of the Invention

[0009] This invention relates to novel derivatives of baricitinib, a selective inhibitor of JAK-1 and JAK-2, which is currently under active development for the treatment of rheumatoid arthritis, moderate to severe plaque psoriasis, and inflammation. Baricitinib may also be suitable for the treatment of myeloproliferative disorders such as chronic myeloid leukemia, polycythemia vera, essential thrombocythemia, and essential myelofibrosis, as well as other inflammatory and autoimmune diseases, including multiple sclerosis, lupus erythematosus, type 1 diabetes mellitus, myasthenia gravis, transplant rejection, myocarditis, alopecia and other hair loss disorders, and dry eye, Sjögren's syndrome, and other eye-related diseases. This invention also provides complexes composed of the present invention and uses these compositions for the treatment of the aforementioned diseases.

[0010] This invention provides a long-acting prodrug by selectively modifying the structure of baricitinib. This drug is formulated for intramuscular and subcutaneous injection. After intramuscular or subcutaneous injection, a drug reservoir is formed in the body, from which the drug is slowly, continuously, and stably released and converted into baricitinib, thus exerting a long-acting effect. The inventors have surprisingly discovered that introducing substituents, at least on the pyrrole nitrogen of baricitinib, significantly alters the physical properties of the compound and improves its lipid solubility.

[0011] This invention is achieved using the following technical solution: The purpose of this invention is to overcome the shortcomings of the prior art and provide a compound of Formula I or a salt thereof:

[0012] Furthermore, the compound of formula I exists in crystalline form, and the X-ray powder diffraction of the crystal, expressed as a diffraction angle of 2θ±0.2°, has the following characteristic peaks: 19.56±0.2°, 19.58±0.2°, 19.60±0.2°, 19.62±0.2°, 19.64±0.2°, 19.68±0.2°, 19.74±0.2°, 19.76±0.2°, 19.80±0.2°, 19.92±0.2°, and 20.02±0.2°.

[0013] Furthermore, the X-ray powder diffraction of the crystal form of the compound represented by Formula I, expressed in terms of diffraction angles of 2θ ± 0.2°, exhibits the following characteristic peaks: Table 1 Characteristic Peaks

[0014] Furthermore, its X-ray powder diffraction pattern is shown in the attached figure; the DSC curve of the compound crystal shows that the onset temperature of the endothermic peak is 94.745±2℃ and the peak temperature is 100.69±2℃.

[0015] Furthermore, the preparation method of this crystal form includes: dissolving the compound of formula I in an organic solvent, stirring until dissolved, and cooling to crystallize.

[0016] The organic solvent is selected from acetonitrile or isopropyl ether or a mixture of the two; The preferred temperature reduction is 0–5°C.

[0017] The preparation method of the compounds of this invention adopts a generally known preparation method. The purity and structure of the prepared compounds were confirmed by chromatographic and spectroscopic analysis. The chromatographic analysis conditions are shown in Table 2. Table 2 Chromatographic conditions

[0018] The typical chromatograms and spectra are shown in the attached figure.

[0019] Another object of the present invention is a pharmaceutical composition comprising a baricitinib derivative of formula I as described in claim 1, or a salt thereof, and a pharmaceutically acceptable carrier. It is formulated for intramuscular, intradermal, or subcutaneous injection. The injectable formulation is prepared from the active ingredient of formula I and related pharmaceutical excipients according to pharmaceutically acceptable methods, including pharmaceutically necessary excipients such as suspending agents, antioxidants, stabilizers, wetting agents, and preservatives. The injectable solution of the present invention can be an aqueous suspension, an oil-based injection, or a lyophilized solution, for use in the preparation of remedies for the treatment of JAK-related autoimmune diseases, inflammatory diseases, or cancers.

[0020] The key points of this invention are: The compound of this invention is the hydroxymethyl decanoate of baricitinib, which has limited solubility in water. Baricitinib has a water solubility of 0.357–0.46 mg / mL at physiological pH, while the compound of this invention has a water solubility of less than 0.003 mg / mL at physiological pH. Furthermore, this compound is crystalline, which helps prolong the inhibitory time, and it can be administered intramuscularly or subcutaneously as a suspension in a drug-approved carrier, avoiding gastrointestinal side effects. It exhibits excellent stability and pharmacokinetic characteristics, along with low toxicity. Attached Figure Description

[0021] Figure 1 This is the structure of the compound of formula I.

[0022] Figure 2 HPLC for compound of formula I.

[0023] Figure 3 This is the hydrogen spectrum of compound I.

[0024] Figure 4 This is the carbon spectrum of compound I.

[0025] Figure 5LC-MS of compound of formula I.

[0026] Figure 6 The infrared spectrum is for compound of formula I.

[0027] Figure 7 The XRD pattern is shown for compound I.

[0028] Figure 8 The DSC is for compound of formula I.

[0029] Figure 9 TGA is the compound of formula I.

[0030] Figure 10 The results are from pharmacokinetic studies of compound I. Detailed Implementation

[0031] The following embodiments can further describe the present invention; however, these embodiments should not be construed as limiting the scope of the present invention.

[0032] General formula for preparation reaction:

[0033] Synthetic Example 1: Preparation of Formula I Decanoyloxymethylbaricitinib Step 1: 20.0 g baricitinib, 35.47 g paraformaldehyde, 1.31 g DMAP, and 100 ml DMF were added to a 500 ml reaction flask and heated to 50–60 °C for 16 hours. After the reaction was complete, the mixture was filtered, and the filtrate was washed three times with 300 ml of dichloromethane and 200 ml of water (3 times each). The solution was dried over anhydrous sodium sulfate, concentrated, and recrystallized from 120 ml of methanol to obtain 16.81 g of a white solid (hydroxymethyl baricitinib).

[0034] Step 2: 6.80 g of hydroxymethylbacitinib, 5.12 g of triethylamine, and 34 ml of dichloromethane were added to a 50 ml reaction flask, and the temperature was lowered to 0–5 °C. 9.24 g of decanoyl chloride was slowly added dropwise, with the addition temperature not exceeding 10 °C. After the addition was complete, the temperature was raised to room temperature, and the reaction was stirred for 3 hours. After the reaction was complete, 400 ml of dichloromethane was added, and the mixture was washed three times with 300 ml of water (3 x 3 ml). The mixture was dried over anhydrous sodium sulfate, concentrated, and purified by column chromatography (eluent: PE:EA = 10:1) to obtain 5.3 g of a colorless, transparent oily substance (decanoyloxymethylbacitinib). 20 ml of isopropyl ether was added, and the mixture was stirred until dissolved. The mixture was cooled to 0–5 °C and allowed to crystallize overnight. The crystals were filtered and dried to obtain 3.30 g of a white solid. The HPLC purity was 99.9%, and the structure was confirmed by 1H NMR, 1C NMR, mass spectrometry, infrared spectroscopy, X-ray diffraction, DSC, and TG.

[0035] Synthetic Example 2: Preparation of Formula I Decanoyloxymethylbaricitinib Step 1: 20.0 g baricitinib, 35.47 g paraformaldehyde, 1.31 g DMAP, and 100 ml DMF were added to a 500 ml reaction flask and heated to 50–60 °C for 16 hours. After the reaction was complete, the mixture was filtered, and the filtrate was washed three times with 300 ml of dichloromethane and 200 ml of water (3 times each). The solution was dried over anhydrous sodium sulfate, concentrated, and recrystallized from 100 ml of methanol to obtain 16.59 g of a white solid (hydroxymethyl baricitinib).

[0036] Step 2: Add 6.50g of hydroxymethylbaricitinib, 4.90g of triethylamine, and 30ml of dichloromethane to a 50ml reaction flask and cool to 0-5℃. Slowly add 8.84g of decanoyl chloride, with the addition temperature not exceeding 10℃. After the addition is complete, heat to room temperature and stir for 3 hours. After the reaction is complete, add 400ml of dichloromethane, wash three times with 300ml of water, dry with anhydrous sodium sulfate, concentrate, and pass through a column (eluent: PE:EA = 10:1) to obtain 5.12g of colorless, transparent oil (decanoyloxymethylbaricitinib). Add 20ml of acetonitrile, cool to 0-5℃ and crystallize overnight. Filter, dry, and obtain 3.42g of white solid.

