Welcome to chemicalbook!
Chinese English Japanese Germany Korea
010-86108875
Try our best to find the right business for you.
Do not miss inquiry messages Please log in to view all inquiry messages.

Welcome back!

ChemicalBook CAS DataBase List CarbaMic acid, N-[(1S)-2-[3,5-bis(trifluoroMethyl)phenyl]-1-Methyl-2-oxoethyl]-, phenylMethyl ester
871917-79-2

CarbaMic acid, N-[(1S)-2-[3,5-bis(trifluoroMethyl)phenyl]-1-Methyl-2-oxoethyl]-, phenylMethyl ester synthesis

5synthesis methods
114744-83-1 Synthesis
(2-OXO-2-PHENYL-ETHYL)-CARBAMIC ACID TERT-BUTYL ESTER

114744-83-1
26 suppliers
inquiry

CarbaMic acid, N-[(1S)-2-[3,5-bis(trifluoroMethyl)phenyl]-1-Methyl-2-oxoethyl]-, phenylMethyl ester

871917-79-2
4 suppliers
inquiry

-

Yield:99.9 % ee

Reaction Conditions:

Stage #1: 3,6-bis(trifluoromethyl)bromobenzene;(S)-benzyl (1-(N,O-dimethylhydroxylamine)-1-oxopropan-2-yl)carbamatewith isopropylmagnesium chloride in tetrahydrofuran at -10 - 20;
Stage #2: with hydrogenchloride in tetrahydrofuran;water at 0 - 5; for 2 h;

Steps:

2

The Weinreb amide from Step 1 (6kg, 22.5 mol) and 3,5-bis(trifluoromethyl)bromobenzene (4.85L, 28.1mol) are dissolved in anhydrous THF (24L). The solution is purged with nitrogen to remove distilledoxygen. The solution is cooled to -10°C and iso-PrMgCl in THF (56.4 mol) is slowly added (2 hours) tothe reaction via addition funnel, maintaining a reaction temperature < - 5 °C. The solution is allowed to warm to 20°C and aged overnight at 20° C. The reaction is then cooled to -10°C under nitrogen and isquenched slowly over 2 hours into 5N HC1 (14L) that is maintained at 0-5°C. MTBE (60L) is added andthe biphasic mixture is agitated for 5 min. After warming to 20°-25°C, it is allowed to settle for 30 min,and then the layers are separated. The organic layer is washed with water twice (12L).The organic layer is vacuum transferred through a 1-micron in-line PTFE filter into a distillation flaskand is then concentrated to ~12L under vacuum (internal temperature <40°C). Heptane is added and thedistillation is continued under vacuum at 40°-55°C until the final volume is 40L. The solution is cooledto 35°-37"C , seeded (-0.5%, 30gms) and then aged for 30min to allow for a full seed bed to grow. Theslurry is cooled to 10°C over 2-3 hrs. The slurry is then filtered, washed with 5°C heptane (18L), andallowed to dry fully on the filter pot using a vacuum/nitrogen sweep overnight. The dried solid isobtained with >99.9ee%. The amide can be recrystallized from straight heptane if the optical purity isnot sufficient.

References:

WO2006/14357,2006,A1 Location in patent:Page/Page column 50-51