Novel anti-PD-L1 compound and applications thereof, and composition containing novel anti-PD-L1 compound

[0136] Example 1 Preparation of Compound I-1

[0137]

[0138] Compound I-1a (43 mg, 0.1 mmol), S-piperidine-2-carboxylic acid (13.6 mg, 0.105 mmol), and sodium triacetoxyborohydride (21.2 mg, 0.25 mmol) were added to 10 mL of dichloromethane solution The crude product was purified by preparative LC / MS with stirring at 80-85°C for 1 hour, and its purity was estimated to be 98% by LCMS analysis.

[0139] Example 2 Preparation of Compound I-14

[0140]

[0141] Compound I-14a (39 mg, 0.1 mmol), piperidine-2-carboxylic acid (13.6 mg, 0.105 mmol), and sodium triacetoxyborohydride (21.2 mg, 0.25 mmol) were added to 10 mL of dichloromethane solution, After stirring at 80-85°C for 45 minutes, the crude product was purified by preparative LC / MS and evaluated to be 97% pure by LCMS analysis.

[0142] Example 3 Preparation of compound I-20

[0143]

[0144] Compound I-20a (35 mg, 0.1 mmol), piperidine-2-carboxylic acid (13.6 mg, 0.105 mmol), and sodium triacetoxyborohydride (21.2 mg, 0.25 mmol) were added to 10 mL of dichloromethane solution, After stirring at 80-85°C for 50 minutes, the crude product was purified by preparative LC / MS and evaluated to be 98% pure by LCMS analysis.