Hydrochloric Acid → 4-Bromo-6-isopropyl-2-methyl-1H-indene

Temperature

0 °C

To a solution of 22.2 g (83.2 mmol) of 7-bromo-5-isopropyl-2-methyl-1-indanone in 120 ml of THF-methanol (2:1, vol.), 5.06 g (133 mmol) of NaBH4 was added with vigorous stirring over 3 h at 0° C. This mixture was stirred overnight at room temperature; then, 300 ml of cold water was added, and the resulting mixture was acidified with 1 M HCl to pH 1. The organic layer was separated, and the aqueous layer was extracted with 3×150 ml of dichloromethane. The combined organic fractions were dried over K2CO3 and evaporated to dryness, and 200 ml of toluene was added to the yellowish oil obtained. This toluene solution was treated with a catalytic amount of pTolSO3H (ca. 0.2 g) for 1 h at reflux, cooled to room temperature, and evaporated to dryness. The crude product was purified using flash chromatography on Silica Gel 60 (40-63 μm, d 40 mm, l 400 mm; eluent: hexanes). Yield 19.6 g (94%) of 4-bromo-6-isopropyl-2-methyl-1H-indene.

1. stirringThis mixture was stirred overnight at room temperature
2. customThe organic layer was separated
3. extractionthe aqueous layer was extracted with 3×150 ml of dichloromethane
4. dry with materialThe combined organic fractions were dried over K2CO3
5. customevaporated to dryness, and 200 ml of toluene
6. additionwas added to the yellowish oil
7. customobtained
8. temperatureat reflux
9. temperaturecooled to room temperature
10. customevaporated to dryness
11. customThe crude product was purified

ORD record

ord-b2a37f91552b47a8b55de325ebde984c

Source dataset

uspto-grants-2011_03

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07910783B2