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ChemicalBook CAS DataBase List DL-Lactide
95-96-5

DL-Lactide synthesis

9synthesis methods
-

Yield:95-96-5 73%

Reaction Conditions:

with ytterbium(III) triflate in 5,5-dimethyl-1,3-cyclohexadiene at 180; for 14 h;Reagent/catalyst;

Steps:

1 Example 1
Example 1 [0057] A 100 mL round-bottom flask, a dean stark, and a cooling pipe were used. The dean stark is disposed at the center for an azeotropic distillation, and the cooling pipe is connected to an upper portion of the dean stark. [0058] To the round-bottom flask, 100 mg (1.1101 mmol) of ammonium lactate and 40 mL of xylene were added to obtain a mixture. Subsequently, 6.88 mg (0.0111 mmol) of ytterbium triplate was added to the mixture as a catalyst. The mixture was stirred. The flask was heated using a heating plate for 14 hours, and then lactate, lactide produced by the catalytic reaction, lactate by the azeotropic distillation, and other by-products were transferred to a separation funnel with the solvent (xylene). The amount of the catalyst, ytterbium triplate (Yb(OTf)3), was about 1 mol %. [0059] The solvent, lactide, and impurities obtained from the separation funnel were mixed with ethyl acetate and water to separate the impurities. 40 mL of ethyl acetate and 40 mL of water were added thereto based on the total volume of the solvent, lactide, and impurities. The ethyl acetate layer was subjected to an extraction and the extract was transferred to a rotary evaporator. The ethyl acetate and the solvent (xylene) were evaporated to obtain 58.4 mg (0.4052 mmol) of lactide (73%). 1H NMR (400 MHz, CDCl3) δ 5.03 (q, 2H), δ 1.68 (d, 6H), 13C NMR (100 mHz) δ 167.4, δ 72.5, δ 15.8, mp 97° C.

References:

HYUNDAI MOTOR COMPANY;Hong, Chae Hwan;Kim, Si Hwan;Seo, Jiyoun;Han, Do Suck US2013/267716, 2013, A1 Location in patent:Paragraph 0057-0059

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