Reaktion #2376664

Reaktionsgleichung

nitric acid

cyanamide

5-Amino-2-methylbenzothiazole dihydrochloride

sodium bicarbonate

→

title compound

Ausbeute 47.9%

5-Guanidino-2-methylbenzothiazole nitrate

Ausbeute 47.9%

Lösungsmittel

water

dichloromethane

ethanol

Reaktionsbedingungen

Aufarbeitung

1. 1
   TrocknenThe organic phase was dried (MgSO4)
2. 2
   Sonstigeevaporated
3. 3
   Sonstigeto afford the free base which
4. 4
   Temperaturthe resulting mixture was refluxed for 18 h
5. 5
   SonstigeThe solid which formed
6. 6
   Sonstigewas collected
7. 7
   Waschenwashed with cold ethanol

Vorschrift

5-Amino-2-methylbenzothiazole dihydrochloride (2.50 g, 10.54 mmol) was partitioned between dichloromethane and saturated aqueous sodium bicarbonate solution. The organic phase was dried (MgSO4) and evaporated to afford the free base which was dissolved in ethanol (5 ml). A solution of cyanamide (660 mg, 15.71 mmol) in water (1 ml) was added followed by concentrated nitric acid (69%, 0.68 ml, 10.54 mmol) and the resulting mixture was refluxed for 18 h. The solid which formed on cooling to room temperature was collected and washed with cold ethanol then diethyl ether to give the title compound (1.36 g) as a beige solid m.p. 260-261° (dec.). δH (d6DMSO) 2.80 (3H, s), 7.26 (1H, m), 7.37 (4H, s), 7.78 (1H, s), 8.08 (1H, d, J 8.6 Hz) and 9.67 (1H, br s).

Quelle