[0037] Other control synthesis examples Comparative Synthesis Example 1: Preparation of Baricitinib Lauroyl 2.0 g baricitinib, 3.55 g paraformaldehyde, 0.13 g DMAP, and 20 ml DMF were added to a 50 ml reaction flask and heated to 50–60 °C for 6 hours. After the reaction was complete, the mixture was filtered, and the filtrate was washed three times with 200 ml of water (3 x 200 ml), dried over anhydrous sodium sulfate, concentrated, and purified by column chromatography (eluent: PE:EA = 2:1) to obtain 1.81 g of a white solid (hydroxymethyl baricitinib).

[0038] 0.80 g of hydroxymethylbaricitinib, 0.22 g of triethylamine, and 20 ml of dichloromethane were added to a 50 ml reaction flask, and the mixture was cooled to 0–5 °C. 0.48 g of lauroyl chloride was slowly added dropwise, with the addition temperature not exceeding 10 °C. After the addition was complete, the mixture was heated to room temperature and stirred for 1 hour. After the reaction was complete, the mixture was washed three times with 10 ml of water, dried over anhydrous sodium sulfate, concentrated, and purified by column chromatography (eluent: PE:EA = 10:1) to obtain 0.6 g of a colorless, transparent oil (lauroylbaricitinib).

[0039] Comparative Synthesis Example 2: Preparation of Baricitinib Lauroyl 2.0 g baricitinib, 3.55 g paraformaldehyde, 5.25 g cesium carbonate, and 20 ml DMF were added to a 50 ml reaction flask and heated to 50–60 °C for 10 hours. After the reaction was complete, the mixture was filtered, and the filtrate was washed three times with 200 ml of water (3 x 200 ml), dried over anhydrous sodium sulfate, concentrated, and purified by column chromatography (eluent: PE:EA = 2:1) to obtain 1.31 g of a white solid (hydroxymethyl baricitinib).

[0040] 0.30 g of hydroxymethylbaricitinib, 0.08 g of triethylamine, and 20 ml of dichloromethane were added to a 50 ml reaction flask, and the mixture was cooled to 0–5 °C. 0.18 g of lauroyl chloride was slowly added dropwise, with the addition temperature not exceeding 10 °C. After the addition was complete, the mixture was heated to room temperature and stirred for 1 hour. After the reaction was complete, the mixture was washed three times with 10 ml of water, dried over anhydrous sodium sulfate, concentrated, and purified by column chromatography (eluent: PE:EA = 10:1) to obtain 0.20 g of a colorless, transparent oil (lauroylbaricitinib).

[0041] Comparative Synthesis Example 3: Preparation of Baricitinib Lauroyl 2.0 g baricitinib, 3.55 g paraformaldehyde, 1.13 g pyridine, and 20 ml DMF were added to a 50 ml reaction flask and heated to 50–60 °C for 5 hours. After the reaction was complete, the mixture was filtered, and the filtrate was washed three times with 200 ml of water (3 x 200 ml), dried over anhydrous sodium sulfate, concentrated, and purified by column chromatography (eluent: PE:EA = 2:1) to obtain 1.75 g of white solid (hydroxymethyl baricitinib).

[0042] 0.70 g of hydroxymethylbaricitinib, 0.22 g of triethylamine, and 20 ml of dichloromethane were added to a 50 ml reaction flask, and the mixture was cooled to 0–5 °C. 0.48 g of lauroyl chloride was slowly added dropwise, with the addition temperature not exceeding 10 °C. After the addition was complete, the mixture was heated to room temperature and stirred for 1 hour. After the reaction was complete, the mixture was washed three times with 10 ml of water, dried over anhydrous sodium sulfate, concentrated, and purified by column chromatography (eluent: PE:EA = 10:1) to obtain 0.53 g of a colorless, transparent oil (lauroylbaricitinib).

[0043] Comparative Synthesis Example 4: Preparation of Baricitinib Lauroyl 2.0 g baricitinib, 2.55 g paraformaldehyde, 0.13 g DMAP, and 20 ml DMF were added to a 50 ml reaction flask and heated to 50–60 °C for 5 hours. After the reaction was complete, the mixture was filtered, and the filtrate was washed three times with 200 ml of water (3 x 200 ml), dried over anhydrous sodium sulfate, concentrated, and purified by column chromatography (eluent: PE:EA = 2:1) to give 1.65 g of a white solid (hydroxymethyl baricitinib), with a yield of 46.29%.

[0044] 0.60 g of hydroxymethylbaricitinib, 0.22 g of triethylamine, and 20 ml of dichloromethane were added to a 50 ml reaction flask, and the mixture was cooled to 0–5 °C. 0.48 g of lauroyl chloride was slowly added dropwise, with the addition temperature not exceeding 10 °C. After the addition was complete, the mixture was heated to room temperature and stirred for 1 hour. After the reaction was complete, the mixture was washed three times with 10 ml of water, dried over anhydrous sodium sulfate, concentrated, and purified by column chromatography (eluent: PE:EA = 10:1) to obtain 0.53 g of a colorless, transparent oil (lauroylbaricitinib).

[0045] Comparative Synthesis Example 5: Preparation of Baricitinib Lauroyl 34.40 g of baricitinib, 61.00 g of paraformaldehyde, 2.26 g of DMAP, and 170 ml of DMF were added to a 500 ml reaction flask and heated to 50–60 °C for 16 hours. After the reaction was completed, the mixture was filtered, and the filtrate was washed three times with 200 ml of water (3 times each), dried over anhydrous sodium sulfate, concentrated, dissolved in 500 ml of methanol, concentrated to approximately 150 ml, cooled to 0–5 °C for 2 hours to crystallize, and filtered to obtain 28.84 g of white crystalline solid (hydroxymethyl baricitinib).

[0046] 6.50 g of hydroxymethylbaricitinib, 4.90 g of triethylamine, and 30 ml of dichloromethane were added to a 50 ml reaction flask, and the mixture was cooled to 0–5 °C. 8.84 g of lauroyl chloride was slowly added dropwise, with the addition temperature not exceeding 10 °C. After the addition was complete, the mixture was heated to room temperature and stirred for 3 hours. After the reaction was complete, 400 ml of dichloromethane was added, and the mixture was washed three times with 300 ml of water (3 x 3 ml). The solution was dried over anhydrous sodium sulfate, concentrated, and purified by column chromatography (eluent: PE:EA = 10:1) to obtain 5.25 g of a colorless, transparent oil (lauroylbaricitinib).

[0047] Comparative Synthesis Example 6: Preparation of Formula I Decanoyloxymethylbaricitinib 100g baricitinib, 177.33g paraformaldehyde, 6.56g DMAP, and 6000ml DMF were added to a 1000ml reaction flask and heated to 50-60℃ for 24 hours. After the reaction was completed, the mixture was filtered, and the filtrate was washed three times with 1000ml dichloromethane and 500ml water (3 times each). The solution was dried over anhydrous sodium sulfate, concentrated, dissolved in 1000ml methanol, and concentrated to approximately 500ml. The solution was cooled to 0-5℃ for 2 hours to crystallize, and then filtered to obtain 69.26g of white solid (hydroxymethyl baricitinib).

