A 1-amide-1,2-dihydrophthalazine compound, a preparation method and application thereof

Abstract

The application discloses a 1-amide-1,2-dihydrophthalazine compound and a preparation method and application thereof. The 1-amide-1,2-dihydrophthalazine compound has a chemical structure of formula (1): wherein the substituent R 1 represents an aromatic group or an alkyl group; R 2 represents an aromatic group or an alkyl group; the technical route for preparing the 1-amide-1,2-dihydrophthalazine compound is simple in operation, simple in route, high in yield, and uses common reagents, and is suitable for large-scale preparation. The compound can be applied to preparation of a staphylococcus aureus growth inhibitor, can inhibit growth of the staphylococcus aureus, and can provide a basis for research of a novel antibacterial drug.

Description

Technical Field

[0001] This invention relates to the field of chemical synthesis technology, specifically to a 1-amide-1,2-dihydrophthalazine compound, its preparation method, and its application. Background Technology

[0002] Phthalatine, as an important nitrogen-containing heterocyclic skeleton, has received widespread attention from the medicinal chemistry community over the past two decades. Extensive research into its chemical properties has shown that introducing structural diversity can enhance its effectiveness in various biological activities, such as antibacterial, anticancer, antiepileptic, antihypertensive, cardiotonic, antidiabetic, analgesic, antipsychotic, antithrombotic, vasodilatory, anti-inflammatory, antitrypanosomiasis, antileishmaniasis, asthma, and chronic obstructive pulmonary disease.

[0003] Currently, many commercially available drugs and potential drug candidates in therapeutic areas use phthalazides as their core chemical skeleton. Examples include the antihypertensive drug hydralazine, the antihistamine azassamine, and the vascular endothelial growth factor receptor (VEGFR) inhibitor vataranib. Given the wide range of applications and pharmacological activities of the phthalazide skeleton, structural modification could potentially expand the scope and intensity of its pharmacological activity, leading to the discovery of new drugs with higher efficacy and fewer side effects. Phthalatine derivatives, as important active molecules, can be synthesized in diverse ways through metal-catalyzed cyclization, coupling, or addition reactions. However, existing synthetic routes suffer from problems such as the difficulty in obtaining the necessary starting materials and metal catalysts, and low yields. Summary of the Invention

[0004] To address the aforementioned technical problems, this invention provides a 1-amide-1,2-dihydrophthalazine compound, its preparation method, and its application. This compound can inhibit the growth of Staphylococcus aureus, and its synthesis reaction conditions are simple, with a high yield, allowing for large-scale preparation.

[0005] To solve the above-mentioned technical problems, the present invention provides a technical solution as follows: a 1-amide-1,2-dihydrophthalazine compound, characterized in that it has the chemical structure of formula (1):

[0006]

[0007] Among them, substituent R 1 Represents aromatic group and alkyl group; R 2 Represents aryl and alkyl groups.

[0008] Furthermore, the substituent R 1Represents phenyl, methyl, ethyl, propyl, tert-butyl, benzyl, 1-chloropropyl, 1-methylethyl acetate, propoxy, isobutoxy, pentoxy, cyclopentoxy, 3,3,3-trichloropropoxy, chloromethoxy, allyloxy, benzyloxy, phenoxy, and 9-fluorenylmethoxy.

[0009] R 2 Represents tert-butyl, 4-ethylphenyl, 2,6-dimethylphenyl, cyclopentyl, benzyl, and 1-cyclohexenylethyl.

[0010] Furthermore, the 1-amide-1,2-dihydrophthalazine compounds have the following structures 1a-1x:

[0011]

[0012] To solve the above-mentioned technical problems, another technical solution provided by the present invention is: according to the above-described method for preparing a 1-amide-1,2-dihydrophthalazine compound, characterized by the following reaction route:

[0013]

[0014] Among them, substituent R 1 Represents aromatic group and alkyl group; R 2 Represents aryl and alkyl groups.

[0015] Furthermore, phthalazine, an acyl chloride, and an isocyanate were dissolved in an organic solvent at room temperature and reacted at -2°C to 0°C for 3-5 hours. The reaction was quenched with sodium bicarbonate, extracted with dichloromethane, dried over anhydrous sodium sulfate, concentrated, and purified to obtain 1-amide-1,2-dihydrophthalazine compounds 1a-1x.

