Potassium Hydroxide → N-Hydroxy Riluzole

HRID 482271

Reaktionsgleichung

Reaktionsgleichung von HRID 482271
Cl.[NH2:2][OH:3].[OH-].[K+].Cl[C:7]1[S:8][C:9]2[CH:15]=[C:14]([O:16][C:17]([F:20])([F:19])[F:18])[CH:13]=[CH:12][C:10]=2[N:11]=1>CO>[OH:3][NH:2][C:7]1[S:8][C:9]2[CH:15]=[C:14]([O:16][C:17]([F:20])([F:19])[F:18])[CH:13]=[CH:12][C:10]=2[N:11]=1

Komponenten

5

Edukt 3

HCID 14797Potassium HydroxideHCID 443297Hydroxyamine hydrochlorideHCID 100379242-Chloro-6-(trifluoromethoxy)-1,3-benzothiazole

Produkt 1

HCID 9859774N-Hydroxy RiluzoleAusbeute 56,3 %

Reagenzien, Katalysatoren, Lösungsmittel 1

HCID 887MethanolLösungsmittel

Reaktionsbedingungen

Temperatur
20 °C

Versuchsvorschrift

21.81 g of hydroxylamine hydrochloride are added to 17.61 g of potassium hydroxide in solution in 350 ml of methanol at a temperature in the region of 20° C. and the reaction mixture is brought to reflux for 10 minutes. 13.24 g of 2-chloro-6-(trifluoromethoxy)benzothiazole are then added and the reaction is continued at reflux for 5 hours. After cooling to a temperature in the region of 20° C., the precipitate formed is filtered off and the filtrate concentrated to dryness under reduced pressure (15 mm Hg, 2 kPa). The crude product thus obtained is purified by flash chromatography on a silica column, using an ethyl acetate/cyclohexane (20/80 by volume) mixture as eluent. 7.35 g of 2-hydroxyamino-6-(trifluoromethoxy)benzothiazole are thus isolated in the form of an orangey-yellow powder melting with decomposition at 119° C. [(Analysis % calculated C: 38.40, H: 2.01, F: 22.78, N: 11.20, S: 12.82; % found C: 38.7, H: 1.9, F: 22.3, N: 11.1, S: 12.6); 1H N.M.R. spectrum (250 MHz, d6-(CD3)2SO, at a temperature of 373 K, δ in ppm): 7.22 (mt, 2H, H 4 and H 5), 7.62 (broad s, 1H, H 7), 9.55 and from 9.50 to 11.00 (respectively broad s and unresolved peak, each 1H, NHOH)].

Aufarbeitung

  1. temperatureto reflux for 10 minutes
  2. temperatureat reflux for 5 hours
  3. customthe precipitate formed
  4. filtrationis filtered off
  5. concentrationthe filtrate concentrated to dryness under reduced pressure (15 mm Hg, 2 kPa)
  6. customThe crude product thus obtained
  7. customis purified by flash chromatography on a silica column

Quellen und Nachweise

ORD-Eintrag
ord-618ea9f6077640998d84e49737d960eb
Quelldatensatz
uspto-grants-1998_08
Patentnummer
US05795903

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