[0048] 5.0 g of hydroxymethylbaricitinib, 3.76 g of triethylamine, and 25 ml of dichloromethane were added to a 50 ml reaction flask, and the mixture was cooled to 0–5 °C. 5.92 g of decanoyl chloride was slowly added dropwise, with the addition temperature not exceeding 10 °C. After the addition was complete, the mixture was heated to room temperature and stirred for 3 hours. After the reaction was complete, 200 ml of dichloromethane was added, and the mixture was washed three times with 100 ml of water (3 times). The solution was dried over anhydrous sodium sulfate, concentrated, and purified by column chromatography (eluent: PE:EA = 10:1) to obtain 4.1 g of a colorless, foamy solid. This solid was dissolved in 15 ml of methanol, and the mixture was cooled to 0–5 °C to crystallize; no solid precipitated.

[0049] Comparative Synthesis Example 7: Preparation of Formula I Decanoyloxymethylbaricitinib 100g baricitinib, 177.33g paraformaldehyde, 6.56g DMAP, and 6000ml DMF were added to a 1000ml reaction flask and heated to 50-60℃ for 24 hours. After the reaction was completed, the mixture was filtered, and the filtrate was washed three times with 1000ml dichloromethane and 500ml water (3 times each). The solution was dried over anhydrous sodium sulfate, concentrated, dissolved in 1000ml methanol, and concentrated to approximately 500ml. The solution was cooled to 0-5℃ for 2 hours to crystallize, and then filtered to obtain 69.26g of white solid (hydroxymethyl baricitinib).

[0050] 5.0 g of hydroxymethylbaricitinib, 3.76 g of DIPEA, and 25 ml of dichloromethane were added to a 50 ml reaction flask, and the mixture was cooled to 0–5 °C. 5.92 g of decanoyl chloride was slowly added dropwise, with the addition temperature not exceeding 10 °C. After the addition was complete, the mixture was heated to room temperature and stirred for 3 hours. After the reaction was complete, 200 ml of dichloromethane was added, and the mixture was washed three times with 100 ml of water (3 times). The solution was dried over anhydrous sodium sulfate, concentrated, and purified by column chromatography (eluent: PE:EA = 10:1) to obtain 4.05 g of a colorless, foamy solid. This solid was dissolved in 15 ml of isopropanol, and the mixture was cooled to 0–5 °C to crystallize; no solid precipitated.

[0051] Comparative Synthesis Example 8: Preparation of Formula I Decanoyloxymethylbaricitinib 100g baricitinib, 177.33g paraformaldehyde, 6.56g DMAP, and 6000ml DMF were added to a 1000ml reaction flask and heated to 50-60℃ for 24 hours. After the reaction was completed, the mixture was filtered, and the filtrate was washed three times with 1000ml dichloromethane and 500ml water (3 times each). The filtrate was dried over anhydrous sodium sulfate, concentrated, dissolved in 1000ml methanol, and concentrated to approximately 500ml. The solution was cooled to 0-5℃ for 2 hours to crystallize, and then filtered to obtain 69.26g of a white solid (hydroxymethyl baricitinib).

[0052] 5.0 g of hydroxymethylbaricitinib, 3.16 g of pyridine, and 25 ml of dichloromethane were added to a 50 ml reaction flask, and the mixture was cooled to 0–5 °C. 5.92 g of decanoyl chloride was slowly added dropwise, with the addition temperature not exceeding 10 °C. After the addition was complete, the mixture was heated to room temperature and stirred for 3 hours. After the reaction was complete, 200 ml of dichloromethane was added, and the mixture was washed three times with 100 ml of water (3 times). The solution was dried over anhydrous sodium sulfate, concentrated, and purified by column chromatography (eluent: PE:EA = 10:1) to obtain 4.31 g of a colorless, foamy solid. This solid was dissolved in 15 ml of ethanol, and the mixture was cooled to 0–5 °C to crystallize; no solid precipitated.

[0053] Comparative Synthesis Example 9: Preparation of Formula I Decanoyloxymethylbaricitinib 100g baricitinib, 177.33g paraformaldehyde, 6.56g DMAP, and 6000ml DMF were added to a 1000ml reaction flask and heated to 50-60℃ for 24 hours. After the reaction was completed, the mixture was filtered, and the filtrate was washed three times with 1000ml dichloromethane and 500ml water (3 times each). The filtrate was dried over anhydrous sodium sulfate, concentrated, dissolved in 1000ml methanol, and concentrated to approximately 500ml. The solution was cooled to 0-5℃ for 2 hours to crystallize, and then filtered to obtain 69.26g of a white solid (hydroxymethyl baricitinib), with a yield of 64.13%.

[0054] 5.0 g of hydroxymethylbaricitinib, 3.22 g of DBU, and 25 ml of dichloromethane were added to a 50 ml reaction flask, and the mixture was cooled to 0–5 °C. 5.92 g of decanoyl chloride was slowly added dropwise, with the addition temperature not exceeding 10 °C. After the addition was complete, the mixture was heated to room temperature and stirred for 3 hours. After the reaction was complete, 200 ml of dichloromethane was added, and the mixture was washed three times with 100 ml of water (3 times). The mixture was dried over anhydrous sodium sulfate, concentrated, and purified by column chromatography (eluent: PE:EA = 10:1) to obtain 3.96 g of a colorless, foamy solid. This solid was dissolved in 15 ml of ethyl acetate, and then 15 ml of petroleum ether was slowly added. The mixture was cooled to 0–5 °C to crystallize, and a viscous solid precipitated out.

[0055] Comparative Synthesis Example 10: Preparation of Baricitinib Hexanoyl 100g baricitinib, 177.33g paraformaldehyde, 6.56g DMAP, and 6000ml DMF were added to a 1000ml reaction flask and heated to 50-60℃ for 24 hours. After the reaction was completed, the mixture was filtered, and the filtrate was washed three times with 1000ml dichloromethane and 500ml water (3 times each). The solution was dried over anhydrous sodium sulfate, concentrated, dissolved in 1000ml methanol, and concentrated to approximately 500ml. The solution was cooled to 0-5℃ for 2 hours to crystallize, and then filtered to obtain 69.26g of white solid (hydroxymethyl baricitinib).

[0056] 5.0 g of hydroxymethylbaricitinib, 3.76 g of triethylamine, and 25 ml of dichloromethane were added to a 50 ml reaction flask, and the mixture was cooled to 0–5 °C. 4.18 g of hexanoyl chloride was slowly added dropwise, with the addition temperature not exceeding 10 °C. After the addition was complete, the mixture was heated to room temperature and stirred for 3 hours. After the reaction was complete, 200 ml of dichloromethane was added, and the mixture was washed three times with 100 ml of water (3 times). The solution was dried over anhydrous sodium sulfate, concentrated, and purified by column chromatography (eluent: PE:EA = 10:1) to obtain 4.3 g of a colorless, foamy solid (hexanoylbaricitinib).

[0057] Comparative Synthesis Example 11: Preparation of Baricitinib Hexanoyl 100g baricitinib, 177.33g paraformaldehyde, 6.56g DMAP, and 6000ml DMF were added to a 1000ml reaction flask and heated to 50-60℃ for 24 hours. After the reaction was completed, the mixture was filtered, and the filtrate was washed three times with 1000ml dichloromethane and 500ml water (3 times each). The filtrate was dried over anhydrous sodium sulfate, concentrated, dissolved in 1000ml methanol, and concentrated to approximately 500ml. The solution was cooled to 0-5℃ for 2 hours to crystallize, and then filtered to obtain 69.26g of a white solid (hydroxymethyl baricitinib).

[0058] 5.0 g of hydroxymethylbaricitinib, 3.56 g of DBU, and 25 ml of dichloromethane were added to a 50 ml reaction flask, and the mixture was cooled to 0–5 °C. 4.18 g of hexanoyl chloride was slowly added dropwise, with the addition temperature not exceeding 10 °C. After the addition was complete, the mixture was heated to room temperature and stirred for 3 hours. After the reaction was complete, 200 ml of dichloromethane was added, and the mixture was washed three times with 100 ml of water (3 times). The solution was dried over anhydrous sodium sulfate, concentrated, and purified by column chromatography (eluent: PE:EA = 10:1) to obtain 3.3 g of a colorless, foamy solid (hexanoylbaricitinib).

