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ChemicalBook CAS DataBase List Ethyl (2R,4R)-4-methyl-2-piperidinecarboxylate
74892-82-3

Ethyl (2R,4R)-4-methyl-2-piperidinecarboxylate synthesis

7synthesis methods
-

Yield:74892-82-3 345 g

Reaction Conditions:

with palladium 10% on activated carbon;hydrogen;iron(II) oxalate;acetic acid in ethanol at 30; under 3750.38 Torr; for 4 h;Autoclave;Reagent/catalyst;

Steps:

1.2 two,(2R, 4R) -4-methylpiperidine-2-carboxylate Preparation

The crude product (618 g) obtained in the previous step and ethanol (2 mL) were charged into a 5 L autoclave,Additional acetic acid (45 g), palladium on carbon catalyst (10% palladium loading, 15 g), 3 g iron oxalate,Access to H2, at 30 , 0.5MPa reaction 4h,filter,Catalyst recovery.The filtrate was concentrated under reduced pressure and added with ethyl acetate (1 L)Washed sequentially with saturated sodium carbonate solution (250 mL × 2), saturated brine (250 mL × 2)Dried over anhydrous sodium sulfate, filtered,The filtrate was concentrated under reduced pressure,Have a pale yellow liquid product.The resulting crude product was purified by distillation,Collected 89 ~ 90 / 10mmHg fractions,345 g of ethyl (2R, 4R) -4-methyl-2-piperidinecarboxylate was obtained in a yield of 91%.Optical rotation: (c = 5, EtOH)The total process yield above: 82.45%.Liquid chromatography determination:The (2R, 4R) -4-methyl-2-piperidinecarboxylic acid ethyl ester content was 99.3%.

References:

CN107043347,2017,A Location in patent:Paragraph 0029; 0030; 0031; 0032-0034; 0039-0044; 0046; 0048

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