Reaktion #65588

Reaktionsgleichung

2-cyclododecylethyl isocyanate

tetronic acid

triethylamine

KBr

→

4-Hydroxy-2-oxo-2.5-dihydro-furan-3-carboxylic acid-2-cyclododecyl-ethylamide

Lösungsmittel

chloroform

Reaktionsbedingungen

Aufarbeitung

1. 1
   SonstigeThe reaction mixture was quenched with 1N HCl
2. 2
   Sonstigethe layers separated
3. 3
   Trocknenthe organic fraction dried over MgSO4
4. 4
   Filtrationfiltered
5. 5
   Sonstigechromatographed
6. 6
   Sonstigeto give a yellow solid

Vorschrift

To a dry flask containing 40 mL of chloroform was added 1.87 g (18.7 mmol) of tetronic acid, 2.29 g (18.7 mmol) of 4-N,N-dimethylaminopyridine, 2.6 mL (18.7 mmol) of triethylamine followed by 4.4 g (18.7 mmol) of 2-cyclododecylethyl isocyanate. The reaction mixture was allowed to stir overnight at room temperature, after which time a small amount of starting materials was still evident by TLC. The reaction mixture was quenched with 1N HCl, the layers separated, the organic fraction dried over MgSO4, filtered, and stripped of solvent. The residue was flash chromatographed using acidic silica gel eluting with 25% EtOAc/hexane to give a yellow solid. M.P. 135°-137° C. Spectral data follow: 1H NMR (DMSO-d6) δ 8.05 (bs, 1H), 4.6 (s, 2H), 4.2 (bs, 10H), 3.25 (t, 2H), 2.5 (s, 3H), 1.2-1.4 (bm, >20H); IR (KBr) 3340, 2920, 2850 (C--H), 1750, 1650 cm-1 (C=0);

Quelle