[0059] Comparative Synthesis Example 12: Preparation of Baricitinib Hexanoyl 100g baricitinib, 177.33g paraformaldehyde, 6.56g DMAP, and 6000ml DMF were added to a 1000ml reaction flask and heated to 50-60℃ for 24 hours. After the reaction was completed, the mixture was filtered, and the filtrate was washed three times with 1000ml dichloromethane and 500ml water (3 times each). The filtrate was dried over anhydrous sodium sulfate, concentrated, dissolved in 1000ml methanol, and concentrated to approximately 500ml. The solution was cooled to 0-5℃ for 2 hours to crystallize, and then filtered to obtain 69.26g of a white solid (hydroxymethyl baricitinib), with a yield of 64.13%.

[0060] 5.0 g of hydroxymethylbaricitinib, 3.23 g of DIPEA, and 25 ml of dichloromethane were added to a 50 ml reaction flask, and the mixture was cooled to 0–5 °C. 4.18 g of hexanoyl chloride was slowly added dropwise, with the addition temperature not exceeding 10 °C. After the addition was complete, the mixture was heated to room temperature and stirred for 3 hours. After the reaction was complete, 200 ml of dichloromethane was added, and the mixture was washed three times with 100 ml of water (3 times). The solution was dried over anhydrous sodium sulfate, concentrated, and purified by column chromatography (eluent: PE:EA = 10:1) to obtain 3.44 g of a colorless, foamy solid (hexanoylbaricitinib).

[0061] Comparative Synthesis Example 13: Preparation of Baricitinib Hexanoyl 100g baricitinib, 177.33g paraformaldehyde, 6.56g DMAP, and 6000ml DMF were added to a 1000ml reaction flask and heated to 50-60℃ for 24 hours. After the reaction was completed, the mixture was filtered, and the filtrate was washed three times with 1000ml dichloromethane and 500ml water (3 times each). The filtrate was dried over anhydrous sodium sulfate, concentrated, dissolved in 1000ml methanol, and concentrated to approximately 500ml. The solution was cooled to 0-5℃ for 2 hours to crystallize, and then filtered to obtain 69.26g of a white solid (hydroxymethyl baricitinib).

[0062] 5.0 g of hydroxymethylbaricitinib, 3.89 g of pyridine, and 25 ml of dichloromethane were added to a 50 ml reaction flask, and the mixture was cooled to 0–5 °C. 4.18 g of hexanoyl chloride was slowly added dropwise, with the addition temperature not exceeding 10 °C. After the addition was complete, the mixture was heated to room temperature and stirred for 3 hours. After the reaction was complete, 200 ml of dichloromethane was added, and the mixture was washed three times with 100 ml of water (3 times). The solution was dried over anhydrous sodium sulfate, concentrated, and purified by column chromatography (eluent: PE:EA = 10:1) to obtain 3.88 g of a colorless, foamy solid (hexanoylbaricitinib).

[0063] Comparative Synthesis Example 14: Preparation of Palmitoyl Baricitinib 100g baricitinib, 177.33g paraformaldehyde, 6.56g DMAP, and 6000ml DMF were added to a 1000ml reaction flask and heated to 50-60℃ for 24 hours. After the reaction was completed, the mixture was filtered, and the filtrate was washed three times with 1000ml dichloromethane and 500ml water (3 times each). The filtrate was dried over anhydrous sodium sulfate, concentrated, dissolved in 1000ml methanol, and concentrated to approximately 500ml. The solution was cooled to 0-5℃ for 2 hours to crystallize, and then filtered to obtain 69.26g of a white solid (hydroxymethyl baricitinib).

[0064] 5.0 g of hydroxymethylbaricitinib, 3.76 g of triethylamine, and 25 ml of dichloromethane were added to a 50 ml reaction flask, and the mixture was cooled to 0–5 °C. 6.18 g of palmitoyl chloride was slowly added dropwise, with the addition temperature not exceeding 10 °C. After the addition was complete, the mixture was heated to room temperature and stirred for 3 hours. After the reaction was complete, 200 ml of dichloromethane was added, and the mixture was washed three times with 100 ml of water (3 times). The solution was dried over anhydrous sodium sulfate, concentrated, and purified by column chromatography (eluent: PE:EA = 10:1) to obtain 5.3 g of a colorless oil (palmitoylbaricitinib).

[0065] Comparative Synthesis Example 15: Preparation of Palmitoyl Baricitinib 100g baricitinib, 177.33g paraformaldehyde, 6.56g DMAP, and 6000ml DMF were added to a 1000ml reaction flask and heated to 50-60℃ for 24 hours. After the reaction was completed, the mixture was filtered, and the filtrate was washed three times with 1000ml dichloromethane and 500ml water (3 times each). The filtrate was dried over anhydrous sodium sulfate, concentrated, dissolved in 1000ml methanol, and concentrated to approximately 500ml. The solution was cooled to 0-5℃ for 2 hours to crystallize, and then filtered to obtain 69.26g of a white solid (hydroxymethyl baricitinib).

[0066] 5.0 g of hydroxymethylbaricitinib, 3.56 g of DBU, and 25 ml of dichloromethane were added to a 50 ml reaction flask, and the mixture was cooled to 0–5 °C. 5.88 g of palmitoyl chloride was slowly added dropwise, with the addition temperature not exceeding 10 °C. After the addition was complete, the mixture was heated to room temperature and stirred for 3 hours. After the reaction was complete, 200 ml of dichloromethane was added, and the mixture was washed three times with 100 ml of water (3 times). The solution was dried over anhydrous sodium sulfate, concentrated, and purified by column chromatography (eluent: PE:EA = 10:1) to obtain 3.56 g of a colorless oil (palmitoylbaricitinib).

[0067] Comparative Synthesis Example 16: Preparation of Palmitoyl Baricitinib 100g baricitinib, 177.33g paraformaldehyde, 6.56g DMAP, and 6000ml DMF were added to a 1000ml reaction flask and heated to 50-60℃ for 24 hours. After the reaction was completed, the mixture was filtered, and the filtrate was washed three times with 1000ml dichloromethane and 500ml water (3 times each). The filtrate was dried over anhydrous sodium sulfate, concentrated, dissolved in 1000ml methanol, and concentrated to approximately 500ml. The solution was cooled to 0-5℃ for 2 hours to crystallize, and then filtered to obtain 69.26g of a white solid (hydroxymethyl baricitinib).

[0068] 5.0 g of hydroxymethylbaricitinib, 3.23 g of DIPEA, and 25 ml of dichloromethane were added to a 50 ml reaction flask, and the mixture was cooled to 0–5 °C. 4.18 g of hexanoyl chloride was slowly added dropwise, with the addition temperature not exceeding 10 °C. After the addition was complete, the mixture was heated to room temperature and stirred for 3 hours. After the reaction was complete, 200 ml of dichloromethane was added, and the mixture was washed three times with 100 ml of water (3 times). The solution was dried over anhydrous sodium sulfate, concentrated, and purified by column chromatography (eluent: PE:EA = 10:1) to obtain 3.44 g of a colorless oil (palmitoylbaricitinib).

[0069] Comparative Synthesis Example 17: Preparation of Palmitoyl Baricitinib 100g baricitinib, 177.33g paraformaldehyde, 6.56g DMAP, and 6000ml DMF were added to a 1000ml reaction flask and heated to 50-60℃ for 24 hours. After the reaction was completed, the mixture was filtered, and the filtrate was washed three times with 1000ml dichloromethane and 500ml water (3 times each). The filtrate was dried over anhydrous sodium sulfate, concentrated, dissolved in 1000ml methanol, and concentrated to approximately 500ml. The solution was cooled to 0-5℃ for 2 hours to crystallize, and then filtered to obtain 69.26g of a white solid (hydroxymethyl baricitinib).

