Reaction #2329055

Reaction equation

HCl

4-bromo-2-(2H-[1,2,4]triazol-3-yl)-phenylamine

chloroacetyl chloride

NaOH

→

title compound

Yield 46.0%

9-Bromo-6H-1,3,3a,6-tetraaza-benzo[e]azulen-5-one

Yield 46.0%

Solvents

dioxane

pyridine

diethylether

Conditions

Workup

1. 1
   workup.STIRRINGThe mixture was stirred for 17.5 h at ambient temperature
2. 2
   workup.ADDITIONThe pH thereby dropped to about pH=9 and it
3. 3
   OtherAfter evaporation the residue
4. 4
   workup.STIRRINGwas stirred at 15° C. for 30 min in water (650 mL)
5. 5
   FiltrationThe crystals were filtered off
6. 6
   Washwashed with cold water
7. 7
   Otherdried in vacuo

Procedure

A solution of 4-bromo-2-(2H-[1,2,4]triazol-3-yl)-phenylamine (25.0 g, 105 mmol) in dioxane (870 mL) and pyridine (10.0 mL) was cooled to 12° C. A solution of chloroacetyl chloride (9.56 ml, 121 mmol) in diethylether (34.7 mL) was added dropwise over a period of 8 min. The mixture was stirred at 10° C.-12° C. for 75 min and treated within 5 min with aqueous NaOH (2 N, 126 ml, 251 mmol). The mixture was stirred for 17.5 h at ambient temperature. The pH thereby dropped to about pH=9 and it was adjusted to pH=8 with HCl (3 N, 6 mL). After evaporation the residue was stirred at 15° C. for 30 min in water (650 mL) and ethyl acetate (22 mL). The crystals were filtered off, washed with cold water and dried in vacuo. Trituration in ethyl acetate (100 mL) afforded the title compound (13.4 g, 46%) as a light yellow solid. MS: m/e=279.0/281.0 [M+H]+.

Source