Hydrochloric Acid → 3-Amino-1-(3-(trifluoromethyl)-5,6-dihydro(1,2,4)triazolo(4,3-a)pyrazin-7(8H)-yl)-4-(2,4,5-trifluorophenyl)butan-1-one

Participants

Reaction Conditions

Reaction Steps

In a 500 mL round bottom flask dry THF (112 mL) and NaBH4 (2.81 g) were taken. It was cooled to −15 to −10° C. After that methanesulfonic acid (17.7 g) was added dropwise at −15 to −5° C. over a period of 1.5 h. 4-oxo-4-[3-(trifluoromethyl)-5,6-dihydro[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl]-1-(2,4,5-trifluorophenyl)but-2-en-2-amine (10.0 g) was mixed in a solvent mixture of dry THF (25 mL) and IPA (11 mL) and added into the reaction mixture over a period of 45-60 min. at −10 to −5. It was stirred for 30-60 min. at −10 to −5° C. Reaction mixture was poured into cold 10% aq. HCl solution. It was basified by adding aq. NaHCO3 solution. Product was extracted in ethyl acetate. The organic layer was collected, washed with water and brine solution. It was dried over anhydrous sodium sulfate. Solvent was evaporated at reduced pressure to obtain the product. (Wt.-12.4 g, % Purity by HPLC-94.9%).

Provenance & Evidence