[0070] 5.0 g of hydroxymethylbaricitinib, 3.89 g of pyridine, and 25 ml of dichloromethane were added to a 50 ml reaction flask, and the mixture was cooled to 0–5 °C. 6.88 g of palmitoyl chloride was slowly added dropwise, with the addition temperature not exceeding 10 °C. After the addition was complete, the mixture was heated to room temperature and stirred for 3 hours. After the reaction was complete, 200 ml of dichloromethane was added, and the mixture was washed three times with 100 ml of water (3 times). The solution was dried over anhydrous sodium sulfate, concentrated, and purified by column chromatography (eluent: PE:EA = 10:1) to obtain 3.66 g of a colorless oil (palmitoylbaricitinib).

[0071] Comparative Synthesis Example 18: Preparation of Baricitinib Lauroyl 34.40 g of baricitinib, 61.00 g of paraformaldehyde, 2.26 g of DMAP, and 170 ml of DMF were added to a 500 ml reaction flask and heated to 50–60 °C for 16 hours. After the reaction was completed, the mixture was filtered, and the filtrate was washed three times with 200 ml of water (3 times each), dried over anhydrous sodium sulfate, concentrated, dissolved in 500 ml of methanol, concentrated to approximately 150 ml, cooled to 0–5 °C for 2 hours to crystallize, and filtered to obtain 28.84 g of white crystalline solid (hydroxymethyl baricitinib).

[0072] 6.50 g of hydroxymethylbaricitinib, 4.90 g of triethylamine, and 30 ml of dichloromethane were added to a 50 ml reaction flask, and the mixture was cooled to 0–5 °C. 8.84 g of lauroyl chloride was slowly added dropwise, with the addition temperature not exceeding 10 °C. After the addition was complete, the mixture was heated to room temperature and stirred for 3 hours. After the reaction was complete, 400 ml of dichloromethane was added, and the mixture was washed three times with 300 ml of water (3 x 3 ml). The mixture was dried over anhydrous sodium sulfate, concentrated, and purified by column chromatography (eluent: PE:EA = 10:1) to obtain 5.32 g of a colorless, transparent oil (lauroylbaricitinib). 20 ml of acetone was added, and the mixture was cooled to -20–-10 °C and allowed to crystallize overnight; no solid precipitated.

[0073] Comparative Synthesis Example 19: Preparation of Baricitinib Lauroyl 34.40 g of baricitinib, 61.00 g of paraformaldehyde, 2.26 g of DMAP, and 170 ml of DMF were added to a 500 ml reaction flask and heated to 50–60 °C for 16 hours. After the reaction was completed, the mixture was filtered, and the filtrate was washed three times with 200 ml of water (3 times each), dried over anhydrous sodium sulfate, concentrated, dissolved in 500 ml of methanol, concentrated to approximately 150 ml, cooled to 0–5 °C for 2 hours to crystallize, and filtered to obtain 28.84 g of white crystalline solid (hydroxymethyl baricitinib).

[0074] 6.50 g of hydroxymethylbaricitinib, 4.90 g of triethylamine, and 30 ml of dichloromethane were added to a 50 ml reaction flask, and the mixture was cooled to 0–5 °C. 8.84 g of lauroyl chloride was slowly added dropwise, with the addition temperature not exceeding 10 °C. After the addition was complete, the mixture was heated to room temperature and stirred for 3 hours. After the reaction was complete, 400 ml of dichloromethane was added, and the mixture was washed three times with 300 ml of water (3 x 3 ml). The mixture was dried over anhydrous sodium sulfate, concentrated, and purified by column chromatography (eluent: PE:EA = 10:1) to obtain 5.27 g of a colorless, transparent oil (lauroylbaricitinib). 20 ml of methanol was added, and the mixture was cooled to -20–-10 °C and allowed to crystallize overnight; no solid precipitated.

[0075] Comparative Synthesis Example 20: Preparation of Baricitinib Lauroyl 34.40 g of baricitinib, 61.00 g of paraformaldehyde, 2.26 g of DMAP, and 170 ml of DMF were added to a 500 ml reaction flask and heated to 50–60 °C for 16 hours. After the reaction was completed, the mixture was filtered, and the filtrate was washed three times with 200 ml of water (3 times each), dried over anhydrous sodium sulfate, concentrated, dissolved in 500 ml of methanol, concentrated to approximately 150 ml, cooled to 0–5 °C for 2 hours to crystallize, and filtered to obtain 28.84 g of white crystalline solid (hydroxymethyl baricitinib).

[0076] 6.50 g of hydroxymethylbaricitinib, 4.90 g of triethylamine, and 30 ml of dichloromethane were added to a 50 ml reaction flask, and the mixture was cooled to 0–5 °C. 8.84 g of lauroyl chloride was slowly added dropwise, with the addition temperature not exceeding 10 °C. After the addition was complete, the mixture was heated to room temperature and stirred for 3 hours. After the reaction was complete, 400 ml of dichloromethane was added, and the mixture was washed three times with 300 ml of water (3 x 3 ml). The solution was dried over anhydrous sodium sulfate, concentrated, and purified by column chromatography (eluent: PE:EA = 10:1) to obtain 5.15 g of a colorless, transparent oil (lauroylbaricitinib). 20 ml of ethanol was added, and the mixture was cooled to -20–-10 °C and allowed to crystallize overnight; no solid precipitated.

[0077] Comparative Synthesis Example 21: Preparation of Baricitinib Lauroyl 34.40 g of baricitinib, 61.00 g of paraformaldehyde, 2.26 g of DMAP, and 170 ml of DMF were added to a 500 ml reaction flask and heated to 50–60 °C for 16 hours. After the reaction was completed, the mixture was filtered, and the filtrate was washed three times with 200 ml of water (3 times each), dried over anhydrous sodium sulfate, concentrated, dissolved in 500 ml of methanol, concentrated to approximately 150 ml, cooled to 0–5 °C for 2 hours to crystallize, and filtered to obtain 28.84 g of white crystalline solid (hydroxymethyl baricitinib).

[0078] 6.50 g of hydroxymethylbaricitinib, 4.90 g of triethylamine, and 30 ml of dichloromethane were added to a 50 ml reaction flask, and the mixture was cooled to 0–5 °C. 8.84 g of lauroyl chloride was slowly added dropwise, with the addition temperature not exceeding 10 °C. After the addition was complete, the mixture was heated to room temperature and stirred for 3 hours. After the reaction was complete, 400 ml of dichloromethane was added, and the mixture was washed three times with 300 ml of water (3 x 3 ml). The mixture was dried over anhydrous sodium sulfate, concentrated, and purified by column chromatography (eluent: PE:EA = 10:1) to obtain 5.10 g of a colorless, transparent oil (lauroylbaricitinib). 20 ml of ethyl acetate was added, and the mixture was cooled to -20–-10 °C and allowed to crystallize overnight; no solid precipitated.

