3-ethoxybenzenethiol

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: The title compound was prepared in 67% yield (1.29 g, yellow oil) from tert-butyl 4-((methylsulfonyl)oxy)piperidine-1-carboxylate (1.60 g, 5.73 mmol) and 3-ethoxybenzenethiol (1.06 g, 6.87 mmol) by the similar manner in Step-1 of Intermediate-4.

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: Part A: A mixture of 3-ethoxythiophenol (10.0 g, 0.065 mol), 2-amino-5-bromothiazole monohydrobromide (17.7 g, 0.068 mol), 1 M aqueous NaOH (200 mL), and THF (200 mL) was stirred at RT for 15 min. The reaction mixture was warmed to 55° C. over 1 h, cooled to RT and concentrated under reduced pressure to remove THF. The residue was partitioned between EtOAc (ca. 500 mL) and water (ca 100 mL), and the layers were separated. The organic phase was washed with saturated aqueous NaCl (1×200 mL), dried (Na2SO4), and concentrated under reduced pressure to give a solid. The solid was triturated with CH2Cl2:hexanes (ca. 10:1) to provide 5-(3-ethoxy-phenylsulfanyl)-thiazol-2-ylamine (13.2 g, 80%) as a light brown solid. LCMS (m/z): 253 (M+H)+ The reaction mixture was warmed to 55° C. over 1 h cooled to RT concentrated under reduced pressure to remove THF The residue was partitioned between EtOAc (ca. 500 mL) and water (ca 100 mL) the layers were separated The organic phase was washed with saturated aqueous NaCl (1×200 mL) dried (Na2SO4) concentrated under reduced pressure to give a solid The solid was triturated with CH2Cl2