Cyclohexene → 3-Methyl-2,3,4,5,6,7-hexahydro-1H-inden-1-one

Cyclohexene (27.3 g, 0.33 mol), crotonic acid (28.7 g, 0.33 mol) and polyphosphoric acid (300 ml) were mechanically stirred under a nitrogen atmosphere at 60° C. for 30 minutes. The slurry was poured into water and the aqueous solution extracted with diethyl ether. The diethyl ether extract was washed successively with a 10 percent NaHCO3 solution and a saturated NaCl solution. The organic extract was then dried over anhydrous MgSO4. The solution was then filtered and the solvent removed under reduced pressure. The crude product was then purified via vacuum distillation (bp 87°-92° C. at 5 mm) to give 32.6 g (66 percent) of purified material.

1. extractionthe aqueous solution extracted with diethyl ether
2. extractionThe diethyl ether extract
3. washwas washed successively with a 10 percent NaHCO3 solution
4. extractionThe organic extract
5. dry with materialwas then dried over anhydrous MgSO4
6. filtrationThe solution was then filtered
7. customthe solvent removed under reduced pressure
8. distillationThe crude product was then purified via vacuum distillation (bp 87°-92° C. at 5 mm)

ORD record

ord-77cee2d2e36b4a10abdd79a9928bd8fe

Source dataset

uspto-grants-1998_02

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US05721185