Acetic Acid → 6-Fluoro-2-oxiranyl-1-benzopyran

Temperature

0 °C

2-Chloro-1-(6-fluoro-1-benzopyran-2-yl)-ethanol (2.5 g, 9.20 mmol, 84.9% A) was dissolved in i-PrOH (25 ml) under nitrogen and the reaction mixture cooled to 0° C. A 2M aqueous solution of NaOH (12.5 ml) was added to the solution over 5 min and the reaction was stirred for 1 hour 30 min. The reaction mixture was then diluted with toluene (50 ml) and the pH corrected with acetic acid (0.92 g). Toluene (50 ml) and demineralized water (10 ml) were then added to the mixture and the phases separated after extraction. The collected organic phases were then washed with demineralized water (50 ml). The toluene phase was then anhydrified by azeotropic distillation and concentrated until dryness in a rotary evaporator to give 6-Fluoro-2-oxiranyl-1-benzopyran as a mixture of diastereoisomers 52:48 (2.0 g, 96% yield, 86.1% A).

1. customthe phases separated
2. extractionafter extraction
3. washThe collected organic phases were then washed with demineralized water (50 ml)
4. distillationThe toluene phase was then anhydrified by azeotropic distillation
5. concentrationconcentrated until dryness in a rotary evaporator

ORD record

ord-cd0425df7508463d96175d685f52beb1

Source dataset

uspto-grants-2015_03

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08981127B2