2,2,6,6-Tetramethyl-4-piperidone, hydrochloride 2,2,6,6-Tetramethylpiperidin-4-one hydrochloride 33973-59-0 4-Piperidinone, 2,2,6,6-tetramethyl-, hydrochloride 826-36-8 EINECS 251-769-6