Ammonium Hydroxide → N-(3-((4aS,5S,7aS)-2-amino-5-(trifluoromethyl)-4a,5,7,7a-tetrahydro-4H-furo[3,4-d][1,3]thiazin-7a-yl)-4-fluorophenyl)-5-(fluoromethyl)pyrazine-2-carboxamide

Participants

Reaction Conditions

Reaction Steps

5-(Fluoromethyl)pyrazine-2-carboxylic acid (32.6 g, 1.05 equiv) and (4aS,5S,7aS)-7a-(5-amino-2-fluorophenyl)-5-(trifluoromethyl)-4a,5,7,7a-tetrahydro-4H-furo[3,4-d][1,3]thiazin-2-amine (70.0 g, 1.0 equiv) were charged to a reactor and EtOAc (630 mL) was added to the mixture to give a suspension. A solution of ®T3P (146 g, 1.10 equiv, 50 wt % in EtOAc) (Archimica, Germany) was added at ambient temperature while controlling the internal temperature below 30° C. The reaction mixture was stirred at 40-45° C.>3 hours and monitored by HPLC. The reaction mixture was cooled to 15-20° C. and water (140 mL) was charged. After 10-15 minutes charged 28% ammonium hydroxide (175 mL) while controlling the temperature below 30° C. EtOAc (245 mL0 was added and the reaction mixture was stirred for 30 minutes at ambient temperature. The aqueous phase was separated and back-extracted with EtOAc (490 mL). The organic phases were combined and washed with 15% aq. NaCl (140 mL) and water (140 mL). The organic layer was filtered over Celite (1.0 Wt) and rinsed with EtOAc (140 mL). The solution was concentrated under vacuum to obtain a beige solid (quantitative crude yield) which was recrystallized from 1-propanol to afford N-(3-((4aS,5S,7aS)-2-amino-5-(trifluoromethyl)-4a,5,7,7a-tetrahydro-4H-furo[3,4-d][1,3]thiazin-7a-yl)-4-fluorophenyl)-5-(fluoromethyl)pyrazine-2-carboxamide as a white solid (70.0 g).

Provenance & Evidence