Boron tribromide → 3-Nitro-5-(5-(2-(trifluoromethyl)pyridin-3-yl)-1,2,3-thiadiazol-4-yl)benzene-1,2-diol

4-(3,4-bis(benzyloxy)-5-nitrophenyl)-5-(2-(trifluoromethyl)pyridin-3-yl)-1,2,3-thiadiazole (0.147 g, 0.26 mmol) in dichloromethane (10 mL) was cooled to −78° C. with stirring and treated under argon with boron tribromide (0.26 g, 1.03 mmol). The resulting deep purple suspension was then allowed to stir at room temperature for one hour before cooling again to −40° C. The mixture was quenched by the careful addition of methanol. After stifling at room temperature for thirty minutes, the volatiles were evaporated and the residue stirred with 2 N hydrochloric acid (5 mL) for thirty minutes. The resulting solid was filtered off, washed with water (25 mL) and then cold isopropanol (5 mL) to give 3-nitro-5-(5-(2-(trifluoromethyl)pyridin-3-yl)-1,2,3-thiadiazol-4-yl)benzene-1,2-diol as a yellow solid, 0.089 g (89%).

1. stirringto stir at room temperature for one hour
2. customThe mixture was quenched by the careful addition of methanol
3. waitAfter stifling at room temperature for thirty minutes
4. customthe volatiles were evaporated
5. stirringthe residue stirred with 2 N hydrochloric acid (5 mL) for thirty minutes
6. filtrationThe resulting solid was filtered off
7. washwashed with water (25 mL)

ORD record

ord-a189a081a0ee4a2591bdf25658cd0d19

Source dataset

uspto-grants-2016_09

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US09446012B2