Reaktion #48033

Reaktionsgleichung

4-chloroaniline

NaNO2

NaOAc

ethyl 2-chloro-3-oxobutanoate

→

ethyl 2-chloro[(4-chlorophenyl)hydrazono]acetate

Ausbeute 73.4%

Lösungsmittel

—

ice

hydrochloric acid

water

ethanol

Reaktionsbedingungen

Aufarbeitung

1. 1
   workup.STIRRINGAfter stirring the resulting mixture for 1 hour the formed precipitate
2. 2
   Filtrationis collected by filtration
3. 3
   Waschenwashed with ethanol
4. 4
   Sonstigedried in vacuo

Vorschrift

Part A: To a stirred solution of 4-chloroaniline (15.68 gram, 0.123 mol) in ice (30 ml) and concentrated hydrochloric acid (30 ml) is slowly added a solution of NaNO2 (9.0 gram, 0.13 mol) in water (16 ml) and the resulting solution is stirred for 1Hour at 0-5° C. and subsequently added to a cold mixture of NaOAc (32 gram, 0.39 mol), ethanol (520 ml) and ethyl 2-chloro-3-oxobutanoate (16.6 ml, 0.12 mol). After stirring the resulting mixture for 1 hour the formed precipitate is collected by filtration, washed with ethanol and dried in vacuo to give ethyl 2-chloro[(4-chlorophenyl)hydrazono]acetate (22.99 gram, 73% yield). Melting point: 147.5-149.5° C. 1H-NMR (200 MHz, CDCl3): 1.40 (t, J=7 Hz, 3H), 4.39 (q, J=7 Hz, 2H), 7.16 (br d, J=8 Hz, 2H), 7.30 (br d, J=8 Hz, 2H), 8.31 (br s, 1H).

Quelle