Ethyl Acetate → 1,1-dimethylethyl (2S)-2-methyl-4-{[2-methyl-4-(trifluoromethyl)phenyl]sulfonyl}-1-piperazinecarboxylate

HRID 418293Notes

Reaction equation

Br[C:2]1[CH:7]=[C:6]([C:8]([F:11])([F:10])[F:9])[CH:5]=[CH:4][C:3]=1[S:12]([N:15]1[CH2:20][CH2:19][N:18]([C:21]([O:23][C:24]([CH3:27])([CH3:26])[CH3:25])=[O:22])[C@@H:17]([CH3:28])[CH2:16]1)(=[O:14])=[O:13].[C:29](=O)([O-])[O-].[K+].[K+].CB1OB(C)OB(C)O1.CCOC(C)=O>O1CCOCC1.C1C=CC([P]([Pd]([P](C2C=CC=CC=2)(C2C=CC=CC=2)C2C=CC=CC=2)([P](C2C=CC=CC=2)(C2C=CC=CC=2)C2C=CC=CC=2)[P](C2C=CC=CC=2)(C2C=CC=CC=2)C2C=CC=CC=2)(C2C=CC=CC=2)C2C=CC=CC=2)=CC=1>[CH3:28][C@H:17]1[CH2:16][N:15]([S:12]([C:3]2[CH:4]=[CH:5][C:6]([C:8]([F:11])([F:10])[F:9])=[CH:7][C:2]=2[CH3:29])(=[O:14])=[O:13])[CH2:20][CH2:19][N:18]1[C:21]([O:23][C:24]([CH3:27])([CH3:26])[CH3:25])=[O:22]

Participants

Conditions

Temperature: 100 °C

Procedure

A solution of 1,1-dimethylethyl(2S)-4-{[2-bromo-4-(trifluoromethyl)phenyl]sulfonyl}-2-methyl-1-piperazinecarboxylate (1.00 g, 2.05 mmol) (may be prepared as described in Description 26), potassium carbonate (0.737 g, 5.34 mmol) in 1,4-dioxane (43 ml) were stirred for 5 min then trimethylboroxin (0.743 ml, 5.34 mmol) and Pd(Ph3P)4 (0.403 g, 0.349 mmol) were added and the reaction mixture heated at 100° C. overnight. EtOAc (100 ml) was added then the mixture washed aqueous sodium bicarbonate (100 ml), water (100 ml) and concentrated under vacuum. Flash chromatography (silica; linear gradient (0-20%) EtOAc in isohexane) gave 1,1-dimethylethyl(2S)-2-methyl-4-{[2-methyl-4-(trifluoromethyl)phenyl]sulfonyl}-1-piperazinecarboxylate (0.785 g).

Workup

washthe mixture washed aqueous sodium bicarbonate (100 ml), water (100 ml)
concentrationconcentrated under vacuum

Sources & evidence

ORD record: ord-f44c7f4e65224750bf083e0d332abc86
Source dataset: uspto-grants-2012_01
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US08093249B2

Reaction notes

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