tert-Butanol → Docos-21-ynoic Acid. Tert.-Butyl Ester

HRID 2399983Notes

Reaction equation

HRID 2399983 reaction equation
[C:1]([OH:24])(=[O:23])[CH2:2][CH2:3][CH2:4][CH2:5][CH2:6][CH2:7][CH2:8][CH2:9][CH2:10][CH2:11][CH2:12][CH2:13][CH2:14][CH2:15][CH2:16][CH2:17][CH2:18][CH2:19][CH2:20][C:21]#[CH:22].CN(C1C=CC=CN=1)C.[C:34](O)([CH3:37])([CH3:36])[CH3:35].C1(N=C=NC2CCCCC2)CCCCC1>C(Cl)(Cl)Cl.C(O)C>[C:1]([O:24][C:34]([CH3:37])([CH3:36])[CH3:35])(=[O:23])[CH2:2][CH2:3][CH2:4][CH2:5][CH2:6][CH2:7][CH2:8][CH2:9][CH2:10][CH2:11][CH2:12][CH2:13][CH2:14][CH2:15][CH2:16][CH2:17][CH2:18][CH2:19][CH2:20][C:21]#[CH:22]

Participants

7

Reactant 4

HCID 6386tert-ButanolHCID 10868DicyclohexylcarbodiimideHCID 218852-DimethylaminopyridineHCID 54502951Docos-21-ynoic Acid

Product 1

HCID 86749000Docos-21-ynoic Acid. Tert.-Butyl EsterYield 86.5%

Reagents, catalysts & solvents 2

HCID 702EthanolSolventHCID 6212ChloroformSolvent

Procedure

The acid (32) (6.4 g, 0.019 mol) was dissolved in dry, ethanol free, chloroform (120 ml) at room temperature under nitrogen and sequentially treated with dimethylaminopyridine (2.55 g, 0.0209 mol), tert butanol (14.09 g, 0.19 mol), dimethylaminopyridine-trifluoroacetic acid complex (4.94 g, 0.0209 mol) and dicyclohexylcarbodiimide (4.31 g, 0.0209 mol). The resulting solution was stirred at room temperature overnight then filtered, the organic layer washed with 5% acetic acid in water, then dried (MgSO4), filtered and evaporated. The residue was purified by chromatography on silica gel (50 g). Elution with 10% ether in petrol gave the title compound (33) as white crystals (6.45 g, 86%) mp 44°-45° C.

Workup

  1. customin dry
  2. filtrationthen filtered
  3. washthe organic layer washed with 5% acetic acid in water
  4. dry with materialdried (MgSO4)
  5. filtrationfiltered
  6. customevaporated
  7. customThe residue was purified by chromatography on silica gel (50 g)
  8. washElution with 10% ether in petrol

Sources & evidence

ORD record
ord-855eab96cae946449702111060dc039e
Source dataset
uspto-grants-1995_09
Patent number
US05451691

Reaction notes

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