反应详情

To a solution of 35.5 g of sodium salt of [o-(3-chloro-o-toluidino)-phenyl]-glyoxylic acid in 455 ml of abs. ethanol are added at 50° 28.5 g of hydrazine hydrate, and 5 minutes afterwards 66.2 g of sodium methylate. The solution is thereupon heated in an oil bath with a bath temperature of 150°, whereby the ethanol slowly distills off. To the solution are simultaneously added dropwise 455 ml of ethylene glycol monoethyl ether. The internal temperature thereby increases to 130°. After the dropwise addition is completed, the solution is stirred for a further hour at 150°; it is then cooled and diluted with 3,000 ml of water. The solution is extracted twice with 300 ml of ether each time, and then acidified with concentrated hydrochloric acid. The precipitated yellow oil is extracted with 200 ml of ethyl acetate; the ethyl acetate solution is washed with 200 ml of water, dried over sodium sulphate, and concentrated at 30° under 11 Torr, whereby [ o-(3-chloro-o-toluidino)-phenyl]-acetic acid crystallises out, M.P. 124°-125°.

1. distillationslowly distills off
2. additionTo the solution are simultaneously added dropwise 455 ml of ethylene glycol monoethyl ether
3. temperatureThe internal temperature thereby increases to 130°
4. additionAfter the dropwise addition
5. temperatureit is then cooled
6. additiondiluted with 3,000 ml of water
7. extractionThe solution is extracted twice with 300 ml of ether each time
8. extractionThe precipitated yellow oil is extracted with 200 ml of ethyl acetate
9. washthe ethyl acetate solution is washed with 200 ml of water
10. dry with materialdried over sodium sulphate
11. concentrationconcentrated at 30° under 11 Torr, whereby [ o-(3-chloro-o-toluidino)-phenyl]-acetic acid
12. customcrystallises out