Hydrochloric Acid → [2-(1-Cyano-3-methyl-butylcarbamoyl)-cyclohexyl]-carbamic acid benzyl ester

To a 0° C. solution of the amide of step 3 (13.2 g, 33.9 mmol) in 150 mL of anhydrous pyridine was added trifluoroacetic anhydride (5.50 mL, 38.9 mmol) dropwise slowly over a 3 min period. The reaction mixture was stirred for 15 min and then poured into a slurry of ice and 1N HCl solution. The mixture was extracted with 500 mL of ethyl acetate, and washed with three 400 mL portions of 1N HCl, 400 mL of water, dried over sodium sulfate, filtered and concentrated to give a crude solid. Recrystallization from ethyl acetate/hexanes gave 11.3 g of [2-(1-Cyano-3-methyl-butylcarbamoyl)-cyclohexyl]-carbamic acid benzyl ester as a white solid. Yield: 90%, MS: 394 (M+Na+), mp=103.6-106.5° C.

1. extractionThe mixture was extracted with 500 mL of ethyl acetate
2. washwashed with three 400 mL portions of 1N HCl, 400 mL of water
3. dry with materialdried over sodium sulfate
4. filtrationfiltered
5. concentrationconcentrated
6. customto give a crude solid
7. customRecrystallization from ethyl acetate/hexanes

ORD-Eintrag

ord-bc423b0b15aa42a5945bed9994fd58e4

Quelldatensatz

uspto-grants-2007_11

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US07300934B2