[0016] Furthermore, the acyl chloride refers to benzoyl chloride, acetyl chloride, propionyl chloride, butyryl chloride, tert-butyryl chloride, phenylacetyl chloride, 4-chlorobutyryl chloride, 2-acetoxyisobutyryl chloride, propyl chloroformate, isobutyl chloroformate, pentyl chloroformate, cyclopentyl chloroformate, 2,2,2-trichloroethyl chloroformate, chloromethyl chloroformate, allyl chloroformate, benzyl chloroformate, phenyl chloroformate, and 9-fluorenyl chloroformate.

[0017] The isocyanates refer to tert-butylisocyanate, 4-ethylphenylisocyanate, 2,6-dimethylphenylisocyanate, cyclohexylisocyanate, phenethylisocyanate, 1-(2-isocyanoethyl)cyclohex-1-ene, and isonitrile methyl acetate.

[0018] The organic solvents mentioned refer to dichloromethane, 1,2-dichloroethane, acetonitrile, toluene, tetrahydrofuran, and 1,4-dioxane.

[0019] To solve the above-mentioned technical problems, another technical solution provided by the present invention is: the application of a 1-amide-1,2-dihydrophthalazine compound as described above in the preparation of Staphylococcus aureus growth inhibitor.

[0020] The beneficial effects of this invention are as follows:

[0021] The technical route for preparing 1-amide-1,2-dihydrophthalazine compounds described in this application is simple to operate, concise, and yields high rates. All reagents used are commonly used, and the method is suitable for large-scale preparation. Antibacterial activity tests show that the series of 1-amide-1,2-dihydrophthalazine compounds synthesized in this invention can inhibit the growth of Staphylococcus aureus. This method allows for the introduction of multiple functional groups into the entire skeleton, providing a new skeleton for the discovery of antibacterial drugs. These compounds can be used as lead compounds for subsequent development and research, and have broad application prospects.

[0022] To make the above and other objects, features and advantages of the present invention more apparent and understandable, preferred embodiments are described below in detail with reference to the accompanying drawings. Attached Figure Description

[0023] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only one of the drawings in this invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0024] Figure 1 The image shows the antibacterial activity test results of some 1-amide-1,2-dihydrophthalazine compounds. Detailed Implementation

[0025] Embodiments of the present invention will now be described in detail with reference to the accompanying drawings. While some embodiments of the invention are shown in the drawings, it should be understood that the invention can be implemented in various forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided to provide a more thorough and complete understanding of the invention. It should be understood that the accompanying drawings and embodiments are for illustrative purposes only and are not intended to limit the scope of protection of the invention.

[0026] Example

[0027] The 1-amide-1,2-dihydrophthalazine compound as described in formula (1) was prepared according to the following reaction route.

[0028]

[0029] Among them, substituent R 1Represents aromatic group and alkyl group; R 2 Represents aryl and alkyl groups.

[0030] The specific steps are as follows: phthalazine, an acyl chloride, and an isocyanate are dissolved in an organic solvent at room temperature, and reacted at -2℃ to 0℃ for 3-5 hours, preferably at 0℃ for 4 hours. The reaction is quenched with sodium bicarbonate, extracted with dichloromethane, dried with anhydrous sodium sulfate, concentrated, and purified by column chromatography to obtain 1-amide-1,2-dihydrophthalazine compounds 1a-1x.

[0031] Wherein, the acyl chloride refers to benzoyl chloride, acetyl chloride, propionyl chloride, butyryl chloride, tert-butyryl chloride, phenylacetyl chloride, 4-chlorobutyryl chloride, 2-acetoxyisobutyryl chloride, propyl chloroformate, isobutyl chloroformate, pentyl chloroformate, cyclopentyl chloroformate, 2,2,2-trichloroethyl chloroformate, chloromethyl chloroformate, allyl chloroformate, benzyl chloroformate, phenyl chloroformate, and 9-fluorenyl methyl chloroformate;

[0032] The isocyanates refer to tert-butylisocyanate, 4-ethylphenylisocyanate, 2,6-dimethylphenylisocyanate, cyclohexylisocyanate, phenethylisocyanate, 1-(2-isocyanoethyl)cyclohex-1-ene, and isonitrile methyl acetate.

