(2S)-isopropyl 2-(5-bromo-4-(3-cyclopropylpyrrolidin-1-yl)-2,6-dimethylpyridin-3-yl)-2-hydroxyacetate → (2S)-isopropyl 2-(5-bromo-4-(3-cyclopropylpyrrolidin-1-yl)-2,6-dimethylpyridin-3-yl)-2-(tert-butoxy)acetate

HRID 718375Notes

Reaction equation

HRID 718375 reaction equation
[Br:1][C:2]1[C:3]([N:18]2[CH2:22][CH2:21][CH:20]([CH:23]3[CH2:25][CH2:24]3)[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[CH2:22][CH2:21][CH:20]([CH:23]3[CH2:25][CH2:24]3)[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 118307798(2S)-isopropyl 2-(5-bromo-4-(3-cyclopropylpyrrolidin-1-yl)-2,6-dimethylpyridin-3-yl)-2-hydroxyacetate

Product 1

HCID 118307883(2S)-isopropyl 2-(5-bromo-4-(3-cyclopropylpyrrolidin-1-yl)-2,6-dimethylpyridin-3-yl)-2-(tert-butoxy)acetateYield 88.2%

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent2×

Procedure

The isobutylene gas was bubbled into a nitrogen purged, cooled (0° C.) solution of (2S)-isopropyl 2-(5-bromo-4-(3-cyclopropylpyrrolidin-1-yl)-2,6-dimethylpyridin-3-yl)-2-hydroxyacetate (525 mg, 1.28 mmol) and 0.15 mL of 70% HClO4 in DCM (10 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 40 g ISCO silica gel cartridge and gradient elution (5-35% EtOAc/hexanes) using an Isolera chromatography station gave (2S)-isopropyl 2-(5-bromo-4-(3-cyclopropylpyrrolidin-1-yl)-2,6-dimethylpyridin-3-yl)-2-(tert-butoxy)acetate 264 mg (44%) as a mixture of diastereomers. 1H NMR (500 MHz, DMSO-d6) δ 5.92/5.87 (s, 1H), 4.91-4.85 (m, 1H), 3.47/3.27 (br. s, 1H), 3.17-3.10 (m, 2H), 2.94-2.91 (m, 1H), 2.52 (s, 3H), 2.41 (s, 3H), 2.16/2.07 (br. s., 1H), 1.86-1.77 (m, 2H), 1.15-1.12 (m, 12H), 1.06-1.03 (m, 3H), 0.92-0.87/0.80-0.78 (m, 1H), 0.47-0.37 (m, 2H), 0.19-0.10 (m, 2H). UPLC (M+H)=469.3.

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 40 g ISCO silica gel cartridge and gradient elution (5-35% EtOAc/hexanes)

Sources & evidence

ORD record
ord-1b2a4d833b724c5899140e427f4ca4c6
Source dataset
uspto-grants-2015_11
Patent number
US09193720B2

Reaction notes

Loading…