Hydrochloric Acid → 5-Isothiocyanatoisophthalic acid

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Reaction Steps

Carbon disulfide (0.26 mL, 4.4 mmol) was added to a mixture comprising 5-aminoisophthalic acid (0.30 g, 1.5 mmol), tetrahydrofuran (1.0 mL), water (1.0 mL) and triethylamine (0.51 mL, 3.6 mmol), followed by stirring at room temperature for 61hours. The obtained reaction mixture was dropwise added to a tetrahydrofuran (1.0 mL) solution of iodine (0.41 g, 1.6 mmol) over a period of 5 minutes at 0° C., followed by stirring at 0° C. for further two hours. Thereafter, 1M hydrochloric acid (1.5 mL) and sodium sulfite (38 mg, 0.30 mmol) were added and mixed. Then, ethyl acetate (6 mL) was added, and the organic layer was separated and concentrated under reduced pressure to dryness. To the residue, ethyl acetate (5 mL) was added and thoroughly mixed. Then, the insoluble matter was filtered off. The filtrate was concentrated under reduced pressure to dryness to obtain 5-isothiocyanatoisophthalic acid as a cream-colored solid (0.33 g, yield: 100%, HPLC purity: 88%, HPLC retention time: 2.8min). LC-MS ES-222 (retention time: 3.7 min, condition 1).

Provenance & Evidence