Reaktion #430545

Reaktionsgleichung

citric acid

Sodium hydride

2-amino-5-bromo-3-methylpyrazine

5-dimethylamino-1-naphthalenesulphonyl chloride

→

5-dimethylamino-N-(5-bromo-3-methyl-2-pyrazinyl)-1-naphthalenesulphonamide

Ausbeute 33.0%

Lösungsmittel

1,2-dimethoxyethane

Reaktionsbedingungen

Aufarbeitung

1. 1
   Extraktionthe reaction was extracted with dichloromethane (3×25 ml)
2. 2
   TrocknenThe combined extracts were dried (MgSO4)
3. 3
   Sonstigeevaporated
4. 4
   Sonstigeto give a brown oil
5. 5
   SonstigeThe oil was purified by chromatography on silica gel
6. 6
   Wascheneluting with dichloromethane/diethyl ether (1:1)

Vorschrift

Sodium hydride (60% dispersion in mineral oil; 0.1 g) was added portionwise to a stirred solution of 2-amino-5-bromo-3-methylpyrazine (0.188 g) in 1,2-dimethoxyethane (DHE; 4 ml). After 5 minutes 5-dimethylamino-1-naphthalenesulphonyl chloride (0.3 g) was added, in a single portion, and the reaction was allowed to a stir for 18 hours. 2M Aqueous citric acid solution (10 ml) was added and the reaction was extracted with dichloromethane (3×25 ml). The combined extracts were dried (MgSO4) and evaporated to give a brown oil. The oil was purified by chromatography on silica gel, eluting with dichloromethane/diethyl ether (1:1) to give 5-dimethylamino-N-(5-bromo-3-methyl-2-pyrazinyl)-1-naphthalenesulphonamide as a cream solid (0.138 g, 33%), m.p. 171°-172° C.; mass spectrum (+ve FAB, DMSO/methanol/NBA): 421 (M+H)+.

Quelle