2-METHYL-1,3-BENZOTHIAZOL-6-OL

2-METHYL-1,3-BENZOTHIAZOL-6-OL Property

Melting point:

159-161℃

Boiling point:

28 °C(Press: 3 Torr)

Density 

1.365±0.06 g/cm3(Predicted)

storage temp. 

Sealed in dry,Room Temperature

pka

8.68±0.40(Predicted)

Appearance

Off-white to gray Solid

Safety

Hazard Codes 

Xn

Risk Statements 

22-36/37/38

Safety Statements 

26-36

WGK Germany 

3

HS Code 

2934208090

Hazard and Precautionary Statements (GHS)

Symbol(GHS)

Signal word

Warning

Hazard statements

H301Toxic if swalloed

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.

P405Store locked up.

2-METHYL-1,3-BENZOTHIAZOL-6-OL Chemical Properties,Usage,Production

Uses

2-Methyl-1,3-benzothiazol-6-ol is a useful reactant for the preparation of G protein-biased D2 dopamine receptor partial agonists.

Synthesis

The general procedure for the synthesis of 2-methyl-6-hydroxybenzothiazole from 6-methoxy-2-methylbenzothiazole is as follows: to a dichloromethane solution (10 ml) of 6-methoxy-2-methylbenzothiazole (500 mg, 2.79 mmol) was slowly added to a dichloromethane solution (8.4 ml, 8.40 mmol) of boron bromide (8.4 ml) at -78°C and under nitrogen protection . The reaction mixture was then warmed to 0°C and stirred continuously at this temperature for 1 hour. Upon completion of the reaction, the reaction was quenched by the addition of water to the reaction mixture, followed by extraction with dichloromethane. The combined organic phases were washed sequentially with saturated aqueous sodium bicarbonate and pure water, followed by drying with anhydrous sodium sulfate. The organic layer was concentrated under reduced pressure and the resulting crude product was purified by medium pressure preparative liquid chromatography (Yamazen Corporation, W-Prep 2XY) to give 2-methyl-6-hydroxybenzothiazole (103 mg, 22% yield) as a colorless oil. The structure of the product was confirmed by 1H-NMR (CDCl3, 400 MHz) and mass spectrometry (ESI): 1H-NMR δ 7.66 (1H, d, J = 8.8 Hz), 7.23 (1H, d, J = 2.4 Hz), 6.94 (1H, dd, J = 8.8 Hz, 2.4 Hz), 2.74 (3H, s); MS (ESI, m/z). 166 (M + H)+.

References

[1] Helvetica Chimica Acta, 1992, vol. 75, # 4, p. 1185 - 1197
[2] Patent: EP2258697, 2010, A1. Location in patent: Page/Page column 117
[3] Zhurnal Obshchei Khimii, 1949, vol. 19, p. 1158,1159, 1164; engl. Ausg. S. 1153, 1154,1159
[4] Sb. Statei Obshch. Khim., 1953, p. 1263,1264, 1266, 1271
[5] Chem.Abstr., 1955, p. 5443