[0033] The organic solvent refers to dichloromethane, 1,2-dichloroethane, acetonitrile, toluene, tetrahydrofuran, and 1,4-dioxane; the organic solvent is preferably dichloromethane or tetrahydrofuran.

[0034] The reaction route is as follows:

[0035]

[0036] Among them, substituent R 1 Represents aromatic group and alkyl group; R 2 Represents aryl and alkyl groups.

[0037] The structures of 1-amide-1,2-dihydrophthalazine compounds 1a-1x are shown below:

[0038]

[0039] The term "aromatic group" can also be called "aryl group," and should include a carbocyclic aromatic ring group with a carbon number of C6-C6. 10 Aromatic ring groups, such as phenyl (C6), fluorene (C6), etc. 10 ) group.

[0040] The synthesis of compound 1a-1x is as follows:

[0041] Synthetic compound 1a

[0042] Phthalasmine (195 mg, 1.5 mmol), benzoyl chloride (252 mg, 1.8 mmol), and tert-butyl isocyanate (150 mg, 1.8 mmol) were dissolved in dichloromethane (10 mL) and reacted at 0 °C for 4 hours. The reaction was quenched with sodium bicarbonate, extracted with dichloromethane, dried over anhydrous sodium sulfate, concentrated, and purified by column chromatography to obtain the target product 1a (428 mg, 85%). 1 H NMR (400MHz, CDCl3) δ7.74-7.69(m,2H),7.66-7.62(s,1H),7.54-7.33(m,7H),6.43(s,1H),6.23(s,1H),1.30(s,9H)ppm.

[0043] Synthetic compound 1b

[0044] Phthalasmine (195 mg, 1.5 mmol), acetyl chloride (140 mg, 1.8 mmol), and tert-butyl isocyanate (150 mg, 1.8 mmol) were dissolved in dichloromethane (10 mL) and reacted at 0 °C for 4 hours. The reaction was quenched with sodium bicarbonate, extracted with dichloromethane, dried over anhydrous sodium sulfate, concentrated, and purified by column chromatography to obtain the target product 1b (331 mg, 81%). 1 H NMR (400MHz, CDCl3) δ7.57(s,1H),7.49-7.39(m,2H),7.32-7.29(m,2H),6.12-6.05(m,2H),2.43(s,3H),1.27(s,9H)ppm.

[0045] Synthetic compound 1c

[0046] Phthalasmine (195 mg, 1.5 mmol), propionyl chloride (166 mg, 1.8 mmol), and tert-butyl isocyanate (150 mg, 1.8 mmol) were dissolved in dichloromethane (10 mL) and reacted at 0 °C for 4 hours. The reaction was quenched with sodium bicarbonate, extracted with dichloromethane, dried over anhydrous sodium sulfate, concentrated, and purified by column chromatography to obtain the target product 1c (342 mg, 80%). 1 H NMR (400MHz, CDCl3) δ7.58(s,1H),7.51-7.28(m,4H),6.17-6.00(m,2H),2.97-2.87(m,1H),2.77-2.66(m,1H),1.34-1.19(m,12H)ppm.

[0047] Synthetic compound 1d

[0048] Phthalasmine (195 mg, 1.5 mmol), butyryl chloride (191 mg, 1.8 mmol), and tert-butyl isocyanate (150 mg, 1.8 mmol) were dissolved in dichloromethane (10 mL) and reacted at 0 °C for 4 hours. The reaction was quenched with sodium bicarbonate, extracted with dichloromethane, dried over anhydrous sodium sulfate, concentrated, and purified by column chromatography to give the target product 1d (351 mg, 78%). 1 H NMR(400MHz, CDCl3)δ7.57(s,1H),7.51-7.44(m,1H),7.43-7.37(m,1H),7.33-7.27(m,2H),6.23-6.0 0(m,2H),2.96-2.85(m,1H),2.73-2.62(m,1H),1.79-1.66(m,2H),1.27(s,9H),1.05-0.98(m,3H)ppm.

[0049] Synthetic compound 1e

[0050] Phthalasmine (195 mg, 1.5 mmol), tert-butyryl chloride (216 mg, 1.8 mmol), and tert-butylisocyanate (150 mg, 1.8 mmol) were dissolved in dichloromethane (10 mL) and reacted at 0 °C for 4 hours. The reaction was quenched with sodium bicarbonate, extracted with dichloromethane, dried over anhydrous sodium sulfate, concentrated, and purified by column chromatography to give the target product 1e (338 mg, 75%). 1 H NMR (400MHz, CDCl3) δ7.56(s,1H),7.49-7.28(m,4H),6.20-5.95(m,2H),1.41(s,9H),1.26(s,9H)ppm.

