Hydrochloric Acid → Isochromane

2-phenylethanol (48.8 g,) and paraformaldehyde (15 g,) were mixed and stirred on an ice bath while a stream of hydrogen chloride gas was passed vigorously through the suspension for 2 hr. The ice-bath was removed and the flow of hydrogen chloride was decreased. The mixture was stirred at room temperature for a further 4 hr. during which time the mixture cleared, after which the reaction mixture stood overnight at room temperature. Aqueous sodium hydroxide solution (100 g/100 ml) was added cautiously, with stirring to the reaction mixture over a period of 30 min. The mixture was heated at reflux for 2 hr., cooled and the oil extracted with ether (3×100 ml). The ether layer was dried (magnesium sulphate) and the solvent removed in vacuo. The residue was distilled under vacuum to give isochroman (45.7 g, b.pt 84.5°-85°/8 mmHg)

1. customThe ice-bath was removed
2. waitafter which the reaction mixture stood overnight at room temperature
3. additionAqueous sodium hydroxide solution (100 g/100 ml) was added cautiously
4. stirringwith stirring to the reaction mixture over a period of 30 min
5. temperatureThe mixture was heated
6. temperatureat reflux for 2 hr
7. temperature, cooled
8. extractionthe oil extracted with ether (3×100 ml)
9. dry with materialThe ether layer was dried (magnesium sulphate)
10. customthe solvent removed in vacuo
11. distillationThe residue was distilled under vacuum

ORD record

ord-c60b710fe9704d4c9ea7346492fd5f13

Source dataset

uspto-grants-1989_01

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US04801593