Reaktion #2286298

Reaktionsgleichung

sodium acetate

[3,5-dibromo-4-(6-chloro-5-isopropyl-pyridazin-3-yloxy)-phenyl]-proprionic acid

3-[3,5-Dibromo-4-(6-chloro-5-isopropyl-pyridazin-3-yloxy)-phenyl]-propionic acid

→

[3,5-dibromo-4-(5-isopropyl-6-oxo-1,6-dihydro-pyridazin-3-yloxy)-phenyl]-proprionic acid

Ausbeute 72.0%

3-[3,5-Dibromo-4-(5-isopropyl-6-oxo-1,6-dihydro-pyridazin-3-yloxy)-phenyl]-propionic acid

Ausbeute 72.0%

Lösungsmittel

acetic acid

Reaktionsbedingungen

Aufarbeitung

1. 1
   TemperaturThe reaction mixture was cooled to room temperature
2. 2
   Einengenconcentrated
3. 3
   workup.ADDITIONThe resulting residue was diluted with water (200 mL)
4. 4
   workup.ADDITIONwas made basic to pH=9 by the addition of a 1N aqueous sodium hydroxide solution
5. 5
   ExtraktionThis solution was extracted with ethyl acetate (1×100 mL)
6. 6
   workup.ADDITIONThe water layer was acidified to pH=3 by the addition of a 1N aqueous hydrochloric acid solution
7. 7
   ExtraktionThe water layer was extracted with ethyl acetate (3×100 mL)
8. 8
   Trocknendried with sodium sulfate
9. 9
   Filtrationfiltered
10. 10
    Einengenconcentrated under vacuum
11. 11
    workup.ADDITIONHeptane (20 mL) was added to this mixture
12. 12
    EinengenThe solvents were then concentrated under vacuum to a volume of approximately 20 mL
13. 13
    FiltrationThe solids were filtered
14. 14
    Waschenwashed with a 1:1 ethyl acetate
15. 15
    SonstigeThe solid was dried under high vacuum

Vorschrift

A mixture of glacial acetic acid (16.7 mL), sodium acetate (480 mg, 5.85 mmol) and [3,5-dibromo-4-(6-chloro-5-isopropyl-pyridazin-3-yloxy)-phenyl]-proprionic acid (22) (800 mg, 1.67 mmol) was heated to 120° C. for 24 h. The reaction mixture was cooled to room temperature and concentrated. The resulting residue was diluted with water (200 mL) and was made basic to pH=9 by the addition of a 1N aqueous sodium hydroxide solution. This solution was extracted with ethyl acetate (1×100 mL) and the ethyl acetate was discarded. The water layer was acidified to pH=3 by the addition of a 1N aqueous hydrochloric acid solution. The water layer was extracted with ethyl acetate (3×100 mL). The organic layers were combined, dried with sodium sulfate, filtered and concentrated under vacuum. The resulting solid was slurried in ethyl acetate (20 mL). Heptane (20 mL) was added to this mixture. The solvents were then concentrated under vacuum to a volume of approximately 20 mL. The solids were filtered and washed with a 1:1 ethyl acetate:heptane solution (2×10 mL). The solid was dried under high vacuum to afford [3,5-dibromo-4-(5-isopropyl-6-oxo-1,6-dihydro-pyridazin-3-yloxy)-phenyl]-proprionic acid (23) (553 mg, 72%) as an off-white solid; LRMS for C16H16Br2N2O4 (M+H) m/z=461. Molecular Weight=460.1249; Exact Mass=457.9477

Quelle