Synthesis
General procedure for the synthesis of 6-aminobenzothiazole from 6-nitrobenzothiazole: 6-nitrobenzothiazole (6.13 mmol) was dissolved in ethanol (30 mL), and 10% Pd/C catalyst was added (20% of the mass of 6-nitrobenzothiazole was used as catalyst). The mixture was placed in a Parr hydrogenation unit and reacted overnight at 50 psi hydrogen pressure. Upon completion of the reaction, the catalyst was removed by filtration and the filtrate was concentrated under vacuum to remove the solvent. Finally, purification by fast chromatography using a 30%-40% ethyl acetate/hexane gradient elution gave pure 6-aminobenzothiazole.
Purification Methods
It crystallises from aqueous EtOH, pet ether or *C6H6/pet ether. The hydrochloride has m 305o(dec) from dilute HCl, and the picrate has m 185o(dec ) from Me2CO. [Boggust & Cocker J Chem Soc 360 1949, Beilstein 27 III/IV 4884.]
References
[1] Advanced Synthesis and Catalysis, 2010, vol. 352, # 11-12, p. 1834 - 1840
[2] Bioorganic and Medicinal Chemistry, 2009, vol. 17, # 19, p. 7002 - 7007
[3] Synthesis, 2005, # 4, p. 600 - 604
[4] Journal of Organic Chemistry, 2011, vol. 76, # 21, p. 8726 - 8736
[5] Molecules, 2014, vol. 19, # 1, p. 925 - 939
