Synthesis
Step 2. Preparation of 2-(methylmercapto)benzo[d]thiazol-6-ol: 2-mercaptobenzo[d]thiazol-6-ol (3.80 g, 20.76 mmol, 1.0 eq.) obtained from Step 1 was dissolved in dichloromethane (40 mL, 0.5 M) and cooled to 0 °C in an ice bath. Under stirring, triethylamine (7.29 mL, 51.91 mmol, 2.5 eq.) and iodomethane (1.93 mL, 31.14 mmol, 1.5 eq.) were added sequentially. The reaction temperature was maintained between 0 °C and -10 °C with continuous stirring for 3 hours. Upon completion of the reaction, the solvent was removed by rotary evaporator under reduced pressure. Water (~200 mL) was added to the residue and the aqueous layer was subsequently extracted with ethyl acetate (3 x 150 mL). The organic layers were combined, dried over anhydrous sodium sulfate, filtered and concentrated under reduced pressure to afford 2-(methylmercapto)benzo[d]thiazol-6-ol (3.76 g, 92% yield) in light green powder form.
References
[1] Patent: US2008/45528, 2008, A1. Location in patent: Page/Page column 47
[2] Australian Journal of Chemistry, 1979, vol. 32, # 12, p. 2713 - 2726