[0051] Synthetic compound 1f

[0052] Phthalasmine (195 mg, 1.5 mmol), phenylacetyl chloride (277 mg, 1.8 mmol), and tert-butyl isocyanate (150 mg, 1.8 mmol) were dissolved in dichloromethane (10 mL) and reacted at 0 °C for 4 hours. The reaction was quenched with sodium bicarbonate, extracted with dichloromethane, dried over anhydrous sodium sulfate, concentrated, and purified by column chromatography to give the target product 1f (371 mg, 79%). 1 H NMR (400MHz, CDCl3) δ7.61 (s, 1H), 7.46-7.24 (m, 9H), 6.09 (s, 1H), 6.00 (s, 1H), 4.30 (d, J = 14.0Hz, 1H), 4.01 (d, J = 14.0Hz, 1H), 1.13 (s, 9H) ppm.

[0053] 1g of synthesized compound

[0054] Phthalasmine (195 mg, 1.5 mmol), 4-chlorobutyryl chloride (252 mg, 1.8 mmol), and tert-butylisocyanate (150 mg, 1.8 mmol) were dissolved in dichloromethane (10 mL) and reacted at 0 °C for 4 hours. The reaction was quenched with sodium bicarbonate, extracted with dichloromethane, dried over anhydrous sodium sulfate, concentrated, and purified by column chromatography to give 1 g (373 mg, 74%) of the target product. 1 H NMR (400MHz, CDCl3) δ7.58(s,1H),7.51-7.39(m,2H),7.35-7.29(m,2H),6.11-6.02(m,2H),3. 66(d,J=6.8Hz,2H),3.18-3.08(m,1H),2.93-2.83(m,1H),2.28-2.14(m,2H),1.27(s,9H)ppm.

[0055] Chemical synthesis of compound 1h

[0056] Phthalasmine (195 mg, 1.5 mmol), 2-acetoxyisobutyryl chloride (297 mg, 1.8 mmol), and tert-butylisocyanate (150 mg, 1.8 mmol) were dissolved in dichloromethane (10 mL) and reacted at 0 °C for 4 hours. The reaction was quenched with sodium bicarbonate, extracted with dichloromethane, dried over anhydrous sodium sulfate, concentrated, and purified by column chromatography to obtain the target product 1 h (340 mg, 63%). 1 H NMR(400MHz, CDCl3)δ9.70(s,1H),9.01-8.97(m,1H),7.87(s,1H),7.78-7.71(m ,2H),7.60-7.55(m,1H),1.98(s,3H),1.72(s,3H),1.62(s,3H),1.57(s,9H)ppm.

[0057] Synthetic compound 1i

[0058] Phthalasmine (195 mg, 1.5 mmol), propyl chloroformate (220 mg, 1.8 mmol), and tert-butyl isocyanate (150 mg, 1.8 mmol) were dissolved in dichloromethane (10 mL) and reacted at 0 °C for 4 hours. The reaction was quenched with sodium bicarbonate, extracted with dichloromethane, dried over anhydrous sodium sulfate, concentrated, and purified by column chromatography to obtain the target product 1i (376 mg, 79%). 1 H NMR(400MHz, CDCl3)δ7.66(s,1H),7.52-7.26(m,4H),5.91(s,1H),5.81(s,1 H),4.38-4.23(m,2H),1.85-1.74(m,2H),1.26(s,9H),1.05-0.92(m,3H)ppm.

[0059] Synthetic compound 1j

[0060] Phthalasmine (195 mg, 1.5 mmol), isobutyl chloroformate (247 mg, 1.8 mmol), and tert-butyl isocyanate (150 mg, 1.8 mmol) were dissolved in dichloromethane (10 mL) and reacted at 0 °C for 4 hours. The reaction was quenched with sodium bicarbonate, extracted with dichloromethane, dried over anhydrous sodium sulfate, concentrated, and purified by column chromatography to obtain the target product 1j (431 mg, 87%). 1 H NMR(400MHz, CDCl3)δ7.68(s,1H),7.51-7.28(m,4H),5.91(s,1H),5.81(s,1H), 4.13(d,J=7.2Hz,2H),2.14-2.04(m,1H),1.26(s,9H),0.99(d,J=7.2Hz,6H)ppm.

