Reference of 25662-28-6, As we all know, there are many different methods for the synthesis of a compound, and people can choose the synthesis method that suits their own laboratory according to the actual situation. 25662-28-6 name is Methyl 1-cyclopentene-1-carboxylate, This compound is widely used in many fields, so it is necessary to find a new synthetic route. The downstream synthesis method of this compound is introduced below.
Experimental Procedures-Part 1 :; Step 1 – Oxidation of Carboxymethylcyclopentene:; Procedure:; To a cooled (00C) 2 L round bottom flask with a magnetic stir bar and internal temperature probe was added acetic anhydride (615 g, 570 mL, 6.02 mol). Chromium trioxide (214 g, 2.14 mol) was added in portions while maintaining constant stirring and to control the exotherm. The resulting blood red solution was stirred to dissolve the chromium trioxide until the temperature had cooled to 20 0C. A 5 L three-neck flask was fitted with an addition funnel, overhead stirring mechanism, nitrogen inlet and internal temperature probe and charged with 4 (100 g, 101 mL, 0.793 mol) in 1.4 L CH2Cl2. The oxidizing solution of chromium trioxide and acetic anhydride was charged to the addition funnel and added dropwise to the reaction mixture, maintaining the internal temperature between 10 and 14 0C. The initially yellow solution became dark after the first few drops of oxidizer were added.The reaction was worked up in two equally-sized batches due to limitations on vessel size in the laboratory. Each batch was treated exactly the same way, as follows: The dark, homogeneous solution was poured carefully into a 4 L beaker with an overhead stirring mechanism. The reaction flask was rinsed with 250 mL CH2Cl2. 500 mL H2O was added followed by 10 g NaHCC?3 which resulted in gas evolution. Additional NaHCC>3 (830 g, 10 mol) was added in portions while maintaining 500 rpm stir rate in the viscous mixture. The resulting dark green suspension was diluted with 1 L H2O and filtered through a 3 L fritted funnel containing a 1 cm pad of solka floe. The biphasic solution was extracted with CH2CI2 (3×1 L) and the combined organics dried using MgSO.), then filtered and the resulting solution was concentrated in vacuo to afford a pale green oil. Distillation through a 30 cm Vigreux column followed by recrystallization from MTBE:hexane (1:10, 55 mL total) provided 38.4 g of 5 as a white crystalline solid (35%).ted yield
At the same time, in my other blogs, there are other synthetic methods of this type of compound, Methyl 1-cyclopentene-1-carboxylate, and friends who are interested can also refer to it.
Reference:
Patent; MERCK & CO., INC.; BANYU PHARMACEUTICAL CO., LTD.; WO2008/21029; (2008); A2;,
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