5-Methyl-2-aminobenzothiazole

5-Methyl-2-aminobenzothiazole Property

Melting point:

182-184 °C(Solv: benzene (71-43-2))

Boiling point:

322.0±35.0 °C(Predicted)

Density 

1.315±0.06 g/cm3(Predicted)

storage temp. 

Keep in dark place,Inert atmosphere,Room temperature

pka

4.31±0.10(Predicted)

Appearance

White to off-white Solid

CAS DataBase Reference

14779-17-0(CAS DataBase Reference)

Safety

HS Code 

29342000

Toxicity

mouse,LD50,intravenous,74mg/kg (74mg/kg),Journal of Pharmacology and Experimental Therapeutics. Vol. 105, Pg. 486, 1952.

Hazard and Precautionary Statements (GHS)

Symbol(GHS)

Signal word

Warning

Hazard statements

H302Harmful if swallowed

H315Causes skin irritation

H319Causes serious eye irritation

H335May cause respiratory irritation

Precautionary statements

P261Avoid breathing dust/fume/gas/mist/vapours/spray.

P305+P351+P338IF IN EYES: Rinse cautiously with water for several minutes. Remove contact lenses, if present and easy to do. Continuerinsing.

5-Methyl-2-aminobenzothiazole Chemical Properties,Usage,Production

Synthesis

GENERAL METHOD: A solution of 3-methylaniline (2 mmol) in acetonitrile (15 ml) was added to a solution of potassium thiocyanate (8 mmol) in acetonitrile (15 ml). Subsequently, 0.06 g (30 mol% BF3) of BF3/SiO2 nanoparticles was added to the mixture and the mixture was placed in an ice salt bath and mechanically stirred for 30 min. Then, a solution of bromine (4 mmol, 0.2 ml) in acetonitrile (3 ml) was slowly added through a dropping funnel, controlling the rate of addition to ensure that the reaction temperature did not exceed 0 °C. After complete addition of bromine, the reaction mixture was 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 remove the catalyst. The catalyst was washed with acetone and recycled for reuse. The filtrate was neutralized with 10% NaOH solution and the precipitate was collected, dried and recrystallized from ethanol (10 ml) to give 2-amino-5-methylbenzothiazole. The product was characterized by physical properties and spectral data (including melting point, FT-IR, 1H NMR and 13C NMR) and confirmed by comparison with known standards. Spectral data of the selected products: 6-bromo-1,3-benzothiazol-2-amine (2e) as a yellow solid; yield = 93%; melting point = 202-204 °C (literature value 203 °C); FT-IR (KBr) ν/cm-1: 3315, 3012, 2835, 1580, 1476, 1261, 920, 742, 512; 1H NMR ( 400MHz, CDCl3) δ ppm: 5.44 (s, 2H, NH2), 7.4-7.5 (d, 2H, Ar-H), 7.71 (s, 1H, Ar-H); 13C NMR (100MHz, DMSO-d6) δ ppm: 119, 120.9, 125.15, 126.07, 133.1, 152.15, 167.75. 152.15, 167.75.

References

[1] Research on Chemical Intermediates, 2016, vol. 42, # 12, p. 7855 - 7868
[2] Journal of Pharmaceutical Sciences, 1994, vol. 83, # 10, p. 1425 - 1432