[0061] Synthetic compound 1k

[0062] Phthalasmine (195 mg, 1.5 mmol), amyl chloroformate (275 mg, 1.8 mmol), and tert-butyl isocyanate (150 mg, 1.8 mmol) were dissolved in dichloromethane (10 mL) and reacted at 0 °C for 4 hours. The reaction was quenched with sodium bicarbonate, extracted with dichloromethane, dried over anhydrous sodium sulfate, concentrated, and purified by column chromatography to obtain the target product 1K (428 mg, 83%). 1 H NMR(400MHz, CDCl3)δ7.67(s,1H),7.51-7.28(m,4H),5.94(s,1H),5.82(s,1H),4.42- 4.27(m,2H),1.84-1.72(m,2H),1.44-1.34(m,2H),1.27(s,9H),0.96-0.87(m,3H)ppm.

[0063] Synthetic compound 1l

[0064] Phthalasmine (195 mg, 1.5 mmol), cyclopentyl chloroformate (268 mg, 1.8 mmol), and tert-butyl isocyanate (150 mg, 1.8 mmol) were dissolved in dichloromethane (10 mL) and reacted at 0 °C for 4 hours. The reaction was quenched with sodium bicarbonate, extracted with dichloromethane, dried over anhydrous sodium sulfate, concentrated, and purified by column chromatography to give 1 L (449 mg, 87%) of the target product. 1H NMR(400MHz, CDCl3)δ7.67(s,1H),7.51-7.26(m,4H),5.90(s,1H),5.78(s,1H),5.3 3(s,1H),2.09-1.92(m,2H),1.90-1.74(m,4H),1.69-1.54(m,2H),1.27(s,9H)ppm.

[0065] Synthetic compound 1m

[0066] Phthalasmine (195 mg, 1.5 mmol), 2,2,2-trichloroethyl chloroformate (381 mg, 1.8 mmol), and tert-butyl isocyanate (150 mg, 1.8 mmol) were dissolved in dichloromethane (10 mL) and reacted at 0 °C for 4 hours. The reaction was quenched with sodium bicarbonate, extracted with dichloromethane, dried over anhydrous sodium sulfate, concentrated, and purified by column chromatography to give the target product 1m (492 mg, 81%). 1 H NMR (400MHz, CDCl3) δ7.77(s,1H),7.55-7.42(m,3H),7.35-7.32(m,1H),5.95-5.77(m,2H),5.10-4.91(m,2H),1.26(s,9H)ppm.

[0067] Synthetic compound 1n

[0068] Phthalasmine (195 mg, 1.5 mmol), methyl chloroformate (232 mg, 1.8 mmol), and tert-butyl isocyanate (150 mg, 1.8 mmol) were dissolved in dichloromethane (10 mL) and reacted at 0 °C for 4 hours. The reaction was quenched with sodium bicarbonate, extracted with dichloromethane, dried over anhydrous sodium sulfate, concentrated, and purified by column chromatography to obtain the target product 1n (417 mg, 86%). 1 H NMR (400MHz, CDCl3) δ7.69(s,1H),7.54-7.32(m,4H),6.07-5.86(m,3H),5.83(s,1H),1.28(s,9H)ppm.

[0069] Synthetic compound 1o

[0070] Phthalasmine (195 mg, 1.5 mmol), allyl chloroformate (217 mg, 1.8 mmol), and tert-butyl isocyanate (150 mg, 1.8 mmol) were dissolved in dichloromethane (10 mL) and reacted at 0 °C for 4 hours. The reaction was quenched with sodium bicarbonate, extracted with dichloromethane, dried over anhydrous sodium sulfate, concentrated, and purified by column chromatography to give the target product 1O (364 mg, 77%). 1H NMR (400MHz, CDCl3) δ7.68(s,1H),7.52-7.28(m,4H),6.08-5.98(m,1H),5.91(s,1H),5.82(s ,1H),5.42(d,J=17.2Hz,1H),5.30(d,J=14.4Hz,1H),4.84(d,J=6.0Hz,1H),1.27(s,9H)ppm.

