Hydrochloric Acid → 5-Isothiocyanatoisophthalic acid

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).

1. customThe obtained reaction mixture
2. stirringby stirring at 0° C. for further two hours
3. additionmixed
4. customthe organic layer was separated
5. concentrationconcentrated under reduced pressure to dryness
6. additionTo the residue, ethyl acetate (5 mL) was added
7. additionthoroughly mixed
8. filtrationThen, the insoluble matter was filtered off
9. concentrationThe filtrate was concentrated under reduced pressure to dryness

ORD record

ord-2e72fb63036141209330a51826f48bb6

Source dataset

uspto-grants-2013_02

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08367857B2