[0079] Spectral analysis example: Formula I: Decanoyloxymethylbaricitinib MS (ESI): M+H + 556.2 1H-NMR (400 MHz, Chloroform-d) δ 8.95 (s, 1H), 8.59 (s, 1H), 8.38 (s,1H), 7.58 (s, 1H), 6.82 (dd, J = 3.9, 1.8 Hz, 1H), 6.30 (s, 2H), 4.68 (d, J =9.2 Hz, 2H), 4.30 (d, J = 9.3 Hz, 2H), 3.45 (s, 2H), 3.13 (q, J = 7.4 Hz, 2H), 2.38 (t, J = 7.5 Hz, 2H), 1.69~1.58 (m, 2H), 1.46 (t, J = 7.4 Hz, 3H),1.26 (s, 12H), 0.90 (t, J = 6.8 Hz, 3H). 13 C NMR (151 MHz, CDCl3): δ 173.66, 152.08, 151.95, 150.17, 140.71,129.80, 128.38, 122.83, 115.18, 114.48, 100.98, 65.49, 58.88, 56.09, 46.63,33.89,31.75, 29.28,29.12, 29.09, 28.89, 27.58, 24.57, 22.57, 14.05, 7.81. DSC: Crystalline compound, melting at 94.74℃~112.63℃; TGA: This product begins to decompose at approximately 170.10°C; XRD: This product is a crystalline compound; (Test conditions: XRD was performed on a Shimadzu 6100 diffractometer using Cu-Ka X-rays at a wavelength of 1.54 nm, 40 kV, and 30 mA. Before testing, the instrument was checked for performance using corundum. The test sample was placed on a non-reflective plate at room temperature. Test conditions: scan range 5-90°, 10° / min) Table 3. XRD pattern analysis of the compounds of this invention

[0080] Infrared spectrum (IR): Table 4. IR spectrum analysis of the compounds of this invention

[0081] Baricitinib lauroyl: MS (ESI): M+H+ 584.6 1 H-NMR (400 MHz, Chloroform-d) δ 8.94 (s, 1H), 8.60 (s, 1H), 8.38 (s,1H), 7.58 (s, 1H), 6.81 (dd, J = 3.9, 1.8 Hz, 1H), 6.29 (s, 2H), 4.66 (d, J =9.2 Hz, 2H), 4.30 (d, J = 9.3 Hz, 2H), 3.43 (s, 2H), 3.14 (q, J = 7.4 Hz, 2H), 2.35 (t, J = 7.5 Hz, 2H), 1.69~1.58 (m, 2H), 1.46 (t, J = 7.4 Hz, 3H),1.28 (s, 16H), 0.91 (t, J = 6.8 Hz, 3H). 13 C NMR (151 MHz, CDCl3): δ 173.67, 152.06, 151.98, 150.17, 140.71,129.90, 128.38, 122.84, 115.18, 114.49, 100.98, 65.49, 58.86, 56.12, 46.64,33.89,31.75, 29.28,29.12, 29.09, 28.89, 27.58, 24.57,24.16,23.99,22.57,14.05, 7.86. Baricitinib hexanoyl: MS (ESI): M+H + 450.3 1H-NMR (400 MHz, Chloroform-d) δ 8.94 (s, 1H), 8.60 (s, 1H), 8.36 (s,1H), 7.58 (s, 1H), 6.82 (dd, J = 3.9, 1.8 Hz, 1H), 6.31 (s, 2H), 4.67 (d, J =9.2 Hz, 2H), 4.30 (d, J = 9.3 Hz, 2H), 3.44 (s, 2H), 3.12 (q, J = 7.4 Hz,2H), 2.36 (t, J = 7.5 Hz, 2H), 1.69~1.58 (m, 2H), 1.46 (t, J = 7.4 Hz, 3H),1.27 (s, 4H), 0.92 (t, J = 6.8 Hz, 3H). 13 C NMR (151 MHz, CDCl3): δ 173.66, 152.08, 151.95, 150.17, 140.71,129.80, 128.38, 122.83, 115.18, 114.48, 100.98, 65.49, 58.88,46.63, 31.75,29.28,29.09, 28.89, 24.57, 22.57, 14.05, 7.81. Palmitoyl Baricitinib MS (ESI): M+H + 640.8 1 H-NMR (400 MHz, Chloroform-d) δ 8.94 (s, 1H), 8.56 (s, 1H), 8.39 (s,1H), 7.58 (s, 1H), 6.82 (dd, J = 3.9, 1.8 Hz, 1H), 6.27 (s, 2H), 4.67 (d, J =9.2 Hz, 2H), 4.30 (d, J = 9.3 Hz, 2H), 3.43 (s, 2H), 3.15 (q, J = 7.4 Hz,2H), 2.36 (t, J = 7.5 Hz, 2H), 1.69~1.58 (m, 2H), 1.43 (t, J = 7.4 Hz, 3H),1.27 (s, 24H), 0.90 (t, J = 6.8 Hz, 3H). 13C NMR (151 MHz, CDCl3): δ 173.57, 152.06, 151.99, 150.17, 140.71,129.90, 128.38, 122.84, 115.18, 114.49, 100.98, 65.49, 58.86, 56.10, 46.64,33.89,31.75, 29.28,29.12, 29.09, 28.89, 27.58, 24.57,24.44,24.16,24.11,23.99,23.88,22.57, 20.62, 14.05, 7.86. Physicochemical Testing Example 1: Comparison of Physicochemical Properties Table 5 Comparison of physicochemical properties of similar compounds

[0082] Physicochemical Testing Example 2: Stability Study The compounds of this invention may be used as active pharmaceutical ingredients (APIs) in the preparation of injectable solutions; therefore, storage is crucial. Impurities may be introduced or generated during storage, affecting the use of the API. Therefore, the stability of the API of this invention is investigated. Following the ICH guideline "Stability Testing of New APIs and Formulations," influencing factor tests were conducted.

[0083] 1. Test conditions: The high humidity test of this product was conducted at 25℃±2℃, RH: 75%±5%, and high temperature (60℃) with the inner and outer packaging removed for 30 days. The light exposure (total illuminance not less than 1.2×106Lux·hr) was also conducted with the inner and outer packaging removed.

[0084] 2. Sampling and testing: High temperature samples were taken at 5, 10 and 30 days; high humidity samples were taken at 5 and 10 days; light conditions samples were taken at 5 and 10 days.

[0085] 3. Observation results: See Table 6 below: Table 6: Factors affecting the stability of compounds (stability test)

[0086]

[0087] Conclusion: As shown in the table, the active pharmaceutical ingredient (API) of this invention is very stable under the relevant conditions, with no obvious impurities produced. In contrast, similar compounds exhibit significant known impurities, and their content limits far exceed the requirements for clinical pharmaceutical APIs. Furthermore, their stability shows a trend of degradation. This further demonstrates that the compounds of this invention have high crystalline purity and stable properties.

[0088] Example 3 of Physical and Chemical Tests: Determination of Water Solubility Take 500 μL of phosphate buffer (pH = 1.2, 4.5, 6.8 or 7.4) and add it to a glass bottle. Then add 5 mg of the compound powder, stopper the bottle, and place it on a mixer to mix evenly at room temperature for 24 h. Then perform vacuum filtration. After the filtrate is processed, the concentration of the compound is determined by LC / MS. The solubility results of the obtained compound are shown in Table 7: Table 7 Determination Results of the Water Solubility of the Compound

[0089] Conclusion: Compared with baricitinib, the compound obtained in this invention is extremely difficult to dissolve in water, and its water solubility changes very little at different pH values, which can be basically regarded as unchanged. This characteristic is particularly important in the development of pharmaceutical preparations. At the same time, when developing a suspension long-acting injection, there is almost no burst effect and very few side effects.

[0090] Test Example 4: Preliminary Pharmacokinetic Study in Rats 1 Test System 1.1 Information of Experimental Animals<000​​​​​​​​​​​​​​​​​Feed type: Compound feed for laboratory mice; Feeding method: Free access; Bedding name: Sterilized corn cob bedding; The supplier provides test reports for each batch to confirm the nutritional composition of the feed and the contaminant content of the feed and bedding.

[0094] 1.5 Drinking Water Information Type: Sterile drinking water; Water supply method: Animals drink water freely through dedicated water bottles; Water quality testing: Animal drinking water is tested by a professional testing agency at least once a year to ensure that the content of pollutants in the water will not affect the research results, and the water quality test report is regularly archived in the agency's archives.

[0095] 1.6 Quarantine and Adaptation Feeding: Quarantine and adaptability feeding for at least 5 days, and use after passing the quarantine.

[0096] 1.7 Veterinary Treatment: Veterinarians were available to provide advice on animal management and care throughout the study. If medication was required for sick animals, the veterinarian would provide a treatment recommendation, which would be implemented only after approval by the SD (Student Management Office). No veterinary treatment was provided during the entire study.