[0071] Synthetic compound 1p

[0072] Phthalasmine (195 mg, 1.5 mmol), benzyl chloroformate (307 mg, 1.8 mmol), and tert-butyl isocyanate (150 mg, 1.8 mmol) were dissolved in dichloromethane (10 mL) and reacted at 0 °C for 4 hours. The reaction was quenched with sodium bicarbonate, extracted with dichloromethane, dried over anhydrous sodium sulfate, concentrated, and purified by column chromatography to give the target product 1p (447 mg, 85%). 1 H NMR (400MHz, CDCl3) δ7.67(s,1H),7.51-7.26(m,9H),6.00-5.66(m,2H),5.50-5.25(m,2H),1.19(s,9H)ppm.

[0073] Synthetic compound 1q

[0074] Phthalasmine (195 mg, 1.5 mmol), phenyl chloroformate (283 mg, 1.8 mmol), and tert-butyl isocyanate (150 mg, 1.8 mmol) were dissolved in dichloromethane (10 mL) and reacted at 0 °C for 4 hours. The reaction was quenched with sodium bicarbonate, extracted with dichloromethane, dried over anhydrous sodium sulfate, concentrated, and purified by column chromatography to obtain the target product 1q (479 mg, 91%). 1 H NMR (400MHz, CDCl3) δ7.74(s,1H),7.49-7.39(m,4H),7.36-7.19(m,5H),6.09(s,1H),5.91(s,1H),1.26(s,9H)ppm.

[0075] Synthetic compound 1r

[0076] Phthalasmine (195 mg, 1.5 mmol), fluorenyl chloroformate (466 mg, 1.8 mmol), and tert-butyl isocyanate (150 mg, 1.8 mmol) were dissolved in dichloromethane (10 mL) and reacted at 0 °C for 4 hours. The reaction was quenched with sodium bicarbonate, extracted with dichloromethane, dried over anhydrous sodium sulfate, concentrated, and purified by column chromatography to give the target product 1r (547 mg, 80%). 1H NMR (400MHz, CDCl3) δ7.79-7.68(m,5H),7.50-7.29(m,8H),6.05-5.70(m,2H ),4.67-4.60(m,1H),4.56-4.46(m,1H),4.44-4.37(m,1H),1.25(m,9H)ppm.

[0077] Synthetic compound 1s

[0078] Phthalasmine (195 mg, 1.5 mmol), 9-fluorenyl chloroformate (466 mg, 1.8 mmol), and 4-ethylphenyl isocyanate (238 mg, 1.8 mmol) were dissolved in dichloromethane (10 mL) and reacted at 0 °C for 4 hours. The reaction was quenched with sodium bicarbonate, extracted with dichloromethane, dried over anhydrous sodium sulfate, concentrated, and purified by column chromatography to give the target product 1S (555 mg, 74%). 1 H NMR (400MHz, DMSO-d6) δ10.39(s,1H),7.93-7.72(m,6H),7.57-7.28(m,9H),7.16-7. 10(m,2H),6.10(s,1H),4.53-4.33(m,3H),2.57-2.52(m,2H),1.16-1.10(m,3H)ppm.

[0079] Synthesize 1t of compound

[0080] Phthalasmine (195 mg, 1.5 mmol), 9-fluorenyl chloroformate (466 mg, 1.8 mmol), and 2,6-dimethylphenyl isocyanate (236 mg, 1.8 mmol) were dissolved in dichloromethane (10 mL) and reacted at 0 °C for 4 hours. The reaction was quenched with sodium bicarbonate, extracted with dichloromethane, dried over anhydrous sodium sulfate, concentrated, and purified by column chromatography to give 1 t (582 mg, 76%) of the target product. 1 H NMR(400MHz,DMSO-d6)δ9.78(s,1H),7.93-7.73(m,6H),7.62-7.31(m,7H),7.06- 6.97(m,3H),6.16(s,1H),4.56-4.48(m,1H),4.45-4.36(m,2H),1.96(s,6H)ppm.

