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

HRID 62020Notes

Reaction equation

C([O:8][C:9]1[CH:10]=[C:11]([C:26]2[N:27]=[N:28][S:29][C:30]=2[C:31]2[C:32]([C:37]([F:40])([F:39])[F:38])=[N:33][CH:34]=[CH:35][CH:36]=2)[CH:12]=[C:13]([N+:23]([O-:25])=[O:24])[C:14]=1[O:15]CC1C=CC=CC=1)C1C=CC=CC=1.B(Br)(Br)Br>ClCCl>[N+:23]([C:13]1[CH:12]=[C:11]([C:26]2[N:27]=[N:28][S:29][C:30]=2[C:31]2[C:32]([C:37]([F:40])([F:39])[F:38])=[N:33][CH:34]=[CH:35][CH:36]=2)[CH:10]=[C:9]([OH:8])[C:14]=1[OH:15])([O-:25])=[O:24]

Participants

Conditions

Temperature: -40 °C

Procedure

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%).

Workup

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

Sources & evidence

ORD record: ord-a189a081a0ee4a2591bdf25658cd0d19
Source dataset: uspto-grants-2016_09
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US09446012B2

Reaction notes

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