Cesium carbonate → 3-(Tert-butoxycarbonylamino-methyl)-5-methyl-hexanoic acid 1-isobutyryloxy-ethyl ester

HRID 1361046Notes

Reaction equation

HRID 1361046 reaction equation
C(=O)([O-])[O-].[Cs+].[Cs+].C(O[C:10]([O:12][CH:13]([O:15][C:16](=[O:32])[CH2:17][CH:18]([CH2:23][NH:24][C:25]([O:27][C:28]([CH3:31])([CH3:30])[CH3:29])=[O:26])[CH2:19][CH:20]([CH3:22])[CH3:21])[CH3:14])=[O:11])C.IC(O[C:37](=O)[CH:38](C)[CH3:39])C>CO.CC#N>[C:10]([O:12][CH:13]([O:15][C:16](=[O:32])[CH2:17][CH:18]([CH2:23][NH:24][C:25]([O:27][C:28]([CH3:29])([CH3:30])[CH3:31])=[O:26])[CH2:19][CH:20]([CH3:21])[CH3:22])[CH3:14])(=[O:11])[CH:38]([CH3:39])[CH3:37]

Participants

6

Reactant 3

HCID 10796Cesium carbonateHCID 14633820Propanoic acid, 2-methyl-, 1-iodoethyl esterHCID 723692293-(Tert-butoxycarbonylamino-methyl)-5-methyl-hexanoic acid 1-ethyloxycarbonyloxy-ethyl ester

Product 1

HCID 723692273-(Tert-butoxycarbonylamino-methyl)-5-methyl-hexanoic acid 1-isobutyryloxy-ethyl esterYield 27.2%

Reagents, catalysts & solvents 2

HCID 887MethanolSolventHCID 6342AcetonitrileSolvent2×

Procedure

Cesium carbonate (0.365 g, 1.12 mmol) was dissolved in methanol (5 mL) and S-form of compound 4 (0.500 g, 1.28 mmol) was added. The solution was stirred for 4 hours at room temperature and concentrated to dryness. The residue was diluted with CH3CN (7.5 mL), and compound 14 (0.945 g, 3.56 mmol) and CH3CN (5 mL) were then added. After stirring overnight at room temperature, the reaction solution was filtered and concentrated to give 1 g of the crude product, which was then purified by chromatography on a column of silica gel (70-230 mesh, elution: EA/Hexane=1:4). Compound 3-(tert-butoxycarbonylamino-methyl)-5-methyl-hexanoic acid 1-isobutyryloxy-ethyl ester 15 (0.13 g) was obtained with 27% yield. 1HNMR (CDCl3, 500 MHz) δ0.87-0.92 (m, 6H), 1.10-1.21 (m, 2H), 1.55 (d, J=5 Hz, 6H), 1.44 (s, 9H), 1.48 (d, J=5.5 Hz, 3H), 1.52-1.59 (m, 2H), 2.06-2.12 (m, 1H), 2.28-2.35 (m, 2H), 2.49-2.57 (m, 1H), 2.93-3.06 (m, 1H), 3.12-3.22 (m, 1H), 4.62-4.73 (m, 1H), 6.84 (q, J=5.5 Hz, 1H).

Workup

  1. concentrationconcentrated to dryness
  2. additionwere then added
  3. stirringAfter stirring overnight at room temperature
  4. filtrationthe reaction solution was filtered
  5. concentrationconcentrated
  6. customto give 1 g of the crude product, which
  7. customwas then purified by chromatography on a column of silica gel (70-230 mesh, elution: EA/Hexane=1:4)

Sources & evidence

ORD record
ord-e32920b6c0f040e7900d315776f2d569
Source dataset
uspto-grants-2011_02
Patent number
US07879906B2

Reaction notes

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