Benzocaine → Ethyl 2-Aminobenzothiazole-6-carboxylate

Participants

Reaction Steps

A solution of ethyl-4-aminobenzoate (35 g, 212 mmol) in glacial acetic acid (300 mL) was added to a stirred solution of sodium thiocyanate (69 g, 848 mmol) in acetic acid (150 mL). The mixture was cooled in an ice-water bath and a solution of bromine (12 mL, 233 mmol) in acetic acid (60 mL) was added dropwise via an addition funnel. The reaction mixture was stirred at 0° C. to RT for 4 h and then poured into water (1.5 L). Saturated sodium carbonate solution was added to neutralize the solution. Precipitated solid was filtered, washed with water and EtOAc, and dried in vacuo to obtain the title compound of this step (31.65 g, 67.2% yield).

Provenance & Evidence