[0097] 2 Experimental Design 2.1 Random Grouping This study selected 15 healthy male animals and randomly divided them into 5 groups. Group 1 was administered baricitinib tablet suspension by gavage (fasted for approximately 12 hours before administration, and given food and free access to water 1 hour after administration). Groups 2-5 were administered the compounds listed in Table 8 via intramuscular injection (all prepared using a solution dissolved in 1 ml of sesame oil and benzyl benzoate (3:2)). The specific administration regimens are shown in Table 8 below: Table 8 Dosing Regimen

[0098] △ All values ​​are calculated based on baricitinib, YPK-037. Taking this invention as an example, 210mg / mL×0.668=140.28mg / mL (conversion factor: 371.42 / 555.7=0.668).

[0099] 2.2 Drug administration related information Route of administration: intramuscular injection (hamstring muscles) and subcutaneous injection (skin of neck and back); Frequency of administration: single dose.

[0100] 2.3 Rationale for route of administration and dosage design According to the information provided by the client, the test product is intended for intramuscular injection in clinical use, therefore intramuscular injection was chosen. For baricitinib tablets, oral administration was chosen, and gavage was selected. In clinical use, the recommended dose of baricitinib tablets for alopecia areata is 4 mg once daily (total dose 4 mg / person), which is approximately 0.067 mg / kg in rats based on a daily dose of 4 mg / 60 kg. Based on the maximum allowable intramuscular injection volume in rats, the maximum intramuscular dose of YPK-037 is calculated to be 210 mg / kg (equivalent to 4 mg / kg for baricitinib). Therefore, the dose in this experiment was appropriately increased from the human daily dose converted to a rat dose of 4 mg / kg to investigate relative bioavailability.

[0101] 3. Animal observation, blood sample collection and biological sample analysis 3.1 Clinical observation No obvious abnormalities were observed after administration.

[0102] 3.2 Sample Collection Collection method: Blood is collected from the submandibular vein, approximately 0.15 mL each time.

[0103] Data collection time points: 0h before administration, 15 min, 30 min, 1h, 2h, 4h, 8h, 12h, 24h (1 day), 48h (2 days), 72h (3 days), 168h (7 days), 336h (14 days), 504h (21 days), and 672h (28 days) after administration for each group.

[0104] 3.3 Sample Separation and Preservation Sampling requirements and processing: Blood was collected using EDTA-K2 anticoagulant tubes. After collection, the blood was centrifuged at 1500g for 15 minutes under yellow light, followed by plasma separation. The samples were temporarily frozen at approximately -20℃, and then transferred to the sample room refrigerator for further analysis.

[0105] 3.4 Biological Sample Analysis After sampling, the concentration of baricitinib in the samples was determined using LC-MS / MS.

[0106] 3.5 Data Processing and Statistical Analysis Data processing of measurement results: The concentration results of all samples were acquired and processed by the analytical instrument itself; pharmacokinetic parameters were calculated using WinNonlin. BLQ samples before reaching Cmax were calculated as zero values, while samples after reaching Cmax were left blank for calculation. After WinNonlin calculation, concentrations and parameters are expressed to three significant figures, and ratios and percentages of parameters are retained to two decimal places. Values ​​in some tables may differ slightly from individually calculated results, but the completeness and continuity of the data are not affected.

[0107] 3.6 Results and Evaluation The pharmacokinetic curves were obtained based on the concentration data at each time point. The pharmacokinetic parameters AUC0-t, Cmax, Tmax, and T1 / 2 were calculated using the non-compartmental model module of Phoenix WinNonlin software, and the pharmacokinetic differences among the groups were compared.

[0108] 4 Results The plasma concentrations of the original drug baricitinib in groups 1-5, administered by gavage and intramuscular injection respectively, are detailed in Table 9. As shown in Table 9, the compounds of this invention can be slowly, continuously, and stably released and converted into baricitinib in vivo, thus exerting a long-acting effect. The results indicate that this invention achieves a long-acting release effect.

[0109] Table 9. Blood drug concentrations in rats after administration

[0110] Test Example 5: Local Security Evaluation 1. In vitro tube hemolytic test 1.1 Test Methods Unless otherwise specified, for injectable preparations intended for non-intravascular administration, the test solution shall be prepared by diluting the clinically used concentration specified in the drug's instructions for use with 0.9% sodium chloride solution at a ratio of 1:3. For injectable preparations intended for intravascular administration, the clinically used concentration of the test substance shall be used as the concentration of the test solution.

[0111] 1.2 Preparation of test sample 1.2.1 Preparation of Red Blood Cell Suspension: 9.8 mL of blood was collected from the heart of a New Zealand rabbit and placed in a beaker. The blood was stirred in the same direction with a fine glass rod to remove fibrinogen, and then transferred to a centrifuge tube. Approximately 10 times the volume of sodium chloride injection solution was added and mixed thoroughly. The mixture was centrifuged at 1500 rpm for 15 min, and the supernatant was removed. The precipitated red blood cells were washed three times with sodium chloride injection solution as described above until the supernatant was colorless and transparent. Finally, the obtained red blood cells were diluted with sodium chloride injection solution at a volume ratio to prepare a 2% red blood cell suspension.

[0112] 1.2.2 Test Number and Method Table 10 Test Numbers and Methods

[0113] Note: All concentrations above are initially prepared as 200 mg / vial of baricitinib. Experimental preparation method (CMC-Na / polyethylene glycol 4000 / Tween 80 / water = 95 mg / 40 mg / 0.5 mg / add water to 1 ml).

[0114] First, take four test tubes and number them sequentially as Experiment 1 to 4. Add 2.5 ml of 2% red blood cell suspension to each tube. Add 2.0 ml of sodium chloride injection to tubes 1 and 2, 2.5 ml of sodium chloride injection to tube 3, and 2.5 ml of distilled water to tube 4 as a positive control. Add 0.5 ml of 0.5 mg / mL baricitinib injection and the solution prepared according to this invention to tubes 1 and 2, respectively, as detailed in Table 10. Incubate in a water bath at 37℃±0.5℃. Observe every 15 minutes initially, then every hour thereafter, for a total of 3 hours. Visually inspect each tube for hemolysis; the judgment criteria are shown in Table 11.

[0115] Table 11 Criteria for Judging Hemolysis and Agglutination of Erythrocytes

[0116] 1.3 Test Results In tube #4 (positive control), the solution turned clear red after adding distilled water in about 5 minutes, with no red blood cell precipitate at the bottom, indicating hemolysis. In tubes #1 and #2, the solution was initially cloudy after adding the test sample, without a clear red or brownish-red color, indicating no hemolysis at that stage. Over time, the red blood cells in tube #2 began to settle, and all settled after 3 hours. In tube #1, some red blood cells remained in the upper layer after 2 hours, indicating partial hemolysis. Tubes #2 and #3 showed similar phenomena, but differed significantly from tube #4. The results are shown in Table 12.

[0117] Table 12 Test Results

[0118] Note: In the table, "-" indicates no hemolysis, and "+" indicates hemolysis.

[0119] The experimental results show that the compound of the present invention does not cause hemolysis when injected, while the parent compound has the potential for hemolysis due to baricitinib injection.

[0120] 2. Stimulation test 1) Muscle stimulation test Healthy female SD rats, weighing 300–350 g, were selected and allowed free access to food and water during the experiment. Following a bilateral comparison method, 0.2 mL (approximately 30 times the dose recommended by the European Medicines Agency) of baricitinib injection and the injection formulation of this invention (dilution method and concentration as in the in vitro hemolysis test, 0.5 mg / mL) were injected intramuscularly into the quadriceps femoris muscle of the left hind limb of the rats. The same volume of 0.9% saline was injected intramuscularly into the quadriceps femoris muscle of the right hind limb as a control. The stimulation response scores of the quadriceps femoris muscle were evaluated according to Table 13. The stimulation response scores of the baricitinib injection group, the injection formulation of this invention group, and the 0.9% saline injection group were added together to obtain their respective total scores. The final score was obtained by dividing the total score by the number of rats, and the stimulation level was determined according to Table 14. If necessary, oily muscle tissue was collected, fixed in 4% paraformaldehyde solution, and sent to a third-party company for section preparation and pathological examination such as HE staining.

