Phthalimide → 3-Phthalimidocholestane

HRID 1420545Notes

Reaction equation

HRID 1420545 reaction equation
[CH3:1][C@@H:2]([C@@H:9]1[C@@:13]2([CH3:28])[CH2:14][CH2:15][CH2:16]/[C:17](=[CH:18]\[CH:19]=[C:20]3\[CH2:21][C@@H:22](O)[CH2:23][CH2:24][C:25]\3=[CH2:26])/[C@@H:12]2[CH2:11][CH2:10]1)[CH2:3][CH2:4][CH2:5][CH:6]([CH3:8])[CH3:7].[C:29]1(=[O:39])[NH:33][C:32](=[O:34])[C:31]2=[CH:35][CH:36]=[CH:37][CH:38]=[C:30]12.C1(P(C2C=CC=CC=2)C2C=CC=CC=2)C=CC=CC=1.CCOC(/N=N/C(OCC)=O)=O>C1COCC1>[C:29]1(=[O:39])[N:33]([CH:22]2[CH2:23][CH2:24][C@@:25]3([CH3:26])[CH:20]([CH2:19][CH2:18][C@@H:17]4[C@@H:16]3[CH2:15][CH2:14][C@@:13]3([CH3:28])[C@H:12]4[CH2:11][CH2:10][C@@H:9]3[C@H:2]([CH3:1])[CH2:3][CH2:4][CH2:5][CH:6]([CH3:8])[CH3:7])[CH2:21]2)[C:32](=[O:34])[C:31]2=[CH:35][CH:36]=[CH:37][CH:38]=[C:30]12

Participants

6

Reactant 4

HCID 6809PhthalimideHCID 11776TriphenylphosphineHCID 5280795Vitamin D3HCID 5462977Diethyl azodicarboxylate

Product 1

HCID 543667153-PhthalimidocholestaneYield 81.3%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent

Procedure

To a solution of dihydrocholesterol (5.0 g, 12.9 mmol, Aldrich), phthalimide (2.0 g, 13.6 mmol, Aldrich), and triphenylphosphine (3.8 g, 13.6 mmol, Aldrich) in THF (20 ml, Aldrich) stirred at 0° C. under a nitrogen atmosphere was added dropwise diethylazodicarboxylate (2.3 ml, 14.5 mmol, Aldrich). Upon the completion of addition the reaction mixture was allowed to warm to ambient temperature and stirred overnight. The reaction mixture was concentrated in vacuo to a residue. This residue was dissolved in 50 ml hexane/ethyl acetate 95/5 and a precipitate formed. The mixture was filtered. The filtrate was concentrated to dryness in vacuo, dissolved in 25 ml of hexane/ethyl acetate 95/5 and chromatographed on 200 g silica gel (eluent 2 L hexane/ethyl acetate 95/5 then 1 L hexane/ethyl acetate 90/10). A 76% yield of the desired 3-phthalimidocholestane (5.43 g) was obtained.

Workup

  1. additionUpon the completion of addition the reaction mixture
  2. concentrationThe reaction mixture was concentrated in vacuo to a residue
  3. dissolutionThis residue was dissolved in 50 ml hexane/ethyl acetate 95/5
  4. customa precipitate formed
  5. filtrationThe mixture was filtered
  6. concentrationThe filtrate was concentrated to dryness in vacuo
  7. dissolutiondissolved in 25 ml of hexane/ethyl acetate 95/5
  8. customchromatographed on 200 g silica gel (eluent 2 L hexane/ethyl acetate 95/5

Sources & evidence

ORD record
ord-bb647e4090a1452a92b8382a7ed11639
Source dataset
uspto-grants-2000_06
Patent number
US06071890

Reaction notes

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