Chemical Properties
white to light beige or greyish crystalline powder
Uses
2-Amino-4-chlorobenzothiazole is a benzothiazole derivative that shows in vivo antiviral effects against various influenza A2 strains.
General Description
Cream colored crystalline solid.
Air & Water Reactions
Insoluble in water.
Reactivity Profile
A halogenated amine, organosulfide. Organosulfides are incompatible with acids, diazo and azo compounds, halocarbons, isocyanates, aldehydes, alkali metals, nitrides, hydrides, and other strong reducing agents. Reactions with these materials generate heat and in many cases hydrogen gas. Many of these compounds may liberate hydrogen sulfide upon decomposition or reaction with an acid. Amines are chemical bases. They neutralize acids to form salts plus water. These acid-base reactions are exothermic. The amount of heat that is evolved per mole of amine in a neutralization is largely independent of the strength of the amine as a base. Amines may be incompatible with isocyanates, halogenated organics, peroxides, phenols (acidic), epoxides, anhydrides, and acid halides. Flammable gaseous hydrogen is generated by amines in combination with strong reducing agents, such as hydrides.
Health Hazard
ACUTE/CHRONIC HAZARDS: When heated to decomposition 2-AMINO-4-CHLOROBENZOTHIAZOLE emits very toxic fumes of chloride ion, SOx and NOx.
Fire Hazard
Flash point data for 2-AMINO-4-CHLOROBENZOTHIAZOLE are not available; however, 2-AMINO-4-CHLOROBENZOTHIAZOLE is probably combustible.
Synthesis
GENERAL METHOD: A solution of o-chloroaniline (2 mmol) in acetonitrile (15 mL) was slowly added to a solution of potassium thiocyanate (8 mmol) in acetonitrile (15 mL). Subsequently, nano BF3/SiO2 catalyst (0.06 g, 30 mol% BF3) was added to the reaction system and the mixture was placed in an ice-salt bath and mechanically stirred for 30 min. A solution of bromine (4 mmol, 0.2 mL) in acetonitrile (3 mL) was slowly added through a dropping funnel, and the rate of dropping was controlled to ensure that the reaction temperature did not exceed 0 °C. After the bromine solution was added, the reaction mixture continued to be stirred at room temperature for 4 h, during which the progress of the reaction was monitored by TLC. Upon completion of the reaction, the mixture was poured into water and heated to 70 °C on a steam bath followed by thermal filtration to isolate the catalyst. The catalyst was washed with acetone and recycled for reuse. The filtrate was neutralized with 10% NaOH solution and the resulting precipitate was collected by filtration, dried and recrystallized from ethanol (10 mL) to give the target product 2-amino-4-chlorobenzothiazole. All products were characterized by physical properties and spectral data including FT-IR, 1H NMR and 13C NMR and confirmed by comparison with known standards.
References
[1] Synlett, 2012, vol. 23, # 15, p. 2219 - 2222
[2] Research on Chemical Intermediates, 2016, vol. 42, # 12, p. 7855 - 7868
[3] Patent: WO2017/25980, 2017, A2. Location in patent: Page/Page column 9; 12
[4] Asian Journal of Chemistry, 2011, vol. 23, # 9, p. 3969 - 3974
[5] European Journal of Medicinal Chemistry, 2013, vol. 67, p. 1 - 13
