反応 #1504

反応方程式

L-lactic acid

Acetic anhydride

DL-2-Hydroxycaproic acid

→

lactic acid

hydroxycaproic acid

溶媒

water

water

反応条件

後処理

1. 1
   その他0.043 moles) were placed in a reaction flask
2. 2
   その他equipped with a distillation head and mechanical stirrer
3. 3
   その他was removed
4. 4
   温度by heating at 80° C. for 14 hours
5. 5
   workup.DISTILLATIONExcess acetic anhydride and acetic acid were distilled off under low vacuum
6. 6
   workup.ADDITIONTetrahydrofuran/water (15 mL of 85/15; v/v) was added
7. 7
   温度heating at 60° C. for 0.5 hours
8. 8
   その他The bulk of the solvent was removed by vacuum distillation on a rotary evaporator
9. 9
   workup.DISSOLUTIONThe resulting crude product was dissolved in chloroform (20 mL)
10. 10
    洗浄The chloroform solution was washed twice with millipore water (5 mL)
11. 11
    乾燥dried with MgSO4
12. 12
    ろ過The mixture was filtered through a "d" fritted glass funnel
13. 13
    workup.DISTILLATIONthe solvent distilled from the oligomer by rotary evaporation
14. 14
    その他Final traces of solvents were removed under high vacuum (0.4 mmHg) on a Kugelrohr apparatus at 120° C.

実験手順

DL-2-Hydroxycaproic acid (1.00 g, 0.0076 moles), and L-lactic acid (4.5 g of a nominally 85% solution in water; 0.043 moles) were placed in a reaction flask equipped with a distillation head and mechanical stirrer. The flask was heated at 110° C. for 6 hours under low vacuum (aspirator) while water was removed. The temperature was then raised to 140° C. for 6 hours. Acetic anhydride (5.16 g; 0.0506 moles) was added to the oligomer, followed by heating at 80° C. for 14 hours. Excess acetic anhydride and acetic acid were distilled off under low vacuum. Tetrahydrofuran/water (15 mL of 85/15; v/v) was added with stirring and heating at 60° C. for 0.5 hours. The bulk of the solvent was removed by vacuum distillation on a rotary evaporator. The resulting crude product was dissolved in chloroform (20 mL). The chloroform solution was washed twice with millipore water (5 mL) and then dried with MgSO4. The mixture was filtered through a "d" fritted glass funnel and the solvent distilled from the oligomer by rotary evaporation. Final traces of solvents were removed under high vacuum (0.4 mmHg) on a Kugelrohr apparatus at 120° C. to provide acetyl-oligo(D,L-2-hydroxycaproic-co-L-Lactic acid) with n=7.5 for lactic acid and 1.4 for hydroxycaproic acid, MN =763, and MW =1044.

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