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ChemicalBook CAS DataBase List METHYL 4-BOC-PIPERAZINE-2-CARBOXYLATE
129799-08-2

METHYL 4-BOC-PIPERAZINE-2-CARBOXYLATE synthesis

12synthesis methods
-

Yield:129799-08-2 85.2%

Reaction Conditions:

Stage #1:N,N'-di-tert-butyloxycarbonylpiperazine-2-carboxylic acid with pyridine;oxalyl dichloride in tetrahydrofuran at 10 - 30;
Stage #2:methanol in tetrahydrofuran at 40 - 50;Reagent/catalyst;

Steps:

3; 4 Synthesis of methyl 4-Boc piperazine-2-carboxylate
In a 1.0L reaction flask, add 1,4-bisBoc piperazine-2-carboxylic acid (20g), add anhydrous THF (200mL), stir well, add pyridine (7.2g), reduce the temperature to 0-10, add dropwise a solution of oxalyl chloride (9.2g) in THF (100mL), control the temperature not to exceed 10, stir at 20-30 for 2-3h, and finally add methanol ( 200mL) continue the reaction at 40-50°C for 2-3h. After the reaction is complete, the reaction solution is concentrated under reduced pressure to remove methanol and pyridine, and ethyl acetate is added to dissolve it. The pH value is adjusted to 9-10 with saturated sodium carbonate aqueous solution. The phases were continuously extracted with EA, the organic phases were combined, dried over anhydrous sodium sulfate, concentrated under reduced pressure, and column chromatography to obtain the target product (12.6 g, molar yield: 85.2%).

References:

CN112321538, 2021, A Location in patent:Paragraph 0026-0031

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