Réaction #2348109

Équation de réaction

Intermediate 3

2-(4-bromo-5-chloro-2-methoxyphenyl)-2,4-dihydro-5-(5-bromothien-2-yl)-3H-1,2,4-triazol-3-one

2-(4-Bromo-5-chloro-2-methoxyphenyl)-2,4-dihydro-5-(5-bromothien-2-yl)-3H-1,2,4-triazol-3-one

2-(4-bromo-5-chloro-2-methoxyphenyl)-2,4-dihydro-5-(5-bromothien-2-yl)-3H-1,2,4-triazol-3-one

BBr3

Intermediate 3

2-(4-bromo-5-chloro-2-methoxyphenyl)-2,4-dihydro-5-(5-bromothien-2-yl)-3H-1,2,4-triazol-3-one

dichloromethane

2-(4-bromo-5-chloro-2-methoxyphenyl)-2,4-dihydro-5-(5-bromothien-2-yl)-3H-1,2,4-triazol-3-one

→

desired product

Rendement 81.0%

2-(4-bromo-5-chloro-2-hydroxyphenyl)-2,4-dihydro-5-(5-bromothien-2-yl)-3H-1,2,4-triazol-3-one

Rendement 81.0%

Solvants

dichloromethane

Conditions de réaction

Traitement

1. 1
   workup.ADDITIONAfter the addition
2. 2
   Températurethe reaction was warmed to room temperature
3. 3
   AutreThe reaction was quenched by the addition of 5-10 mL water
4. 4
   AutreVolatile solvent was removed under vacuum
5. 5
   Filtrationthe crude product was filtered
6. 6
   Lavagewashed with water
7. 7
   TempératureThe solid was refluxed in a mixture of acetone and ethanol for 15 minutes
8. 8
   TempératureAfter cooling to room temperature
9. 9
   Filtrationthe purified product was filtered
10. 10
    Lavagewashed with acetone and ethanol
11. 11
    AutreThe solid was dried under high vacuum

Mode opératoire

2-(4-Bromo-5-chloro-2-methoxyphenyl)-2,4-dihydro-5-(5-bromothien-2-yl)-3H-1,2,4-triazol-3-one (Intermediate 3) (1.395 g) was suspended in anhydrous dichloromethane (20-25 mL/mmol of Intermediate 3) under argon and cooled to −78° C. A 1 M solution of BBr3 (9 mL) in anhydrous dichloromethane was added via a dropping funnel over a 45 minute period. After the addition was complete, the reaction was warmed to room temperature and stirred for 5 hours. The reaction was quenched by the addition of 5-10 mL water. Volatile solvent was removed under vacuum and the crude product was filtered and washed with water. The solid was refluxed in a mixture of acetone and ethanol for 15 minutes. After cooling to room temperature, the purified product was filtered and washed with acetone and ethanol. The solid was dried under high vacuum to yield 1.1 g (81%) of the desired product, Compound II.

Source