Yield: 98.3%

Reaction Conditions:

with 5%-palladium/activated carbon;hydrogen in methanol at 40 - 45; under 1500.15 - 2250.23 Torr; for 4 h;Autoclave;

Steps:

1 Example 1: Preparation of methyl piperidin-4-one-3-carboxylate
Into a 500-ml stainless steel autoclave, 300 g of methanol, 49.5 g (0.2 mol) of N-benzylpiperidine-4-one-3-carboxylic acid methyl ester, 0.9 g of 5% palladium-carbon catalyst, and nitrogen substitution for three times were passed in. Hydrogen, keeping the system pressure at 0.2-0.3 MPa, and reacting at 40-45 ° C for 4 hours. Replaced with nitrogen three times, filtered to remove palladium on carbon, washed the filter cake twice with 30 g of methanol each time, and combined the filtrates. The solvent was distilled off to recover the solvent, and 30.9 g of piperidin-4-one-3-carboxylic acid methyl ester was obtained in a yield of 98.3% and a gas phase purity of 99.7%.

References:

Xin Fa Pharmaceutical Co., Ltd.;Lv Qiangsan;Qi Yuxin;Wang Quanlong;Zhang Mingfeng;Ju Lizhu CN110483388, 2019, A Location in patent:Paragraph 0060-0061