Réaction #5468

Équation de réaction

4-amino-5-chloro-2-(2-methoxyethoxy)benzoic acid methyl ester

sodium hydroxide

water

→

fine pale tan needles

Rendement 78.0%

4-Amino-5-chloro-2-(2-methoxyethoxy)benzoic acid

Rendement 78.0%

Solvants

ethanol

Conditions de réaction

Traitement

1. 1
   Températurerefluxed for one hour
2. 2
   AutreThe ethanol was removed in vacuo
3. 3
   ExtractionThe aqueous solution was extracted with ether (20 mL)
4. 4
   AutreA solid soon precipitated
5. 5
   Filtrationthis was filtered
6. 6
   Lavagewashed with water, air
7. 7
   Autredried
8. 8
   Autrerecrystallized from ethyl acetate (2 crops)

Mode opératoire

A solution of 4-amino-5-chloro-2-(2-methoxyethoxy)benzoic acid methyl ester (2.75 g, 10.6 mmol) in 95% ethanol (20 mL) was treated with 50% sodium hydroxide (10 mL) and water (10 mL), and refluxed for one hour. The ethanol was removed in vacuo and replaced with water. The aqueous solution was extracted with ether (20 mL) and acidified to pH 4 with concentrated hydrochloric acid (16 mL). A solid soon precipitated, and this was filtered, washed with water, air dried, and recrystallized from ethyl acetate (2 crops) to afford 2.03 g (75%) of fine pale tan needles; mp 119°-120° C.

Source