(S)-isopropyl 2-(5-bromo-2,6-dimethyl-4-(4-phenylpiperidin-1-yl)pyridin-3-yl)-2-hydroxyacetate → (S)-isopropyl 2-(5-bromo-2,6-dimethyl-4-(4-phenylpiperidin-1-yl)pyridin-3-yl)-2-(tert-butoxy)acetate

HRID 718388Notes

Reaction equation

HRID 718388 reaction equation
[Br:1][C:2]1[C:3]([N:18]2[CH2:23][CH2:22][CH:21]([C:24]3[CH:29]=[CH:28][CH:27]=[CH:26][CH:25]=3)[CH2:20][CH2:19]2)=[C:4]([C@H:10]([OH:17])[C:11]([O:13][CH:14]([CH3:16])[CH3:15])=[O:12])[C:5]([CH3:9])=[N:6][C:7]=1[CH3:8]>C(Cl)Cl>[Br:1][C:2]1[C:3]([N:18]2[CH2:23][CH2:22][CH:21]([C:24]3[CH:29]=[CH:28][CH:27]=[CH:26][CH:25]=3)[CH2:20][CH2:19]2)=[C:4]([C@H:10]([O:17][C:4]([CH3:10])([CH3:5])[CH3:3])[C:11]([O:13][CH:14]([CH3:16])[CH3:15])=[O:12])[C:5]([CH3:9])=[N:6][C:7]=1[CH3:8]

Participants

3

Reactant 1

HCID 118307826(S)-isopropyl 2-(5-bromo-2,6-dimethyl-4-(4-phenylpiperidin-1-yl)pyridin-3-yl)-2-hydroxyacetate

Product 1

HCID 118307820(S)-isopropyl 2-(5-bromo-2,6-dimethyl-4-(4-phenylpiperidin-1-yl)pyridin-3-yl)-2-(tert-butoxy)acetateYield 249.9%

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent2×

Procedure

The isobutylene gas was bubbled into a nitrogen purged, cooled (0° C.) solution of (S)-isopropyl 2-(5-bromo-2,6-dimethyl-4-(4-phenylpiperidin-1-yl)pyridin-3-yl)-2-hydroxyacetate (1.95 g, 1.5 mmol) and 0.6 mL of 70% HClO4 in DCM (25 mL) for 20 min. The reaction mixture was allowed to warm to rt and stirred for 18 h in a pressure sealed vessel, diluted with DCM, washed with 1M Na2CO3 solution, and dried over MgSO4. The crude product was charged (DCM) to a 80 g ISCO silica gel cartridge and gradient elution (5-50% EtOAc/hexanes) using an Isolera chromatography station gave (S)-isopropyl 2-(5-bromo-2,6-dimethyl-4-(4-phenylpiperidin-1-yl)pyridin-3-yl)-2-(tert-butoxy)acetate 970 mg (44.4%) as a mixture of diastereomers. 1H NMR (500 MHz, DMSO-d6) δ 7.36-7.33 (m, 2H), 7.29-7.28 (m, 2H), 7.23-7.20 (m, 1H), 6.26 (s, 1H), 4.95-4.90 (m, 1H), 3.98 (br. s, 1H), 3.41 (br. s, 1H), 3.12 (br. s, 1H), 2.98 (br. s, 1H), 2.71 (br. s, 1H), 2.51 (s, 3H), 2.44 (s, 3H), 1.93 (br. s, 1H), 1.82-1.75 (m, 3H), 1.18 (s, 9H), 1.15 (d, J=6.2 Hz, 3H), 1.07 (d, J=5.9 Hz, 3H). UPLC (M+H)=519.2.

Workup

  1. customThe isobutylene gas was bubbled into a nitrogen
  2. custompurged
  3. customsealed vessel
  4. washwashed with 1M Na2CO3 solution
  5. dry with materialdried over MgSO4
  6. additionThe crude product was charged (DCM)
  7. washto a 80 g ISCO silica gel cartridge and gradient elution (5-50% EtOAc/hexanes)

Sources & evidence

ORD record
ord-be3089bf15d4473da5323b0bb36a1635
Source dataset
uspto-grants-2015_11
Patent number
US09193720B2

Reaction notes

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