Reaction #2286300

Reaction equation

sodium acetate

N-[3,5-dichloro-4-(6-chloro-5-isopropyl-pyridazin-3-yloxy)-phenyl]-oxalamic acid

N-[3,5-Dichloro-4-(6-chloro-5-isopropyl-pyridazin-3-yloxy)-phenyl]-oxalamic acid

→

N-[3,5-dichloro-4-(5-isopropyl-6-oxo-1,6-dihydro-pyridazin-3-yloxy)-phenyl]-oxalamic acid

Yield 56.1%

N-[3,5-Dichloro-4-(5-isopropyl-6-oxo-1,6-dihydro-pyridazin-3-yloxy)-phenyl]-oxalamic acid

Yield 56.1%

Solvents

acetic acid

Conditions

Workup

1. 1
   TemperatureThe reaction mixture was cooled to room temperature
2. 2
   Concentrationwas concentrated under vacuum
3. 3
   workup.ADDITIONThe resulting solid was diluted with water (50 mL)
4. 4
   workup.ADDITIONThe mixture was made acidic to pH=3 by the addition of glacial acetic acid
5. 5
   FiltrationThe solids were filtered
6. 6
   Washrinsed well with water
7. 7
   Otherdried on the funnel
8. 8
   Temperaturemethyl tert-butyl ether: hexanes (3 mL) and then was heated to reflux
9. 9
   TemperatureThe mixture was cooled
10. 10
    Filtrationfiltered
11. 11
    Filtrationfiltered
12. 12
    OtherThe resulting pure solid was dried under high vacuum for 24 h
13. 13
    Otherdried in a vacuum oven at 80° C. for 24 h

Procedure

A mixture of glacial acetic acid (55 mL), sodium acetate (1.2 g, 14.7 mmol) and N-[3,5-dichloro-4-(6-chloro-5-isopropyl-pyridazin-3-yloxy)-phenyl]-oxalamic acid (28) (1.7 g, 4.2 mmol) was heated to 100° C. for 24 h. The reaction mixture was cooled to room temperature and was concentrated under vacuum. The resulting solid was diluted with water (50 mL). The mixture was made acidic to pH=3 by the addition of glacial acetic acid. The solids were filtered and rinsed well with water and dried on the funnel. The solid was slurried in 1:1:2 isopropyl acetate: methyl tert-butyl ether: hexanes (3 mL) and then was heated to reflux. The mixture was cooled and filtered. A slight amount of impurity was detected by TLC. The solid was slurried in isopropyl acetate (10 mL) and filtered. The resulting pure solid was dried under high vacuum for 24 h and then dried in a vacuum oven at 80° C. for 24 h to afford N-[3,5-dichloro-4-(5-isopropyl-6-oxo-1,6-dihydro-pyridazin-3-yloxy)-phenyl]-oxalamic acid (29) (0.91 g, 56%) as a white solid; EI(+)-HRMS m/z calcd for C15H13Cl2N3O5 (M+H) 386.0305, found 386.0308. Molecular Weight=386.1940; Exact Mass=385.0232

Source