[0081] Synthetic compound 1u

[0082] Phthalasmine (195 mg, 1.5 mmol), fluorenyl chloroformate (466 mg, 1.8 mmol), and cyclohexyl isocyanate (171 mg, 1.8 mmol) were dissolved in dichloromethane (10 mL) and reacted at 0 °C for 4 hours. The reaction was quenched with sodium bicarbonate, extracted with dichloromethane, dried over anhydrous sodium sulfate, concentrated, and purified by column chromatography to give 1 u (601 mg, 83%) of the target product. 1 H NMR (400MHz, CDCl3) δ7.85-7.59(m,5H),7.52-7.25(m,8H),6.20-5.62(m,2H),4.71-4.28(m,3H), 3.79-3.48(m,1H),1.82-1.69(m,2H),1.64-1.47(m,3H),1.31-1.21(m,2H),1.17-0.98(m,3H)ppm.

[0083] Synthetic compound 1v

[0084] Phthalasmine (195 mg, 1.5 mmol), fluorenyl chloroformate (466 mg, 1.8 mmol), and phenethyl isocyanate (212 mg, 1.8 mmol) were dissolved in dichloromethane (10 mL) and reacted at 0 °C for 4 hours. The reaction was quenched with sodium bicarbonate, extracted with dichloromethane, dried over anhydrous sodium sulfate, concentrated, and purified by column chromatography to give the target product 1V (425 mg, 58%). 1 H NMR (400MHz, CDCl3) δ7.78-7.63(m,5H),7.50-7.37(m,5H),7.34-7.27(m,3H),7.2 0-7.06(m,5H),6.48(s,1H),6.00(s,1H),4.60-4.44(m,2H),4.41-4.26(m,3H)ppm.

[0085] Synthetic compound 1w

[0086] Phthalasmine (195 mg, 1.5 mmol), 9-fluorenyl chloroformate (466 mg, 1.8 mmol), and 1-(2-isocyanoethyl)cyclohexyl-1-ene (243 mg, 1.8 mmol) were dissolved in dichloromethane (10 mL) and reacted at 0 °C for 4 hours. The reaction was quenched with sodium bicarbonate, extracted with dichloromethane, dried over anhydrous sodium sulfate, concentrated, and purified by column chromatography to give 1w (651 mg, 74%) of the target product. 1H NMR (400MHz, CDCl3) δ7.82-7.62(m,5H),7.53-7.28(m,8H),6.12-5.69(m,2H),5.37-5.18(s,1H),4.66-4.47(m,2H), 4.44-4.32(m,1H),3.35-3.06(m,2H),2.14-1.95(m,2H),1.94-1.86(m,2H),1.84-1.73(m,2H),1.56-1.40(m,4H)ppm.

[0087] Synthetic compound 1x

[0088] Phthalasmine (195 mg, 1.5 mmol), fluorenyl chloroformate (466 mg, 1.8 mmol), and methyl isonitrile acetate (179 mg, 1.8 mmol) were dissolved in dichloromethane (10 mL) and reacted at 0 °C for 4 hours. The reaction was quenched with sodium bicarbonate, extracted with dichloromethane, dried over anhydrous sodium sulfate, concentrated, and purified by column chromatography to give the target product 1x (583 mg, 82%). 1 H NMR (400MHz, CDCl3) δ7.84-7.63(m,5H),7.53-7.28(m,8H),6.67(m,1H),6.0 6(m,1H), 4.76-4.46(m,2H), 4.45-4.33(m,1H), 3.95(s,2H), 3.65(m,3H)ppm.

[0089] The following describes the activity tests performed on some of the compounds 1a-1x prepared in this invention:

[0090] Experimental materials

[0091] Drug preparation: 1-Amide-1,2-dihydrophthalazine compounds were prepared by the method described in the above examples. Immediately before use, a 3.2 mM stock solution was prepared with cell-grade DMSO, and then diluted with LB broth to the required concentration.

[0092] Preparation of culture medium

[0093] Preparation of solid culture medium: Weigh out a certain amount of LB agar solid powder as needed, dissolve it in distilled water, sterilize it under high temperature and high pressure conditions of 121℃ for 30 minutes, transfer it to sterile petri dishes while hot, let it cool and solidify naturally, and store it in a refrigerator at 4℃ for later use.

[0094] Preparation of liquid culture medium: Weigh out a certain amount of LB broth solid powder as needed, dissolve it in distilled water, sterilize it under high temperature and high pressure conditions at 121℃ for 30 minutes, cool it to room temperature, and store it in a refrigerator at 4℃ for later use.

