Imidazopyridine acyl-KAGDV as well as synthesis, antithrombotic activity and application thereof

[0026] Example 1 Preparation of 4,5,6,7-tetrahydro-3H-imidazo[4,5-c]pyridine-6-carboxylic acid (1)

[0027] Under ice bath and stirring, slowly drop 0.8mL H into the solution of 5g (32.3mmol) L-His and 18mL water 2 SO 4 , Make it completely dissolved. Add 6 mL of 40% aqueous formaldehyde solution to this solution. The ice bath was removed, and the reaction was carried out at 60°C for 8 hours. TLC (ethyl acetate: water: glacial acetic acid = 4:1:1) monitored the disappearance of the raw material. The reaction solution was cooled to room temperature, and the pH was adjusted to 6 with concentrated ammonia water under an ice bath, and a large amount of colorless solid was precipitated. filter. The filter residue was washed with water and acetone to obtain 4.52 g (84%) of the title compound. ESI-MS(m/e): 168[M+H] +.

[0028] Example 2 Preparation of 3,5-di-Boc-4,5,6,7-tetrahydro-3H-imidazo[4,5-c]pyridine-6-carboxylic acid (2)

[0029] Add 40mL 1,4 to a solution of 5g (29.9mmol) 4,5,6,7-tetrahydro-3H-imidazo[4,5-c]pyridine-6-carboxylic acid and 40mL water under ice bath and stirring. -14.3g (65.7mmol) dissolved in dioxane (Boc) 2 O, adjust the pH to 8-9 with 4N NaOH solution, and react at room temperature for 24 hours. TLC (dichloromethane: methanol = 15:1) monitors the disappearance of the starting material. Saturated KHSO for reaction liquid 4 Adjust the pH of the solution to 7, after distilling out 1,4-dioxane under reduced pressure, use saturated KHSO 4 Adjust the pH of the solution to 2. It was extracted three times with ethyl acetate, and the ester layer was washed three times with saturated NaCl. Dry with anhydrous sodium sulfate for 30 minutes and filter. The filtrate was evaporated to dryness under reduced pressure. Add a small amount of ethyl acetate to just dissolve it and let it stand. A solid precipitated out and filtered. 1.2 g (11%) of the title compound was obtained as a colorless solid. ESI-MS(m/e): 368[M+H] +.

[0030] Example 3 Preparation of 3,5-Di-Boc-4,5,6,7-tetrahydro-3H-imidazo[4,5-c]pyridine-6-formyl-Lys(Boc)-OBzl(3)

[0031] Under an ice bath, 367mg (1mmol) of 3,5-di-Boc-4,5,6,7-tetrahydro-3H-imidazo[4,5-c]pyridine-6 ​​was mixed with 20mL of dry tetrahydrofuran (THF) -The carboxylic acid dissolves. Add 142mg (1.05mmol) HOBt and 258mg (1.25mmol) DCC, stir and activate for 30min. Dissolve 558 mg (1.1 mmol) of Tos·Lys(Boc)-OBzl with 10 mL of dry THF, adjust the pH to 8 with NMM, add the solution dropwise to the reaction solution, and finally adjust the pH of the reaction solution to 8 with NMM. After reacting at room temperature for 5 hours, TLC (petroleum ether:acetone=3:1) showed that the raw material disappeared. Dicyclohexylurea (DCU) was removed by filtration, the reaction solution was evaporated under reduced pressure, the residue was dissolved in ethyl acetate, and then saturated NaHCO 3 Solution, saturated NaCl solution, 5% KHSO 4 Solution, saturated NaCl solution, saturated NaHCO 3 Wash the solution and saturated NaCl solution three times each. Anhydrous Na for ethyl acetate layer 2 SO 4 Dry for 30 min, filter, and evaporate the filtrate under reduced pressure. The obtained yellow oil was purified by silica gel column chromatography (petroleum ether/acetone as eluent) to obtain 248 mg (36%) of the title compound as a colorless solid. ESI-MS(m/e): 686[M+H] +.