Water → 5-Bromo-2-methyl-1,2,6,7,8,9-hexahydro-3h-cyclopenta[a]naphthalen-3-one

In a three-necked round-bottom 500 ml flask equipped with a reflux condenser, dropping funnel with pressure-equalizing, and mechanical stirrer a solution of 55.0 g (0.275 mol) of 2-methyl-1,2,6,7,8,9-hexahydro-3H-cyclopenta[a]naphthalen-3-one in 50 ml of CH2Cl2 was added dropwise with vigorous stirring for 1 h at −10° C. to a suspension of 92 g (0.69 mol) of AlCl3 in 100 ml of CH2Cl2. This mixture was stirred additionally for 1 h at this temperature; then 14.2 ml (44.0 g, 0.275 mol) of bromine was added dropwise with vigorous stirring for 1 h. The resulting mixture was stirred for 2 h at −10° C. and then overnight at ambient temperature, and, then, it was poured on 1000 cm3 of cold water. The organic layer was separated, the aqueous layer was extracted with 3×200 ml of methyl-tert-butyl ether. The combined extract was washed with saturated aqueous Na2SO3 to eliminate bromine and with aqueous Na2CO3. It was then dried over K2CO3, and evaporated to dryness. Fractional distillation gave a yellowish liquid, b.p. 195-198° C./4 mm Hg. Yield 58.3 g (76%).

1. customIn a three-necked round-bottom 500 ml flask equipped with a reflux condenser
2. additionwas added dropwise
3. stirringwith vigorous stirring for 1 h
4. stirringThe resulting mixture was stirred for 2 h at −10° C.
5. customThe organic layer was separated
6. extractionthe aqueous layer was extracted with 3×200 ml of methyl-tert-butyl ether
7. extractionThe combined extract
8. washwas washed with saturated aqueous Na2SO3
9. dry with materialIt was then dried over K2CO3
10. customevaporated to dryness
11. distillationFractional distillation
12. customgave a yellowish liquid, b.p. 195-198° C./4 mm Hg

ORD-Eintrag

ord-2cd29d286f9c4850ba73c009f7ea9e4e

Quelldatensatz

uspto-grants-2008_11

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US07446216B2