m-Chloroperbenzoic acid → HCID 118114730, compound

Participants

Reaction Steps

To ethyl 5-chloro-3-(methylthio)-1,2,4-triazine-6-carboxylate (1) (1.20 g, 5.15 mmol) in acetonitrile (40 mL) was added tert-butyl 4-(4-aminophenyl)piperidine-1-carboxylate (2.14 g, 7.73 mmol) and then DIEA (1350 μL, 7.73 mmol). The mixture was stirred at RT for 1 hour. To the mixture was then added ammonia (7.0 N solution in methanol, 30 mL). The mixture turned cloudy in 10 min and then into a suspension. The mixture was stirred for 8 hours, and the solid was isolated by filtration. It was washed with cold acetonitrile (10 mL×2) and then washed with hexane (10 mL×3). The solid was dried in a vacuum oven to afford tert-butyl 4-(4-(6-carbamoyl-3-(methylthio)-1,2,4-triazin-5-ylamino)phenyl)piperidine-1-carboxylate (490) (1.82 g, 79% yield) in high purity. Compound 490 (600 mg, 1.35 mmol) was dissolved in 20 mL NMP. To it were added dry mCPBA (77% strength, 840 mg, 3.38 mmol). The mixture was stirred at RT for 1 hour. To the mixture was added DIEA (2.10 mL, 12.1 mmol) and (R)-4-methoxy-N-(piperidin-3-yl)benzamide hydrochloride (489) (550 mg, 2.03 mmol). The mixture was stirred at 70° C. for 30 min. The mixture was cooled to RT, diluted with 200 mL chloroform, washed with 1N NaOH (aq) ×2 and water, dried, concentrated in vacuo to dryness for crude (R)-tert-butyl 4-(4-(6-carbamoyl-3-(3-(4-methoxybenzamido)piperidin-1-yl)-1,2,4-triazin-5-ylamino)phenyl)piperidine-1-carboxylate (491) (740 mg, 87%). It was treated with 35 mL commercial 4N HCl in dioxane at RT for 45 min. The mixture was concentrated in vacuo to dryness to afford crude (R)-3-(3-(4-methoxybenzamido)piperidin-1-yl)-5-(4-(piperidin-4-yl)phenylamino)-1,2,4-triazine-6-carboxamide (492). A small amount of crude 492 was purified using reverse phase prep HPLC to isolate as HCl salt. LC-MS (ESI): m/z (M+1) 531.1. UV: λ=255 nm.

Provenance & Evidence