反応 #1077769

反応方程式

artelinic acid

1-hydroxybenzotriazole

→

artelinate

収率 119.5%

溶媒

CHCl3

反応条件

後処理

1. 1
   その他the solvent was removed in vacuo
2. 2
   workup.DISSOLUTIONThe gum was dissolved in CH2Cl2 (˜30 ml) under an argon atmosphere and to the solution
3. 3
   温度to reflux overnight under an argon atmosphere
4. 4
   濃縮The cloudy mixture was concentrated to dryness and to the residue
5. 5
   workup.ADDITIONwas added CH2Cl2 (˜5 ml)
6. 6
   workup.ADDITIONTo the slightly turbid solution was added EtOH (˜100 ml)
7. 7
   その他a white solid was obtained
8. 8
   温度upon cooling in an ice bath for ˜3 h
9. 9
   その他Repeating the purification

実験手順

8 arm PEG (20 Kda) (2.0 g, ˜0.10 mmol) was dissolved in CHCl3 (300 ml) and the solvent was removed in vacuo. The gum was dissolved in CH2Cl2 (˜30 ml) under an argon atmosphere and to the solution was added artelinic acid (0.85 g, 2.00 mmol), 1-hydroxybenzotriazole (0.085 g, 0.63 mmol) and 4-(dimethylamino)pyridine (cat.). The mixture was allowed to reflux overnight under an argon atmosphere. The cloudy mixture was concentrated to dryness and to the residue was added CH2Cl2 (˜5 ml). To the slightly turbid solution was added EtOH (˜100 ml) and a white solid was obtained upon cooling in an ice bath for ˜3 h. Repeating the purification afforded pure 8 arm PEG (20 Kda) artelinate (1.00 g) as a water-soluble white solid. 1H NMR (CDCl3, 300 MHz) indicated a near quantitative conversion. HPLC (C-4 reversed-phase) indicated a mixture of products arising from different degrees of substitution. Partial 1H NMR data (CDCl3, 300 MHz): δ 0.94 (s, 24H, C9—CH3), 0.95 (s, 24H, C6—CH3), 1.44 (s, 24H, C3—CH3), 2.68 (m, 8H, H-9), 3.63 (bs, 1818H, PEG backbone), 4.45 (t, 16H, J 4.4 Hz, PEG—OCH2CH2O—COAr), 4.56 (d, 8H, J 13.1 Hz, OCHAHB—Ar), 4.91-4.96 (m, 16H, H-10 overlapped with OCHAHB—Ar), 5.44 (s, 7.5H, H-12), 7.37 (d, 8H, J 7.8 Hz, Ar), 8.01 (d, 8H, Ar).

出典