Sodium Hydroxide → Acetic acid, (6-fluoro-2,3-dihydro-3,3-dimethyl-1H-inden-1-ylidene)-, (2E)-

Temperature

0 °C

A solution of ethyl 2-(6-fluoro-1-hydroxy-3,3-dimethyl-1-indanyl)acetate (16 g, 0.0601 mol) in 1N sodium hydroxide (60.1 ml, 0.0601 mol) and ethanol (60 ml) was stirred for 20 h. The solution was concentrated to a small volume by spin evaporation in vacuo, diluted with deionized water (100 ml), and acidified to pH 3 with 1N hydrochloric acid. This biphasic solution was extracted with dichloromethane (2×100 ml). The extracts were combined, washed with deionized water (20 ml), dried with magnesium sulfate (Mallinckrodt), and concentrated by spin evaporation in vacuo. The residue was dissolved in dichloromethane (30 ml), cooled to 0° C., and diluted with 400 ml of a cold (0° C.) solution of trifluoroacetic acid (45 g, Aldrich) in dichloromethane (400 ml). After 15 min, the solution was concentrated by spin evaporation in vacuo and the residue was crystallized by adding hexanes to give 9.23 g (70%) of (E)-2-(6-fluoro-3,3-dimethyl-1-indanylidene)acetic acid as a white crystalline solid, m.p., 202-203.5° C.:

1. concentrationThe solution was concentrated to a small volume by spin evaporation in vacuo
2. additiondiluted with deionized water (100 ml)
3. extractionThis biphasic solution was extracted with dichloromethane (2×100 ml)
4. washwashed with deionized water (20 ml)
5. dry with materialdried with magnesium sulfate (Mallinckrodt)
6. concentrationconcentrated by spin evaporation in vacuo
7. dissolutionThe residue was dissolved in dichloromethane (30 ml)
8. additiondiluted with 400 ml of a cold (0° C.) solution of trifluoroacetic acid (45 g, Aldrich) in dichloromethane (400 ml)
9. concentrationthe solution was concentrated by spin evaporation in vacuo
10. customthe residue was crystallized
11. additionby adding hexanes

ORD record

ord-ff6b0d611950456f830ebbdc068d21ea

Source dataset

uspto-grants-2000_09

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06124284