Reaktion #76766

Reaktionsgleichung

ethyl 5-amino-2-chloro-4-fluorobenzoate

sodium nitrite

tin(II)chloride

→

ethyl 2-chloro-4-fluoro-5-hydrazinobenzoate hydrochloride

Ausbeute 116.0%

Lösungsmittel

hydrochloric acid

hydrochloric acid

water

Reaktionsbedingungen

Aufarbeitung

1. 1
   workup.ADDITIONwas added dropwise at 10° C.
2. 2
   workup.ADDITIONwas poured
3. 3
   workup.STIRRINGby further stirring at 0° C. for 3 hours
4. 4
   FiltrationThe precipitated crystals were collected by filtration
5. 5
   Sonstigedried

Vorschrift

Then, 19 g (87.4 mmol) of ethyl 5-amino-2-chloro-4-fluorobenzoate was dissolved in 120 ml of hydrochloric acid, followed by cooling to 0° C., to which a solution of 6.3 g (91.7 mmol) of sodium nitrite dissolved in 10 ml of water was added dropwise at 10° C. or lower. The mixture was stirred at 0° C. for 30 minutes and then cooled to −30° C., into which a solution of 58 g (0.31 mol) of anhydrous tin(II)chloride dissolved in 40 ml of hydrochloric acid was poured, followed by further stirring at 0° C. for 3 hours. The precipitated crystals were collected by filtration and then dried, which afforded 13.6 g (50.7 mmol) of crude ethyl 2-chloro-4-fluoro-5-hydrazinobenzoate hydrochloride.

Quelle