[0095] Experimental methods

[0096] Strain activation: The experimental strain (Staphylococcus aureus ATCC 25923) was inoculated onto LB solid medium using the streak plate method. The medium was then inverted in a constant temperature incubator and incubated at 37°C for 24 hours.

[0097] Subculturing: Pick 3-5 morphologically identical colonies from LB solid medium with an inoculation loop and inoculate them into a shaker tube containing 4-5 mL of LB liquid medium. Place the shaker tube in a shaker at 37°C and 150 rpm to culture the bacteria to the logarithmic growth phase (6-8 h) for later use.

[0098] Bacterial suspension preparation: Prepare a bacterial suspension of 0.5 MCF using LB broth medium, containing approximately 1-5 × 10⁶ CFU / mL.

[0099] Drug dilution: In columns 2-11 of a 96-well plate, add 100 μL of LB medium to each well. Add 190 μL of LB medium to the first column of wells. Add 10 μL of drug to the first column of wells and mix thoroughly by pipetting. Perform serial dilutions, starting from the first column and proceeding sequentially to ensure a decreasing drug concentration distribution in each well. Column 11 serves as a growth control, containing only culture medium and bacterial suspension, without drug. Column 12 serves as a blank control, containing only culture medium, without bacterial suspension or drug.

[0100] Inoculation with bacteria: Add 100 μL of the prepared bacterial suspension to each well except the blank control well, so that the final bacterial count in each well is approximately 5*10⁻⁶. 5 CFU / mL

[0101] Bacterial culture: Cover the 96-well plate and incubate it in a 37°C incubator for 24 hours.

[0102] Results observation: The absorbance was measured at a wavelength of 600 nm using an ELISA reader to determine the bacterial growth. The lowest drug concentration that completely inhibits bacterial growth is the minimum inhibitory concentration (MIC).

[0103] Experimental results: See [link to results] Figure 1 The results showed that some 1-amide-1,2-dihydrophthalazine compounds inhibited the growth of Staphylococcus aureus, suggesting that this series of derivatives has potential antibacterial activity and can be used to prepare inhibitors for the growth of Staphylococcus aureus.

[0104] The description of the various embodiments above tends to emphasize the differences between the various embodiments. The similarities or similarities can be referred to each other. For the sake of brevity, this application will not repeat them.

[0105] Note that the above description is merely a preferred embodiment of the present invention and the technical principles employed. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described herein, and various obvious changes, readjustments, and substitutions can be made without departing from the scope of protection of the present invention. Therefore, although the present invention has been described in detail through the above embodiments, the present invention is not limited to the above embodiments, and may include many other equivalent embodiments without departing from the concept of the present invention, the scope of which is determined by the scope of the appended claims.

Claims

1. A 1-amide-1,2-dihydrophthalazine compound, characterized in that: It has one of the structures of compounds 1o, 1q or 1x:

2. A method for preparing the 1-amide-1,2-dihydrophthalazine compound of claim 1, characterized in that: At room temperature, phthalazine, an acyl chloride, and an isocyanate were dissolved in an organic solvent and reacted at -2°C to 0°C for 3–5 hours. The reaction was quenched with sodium bicarbonate, extracted with dichloromethane, dried over anhydrous sodium sulfate, concentrated, and purified to give 1-amide-1,2-dihydrophthalazine compounds 1o, 1q, or 1x.

3. The method for preparing a 1-amide-1,2-dihydrophthalazine compound according to claim 2, characterized in that: The acyl chloride is allyl chloroformate, and the isocyanate is tert-butylisocyanate, thus compound 1o is prepared.

4. The method for preparing a 1-amide-1,2-dihydrophthalazine compound according to claim 2, characterized in that: The acyl chloride is phenyl chloroformate, and the isocyanate is tert-butylisocyanate, thus preparing compound 1q.

5. The method for preparing a 1-amide-1,2-dihydrophthalazine compound according to claim 2, characterized in that: The acyl chloride is 9-fluorenyl chloroformate, and the isocyanate is methyl isonitrile acetate, thus preparing compound 1x.

6. A method for preparing a 1-amide-1,2-dihydrophthalazine compound according to any one of claims 2-5, characterized in that: The organic solvents mentioned refer to dichloromethane, 1,2-dichloroethane, acetonitrile, toluene, tetrahydrofuran, and 1,4-dioxane.

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