Benzene → 3,3-Dimethyl-1-indanone

A solution of 25.0 g (0.25 moles) of 3,3-dimethyl acrylic acid in 250 ml of benzene was cooled to 0° C. in an ice bath. To this solution, 99 g (0.75 moles) of anhydrous aluminum chloride was slowly added using a spatula over a period of 20 minutes with stirring, after which the ice bath was removed and the reaction mixture was gradually heated to reflux. The reaction mixture was refluxed for ˜7-8 h, then excess benzene was distilled off and the mixture was quenched with ice-cold dilute hydrochloric acid (HCl). The mixture was then diluted with ethylacetate (100 ml), the organic layer was separated and the aqueous layer was again washed with ethyl acetate (50 ml). The combined organic layer was washed with water (3×100 ml) until the pH was neutral, and then dried over anhydrous sodium sulfate and concentrated under vacuum. 43.0 g of reddish brown liquid was obtained, which was distilled under vacuum to give 29 g of the desired product, 3,3-dimethyl-indan-1-one (distilled at 82-84° C. at ˜10 mm). Yield=73%, purity=99%. 1H NMR (DMSO-d6, 300 MHz): δ 7.3-7.8 (m, 4H, Ar-H), δ 2.5 (s, 2H, O═C—CH2), δ 1.3 (s, 6H, —CH3). LC/MS: 161 (M+1).

1. customof 20 minutes
2. customafter which the ice bath was removed
3. temperaturethe reaction mixture was gradually heated to reflux
4. temperatureThe reaction mixture was refluxed for ˜7-8 h
5. distillationexcess benzene was distilled off
6. customthe mixture was quenched with ice-cold dilute hydrochloric acid (HCl)
7. additionThe mixture was then diluted with ethylacetate (100 ml)
8. customthe organic layer was separated
9. washthe aqueous layer was again washed with ethyl acetate (50 ml)
10. washThe combined organic layer was washed with water (3×100 ml) until the pH
11. dry with materialdried over anhydrous sodium sulfate
12. concentrationconcentrated under vacuum

ORD record

ord-3a122c6d4bcf4e94950470b56d42526d

Source dataset

uspto-grants-2015_08

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US09102598B2