Hydrochloric Acid → 4-Carboxy-2-methylphenylisothiocyanate

Carbon disulfide (0.26 mL, 4.4 mmol) was added to a mixture comprising 4-amino-3-methylbenzoic acid (0.23 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 28 hours. 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 1.5 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 (6 mL) and water (1 mL) were added, and the organic layer was washed once with 1M hydrochloric acid (1 mL) and then concentrated under reduced pressure to dryness to obtain 4-isothiocyanato-3-methylbenzoic acid as a cream-colored solid (0.30 g, yield: 103%, HPLC purity: 88%, HPLC retention time: 4.0 min). LC-MS ES-192 (retention time: 4.3 min, condition 1).

1. customThe obtained reaction mixture
2. stirringby stirring at 0° C. for further 1.5 hours
3. additionmixed
4. customthe organic layer was separated
5. concentrationconcentrated under reduced pressure to dryness
6. additionTo the residue, ethyl acetate (6 mL) and water (1 mL) were added
7. washthe organic layer was washed once with 1M hydrochloric acid (1 mL)
8. concentrationconcentrated under reduced pressure to dryness

ORD record

ord-b9888b077d2a44e88b607df665d6b026

Source dataset

uspto-grants-2013_02

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08367857B2