Reacción #2348109

Ecuación de reacción

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

Rendimiento 81.0%

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

Rendimiento 81.0%

Disolventes

dichloromethane

Condiciones de reacción

Tratamiento posterior

1. 1
   workup.ADDITIONAfter the addition
2. 2
   Temperaturathe reaction was warmed to room temperature
3. 3
   OtroThe reaction was quenched by the addition of 5-10 mL water
4. 4
   OtroVolatile solvent was removed under vacuum
5. 5
   Filtraciónthe crude product was filtered
6. 6
   Lavadowashed with water
7. 7
   TemperaturaThe solid was refluxed in a mixture of acetone and ethanol for 15 minutes
8. 8
   TemperaturaAfter cooling to room temperature
9. 9
   Filtraciónthe purified product was filtered
10. 10
    Lavadowashed with acetone and ethanol
11. 11
    OtroThe solid was dried under high vacuum

Procedimiento

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.

Fuente