32559-18-5

Methyl Pipecolinate Hydrochloride is a reactant for synthesis of a pipecolic linker and antiviral agents.

Methyl pipecolinate hydrochloride is a hydrochloride salt of methyl piperidine-2-carboxylate (methyl pipecolinate). The kinetics of the enzymatic separation of enantiomeric forms of methyl pipecolinate using Candida antarctica Lipase A (CAL-A) has been reported. Its role as catalyst for the standard Diels-Alder reaction has been examined.

Synthesis of methylpiperidine-2-carboxylic acid hydrochloride: methanol (1300 mL) was added to a 3000 mL three-necked round bottom flask. The reaction system was cooled to -30°C. Sulfoxide chloride (280 mL) was added slowly and dropwise under stirring conditions while keeping the temperature at -30 °C. Subsequently, piperidine-2-carboxylic acid (100 g, added in batches) was added to the reaction system and the mixture was cooled to 0 °C. The reaction was continuously stirred for 15 h at room temperature. The progress of the reaction was monitored by thin layer chromatography (TLC, the unfolding agent was methanol and a few drops of ammonia were added). After completion of the reaction, the reaction mixture was concentrated under vacuum using a rotary evaporator. Toluene (100 mL) was added to the concentrate and kept under reflux conditions. The mixture was again concentrated under vacuum using a rotary evaporator. This toluene addition and concentration step was repeated twice. The final product was 137 g (98% yield) of methylpiperidine-2-carboxylic acid hydrochloride as a white solid.

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