[0121] Table 13 Criteria for Determining the Grade of Muscle Stimulation Response

[0122] Table 14 Average scores and levels of muscle stimulation

[0123] Post-mortem results: 48 hours after administration, the quadriceps femoris muscle injected with 0.9% saline and the quadriceps femoris muscle injected with the injection of the present invention were both rosy in color, elastic to the touch, and showed no obvious abnormalities. However, the muscle at the site of baricitinib injection showed redness and congestion, with a diameter of about 1 cm, and mild irritation.

[0124] 2) Subcutaneous tissue irritation test Healthy female SD rats, weighing 300–350 g, were selected and allowed free access to food and water during the experiment. Following a bilateral comparison method, rats were placed in a prone position and injected subcutaneously into the left side of the neck with 0.2 mL (approximately 30 times the dose recommended by the European Medicines Agency) of baricitinib injection and the injectable formulation of this invention (dilution method and concentration as in the in vitro hemolysis test, 0.5 mg / mL). The same volume of 0.9% saline was injected subcutaneously into the right side of the neck as a control. The inflammatory response at the subcutaneous injection site was scored according to the skin irritation response evaluation criteria. The irritation response scores of the baricitinib injection and injectable formulation groups and the 0.9% saline injection group were added together to obtain their respective total scores. The final score was obtained by dividing the total score by the number of rats. The irritant intensity of the subcutaneous injection was evaluated according to the skin irritation intensity standard. If necessary, subcutaneous tissue encapsulated with gel was taken, fixed in 4% paraformaldehyde solution, and sent to a third-party company for section preparation and pathological examination such as HE staining.

[0125] The experimental results showed that, 48 hours after a single subcutaneous injection of baricitinib injection or the injection prepared according to this invention into the neck of the experimental rats, no obvious pathological changes were observed in the subcutaneous tissue of the neck. According to the evaluation criteria, neither caused any irritation to the subcutaneous tissue.

[0126] Test Example 6: Experimental Study on In Vitro Cytotoxicity of Normal Human Hepatocytes 1. Experimental Materials 1.1 Cells: LO2 cells, a human hepatitis cell line 1.2 Drug: The compound of this invention has an HPLC purity of 99.9%. 1.3 Reagents and Instruments: Modified RPMI-1640 culture medium, penicillin-streptomycin solution, 0.25% trypsin-EDTA, fetal bovine serum, MTT, dimethyl sulfoxide, CO-150 carbon monoxide incubator, SW-CJ-2F medical clean bench, CKX-41-32 inverted microscope, CU600 electric thermostatic water bath, RT-2100C enzyme-linked immunosorbent assay (ELISA) analyzer. 2 Experimental Methods 2.1 Reagent Preparation 2.1.1 Preparation of MTT: Weigh 0.25g of MTT using a precision balance and place it in a 50mL volumetric flask. Add an appropriate amount of PBS, incubate in a 50-60℃ water bath, and shake well to dissolve completely. Add PBS to the mark to prepare a 6.5mg / kg solution. Filter the solution through a 0.22μm microporous membrane for sterilization, aliquot, and store in a refrigerator at 4℃ protected from light.

[0127] 2.1.2 Preparation of cell cryopreservation solution: Mix 20% serum, 10% DMSO and 70% 1640 medium evenly and store at -20℃.

[0128] 2.1.3 The compounds of the present invention are prepared by using DMSO to prepare a stock solution of the drug, and then diluting it with culture medium to the concentration of the drug to be used. The final concentration of DMSO is controlled to be ≤0.1%.

[0129] 2.2 LO2 cell culture: Normal human LO2 cells were placed in a 25cm² culture medium. 2 Add approximately 4–5 mL of RPMI-1640 culture medium containing 10% FBS to cell culture flasks and incubate at 37°C in a 5% CO2 saturated humidity cell culture incubator. Change the culture medium every 2 days and observe cell growth daily. Once cells reach 80% confluence, passage or cryopreserve them. Use cells from passages 5–7 for formal experiments.

[0130] 2.3 Grouping and drug administration experiments were conducted by dividing the experiment into a normal cell control group and drug administration groups with different concentrations of the present invention, based on the preliminary experimental results. The concentrations were 13.5, 135, 270, 675, 1350 and 6750 μmol / L, respectively.

[0131] 2.4 Hepatocyte MTT assay: Logarithmic growth phase LO2 cells were prepared into a cell suspension of 5.0 × 10³ cells / mL and seeded into 96-well plates. A normal control group and different concentrations (13.5, 135, 270, 675, 1350, and 6750 μmol / L) of the compound of the present invention were set up. After 24 h of culture, the culture medium was aspirated, and the cells were washed 2–3 times with PBS. Different concentrations of the compound of the present invention were added, with 8 replicates per concentration. The plates were incubated at 37°C in a 5% CO₂ incubator. After 24, 48, and 72 h of culture, MTT solution was added at each time point, and the plates were incubated in the dark for 4 h. After 4 h, the supernatant was aspirated, and 150 L DMSO was added to each well to dissolve the thiazolyl blue crystals. The plates were gently shaken to ensure uniform dissolution. The absorbance of each well was measured at 490 nm using a microplate reader. The absorbance value of each well directly reflects the number of cells. The experiment was repeated three times. Cell viability was calculated as follows: Cell viability (%) = Absorbance of each group (OD490) × 100 / Absorbance of the control group (OD490) 2.5 Statistical Analysis All data are expressed as mean ± standard deviation and were processed using SPSS 17.0 statistical software. t-tests were performed for statistical analysis; paired t-tests were used for self-comparisons, and unpaired t-tests were used for inter-group comparisons. The significance level was P < 0.05.

[0132] 3 Experimental Results Table 15 Experimental Results

[0133] Conclusion: After 72 h of administration, the OD values ​​of cells in each group showed an increasing trend at different concentrations of the present invention, but the growth rate decreased, indicating that the cells were still in the growth stage and the growth rate was somewhat inhibited. Different concentrations of the present invention had no inhibitory effect on cells; compared with the normal group, the cell survival rate was greater than 90%. Within the range of 13.5, 135, 270, 675, 1350, and 6750 μmol / L, it showed almost no inhibition of cell growth and no cytotoxicity.

[0134] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. The compound represented by Formula I or its salt: 。 2. The crystal of the compound of formula I as described in claim 1, characterized in that, The X-ray powder diffraction of the crystal, expressed as a diffraction angle of 2θ±0.2°, has the following characteristic peaks: 19.56±0.2°, 19.58±0.2°, 19.60±0.2°, 19.62±0.2°, 19.64±0.2°, 19.68±0.2°, 19.74±0.2°, 19.76±0.2°, 19.80±0.2°, 19.92±0.2°, and 20.02±0.2°.

3. The crystal of the compound of formula I according to claim 2, characterized in that, The X-ray powder diffraction pattern of the crystal is shown in Figure 1.

4. The crystal of the compound of formula I as described in claim 1, characterized in that, The DSC curve of the crystal shows that the onset temperature of the endothermic peak is 94.745±2℃ and the peak temperature is 100.69±2℃.

5. A pharmaceutical composition comprising a compound of formula I as claimed in claim 1 or a salt thereof and a pharmaceutically acceptable carrier.

6. The pharmaceutical composition of claim 5, formulated for intramuscular, intradermal, or subcutaneous injection.

7. The pharmaceutical composition of claim 6, wherein the dosage form is a suspension injection or an oil injection.

8. The use of the compound of claim 1 or a salt thereof, or a pharmaceutical composition of claim 5, in the preparation of a medicament for treating autoimmune diseases, inflammatory diseases, or cancer diseases involving JAK.

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