3-(Phenylthio)propanoic acid → Thiochroman-4-one

Temperature

60 °C

Polyphosphoric acid (110 g) was admixed with 3-phenylsulfanylpropionic acid (13.54 g, 74 mmol) and the reaction mixture was stirred at 60° C. for 96 h. After cooling to RT, the reaction mixture was admixed with water (250 ml) and extracted with diethyl ether (3×100 ml). The combined organic phases were washed with 5% eq. NaHCO3 solution (50 ml), washed with water (50 ml) and dried over sodium sulfate, and the solvent was removed under reduced pressure. After column chromatography purification of the residue (silica gel, 8:1 cyclohexane/MTBE), the desired product was obtained as a greenish oil (8.0 g, 66% of theory).

1. temperatureAfter cooling to RT
2. extractionextracted with diethyl ether (3×100 ml)
3. washThe combined organic phases were washed with 5% eq. NaHCO3 solution (50 ml)
4. washwashed with water (50 ml)
5. dry with materialdried over sodium sulfate
6. customthe solvent was removed under reduced pressure
7. customAfter column chromatography purification of the residue (silica gel, 8:1 cyclohexane/MTBE)

ORD record

ord-4f1432c601d0431f8fd572aff221794b

Source dataset

uspto-grants-2011_07

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07973072B2