Hydrochloric Acid → 2-Chloro-1-cyclopentylethanone

Temperature

0 °C

Cyclopentanecarbonyl chloride (5.0 g, 0.038 mol) was dissolved in THF (100 mL) and cooled to 0° C. The solution was treated with a 2M solution of TMS-Diazomethane in hexanes (56.56 mL, 0.113 mol) over 10 min. The resulting yellow solution was allowed to stand at room temperature for 12 hours. The solution was then concentrated and the residue was dissolved in THF (100 mL) and treated slowly with a 4N HCl in Dioxane solution (28.28 mL, 0.113 mol). The result was allowed to stir at 24° C. for 2 hours. The solution was concentrated to an oil which was chromatographed on silica gel eluting with 5% EtOAc in Hexanes to give the intermediate depicted below (4.9 g, 88%).

1. concentrationThe solution was then concentrated
2. dissolutionthe residue was dissolved in THF (100 mL)
3. concentrationThe solution was concentrated to an oil which
4. customwas chromatographed on silica gel eluting with 5% EtOAc in Hexanes
5. customto give the intermediate

ORD record

ord-fa348b4e4831437eb76ccb6a3eecafac

Source dataset

uspto-grants-2006_12

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07148226B2