Ammonium Hydroxide → HCID 57827725, compound

Participants

Reaction Conditions

Reaction Steps

5-(Difluoromethyl)pyrazine-2-carboxylic acid (30.0 g, 1.05 equiv) and (4aS,5S,7aS)-7a-(5-amino-2-fluorophenyl)-5-(fluoromethyl)-4a,5,7,7a-tetrahydro-4H-furo[3,4-d][1,3]thiazin-2-amine (49.2 g, 1.00 equiv.) were charged to a reactor and EtOAc (443 mL) was added to the mixture to give a suspension. A solution of ®T3P (105 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 ambient temperature and water (98 mL) was charged. After 10-15 minutes charged 28% ammonium hydroxide (137 mL) while controlling the temperature below 30° C. Additional EtOAc (172 mL) was added and the reaction mixture was stirred for 30 minutes at ambient temperature. The aqueous phase was separated and back-extracted with EtOAc (246 mL). The organic phases were combined and washed with 15% aq. NaCl (98 mL) and water (98 mL). The organic layer was filtered over Celite (0.5 Wt) and 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-(fluoromethyl)-4a,5,7,7a-tetrahydro-4H-furo[3,4-d][1,3]thiazin-7a-yl)-4-fluorophenyl)-5-(difluoromethyl)pyrazine-2-carboxamide as a tan solid (54.2 g).

Provenance & Evidence