What are the main USES of piperidine?

1: used as an analytical reagent
2: used as a condensation agent and solvent in organic synthesis
3: edible spices
4: hexahydropyridine, also known as piperidine, is the intermediate of the plant growth regulator mepionium
5. Piperidine, also known as hexahydropyridine, is the intermediate between benzodiazepine, an antimicrobial agent, and mepionium, a plant growth regulator
6: used as intermediate of synthetic drugs, raw material of rubber accelerator and curing agent of epoxy resin
7: piperidine is used in the manufacture of local anesthetics, painkillers, fungicides, wetting agents, epoxy curing agents, rubber curing agents, etc