Hydrochloric Acid → 4-Isothiocyanatobenzoic acid

Participants

Reaction Steps

Carbon disulfide (0.67 mL, 11 mmol) was added to a mixture comprising 4-aminobenzoic acid (0.50 g, 3.6 mmol), N,N-dimethylformamide (6.3 mL) and triethylamine (1.3 mL, 9.3 mmol), followed by stirring at room temperature for 4 hours. To the obtained reaction mixture, bromine (0.20 mL, 3.8 mmol) was dropwise added over a period of 20 minutes at 0° C., followed by stirring at 0° C. for further two hours. Thereafter, 1M hydrochloric acid (3.6 mL), sodium sulfite (0.092 g, 0.72 mmol) and water (5.0 mL) were added and mixed. Then, ethyl acetate (15 mL) was added, and the solid was collected by filtration and washed with ethyl acetate (1.0 mL). Obtained crystals were dried under reduced pressure at 50° C. to obtain 4-isothiocyanatobenzoic acid as a slightly yellow solid (0.16 g, yield: 25%, HPLC purity: 94%, HPLC retention time: 3.7 min).

Provenance & Evidence