2,2,6,6-Tetramethylpiperidine or TMP or HTMP is an organic compound of the amine class. In appearance, it is a colorless liquid and has a "fishy", amine-like odor. This amine is used in chemistry as a hindered base (hindered amine) because it can dissolve in organic solvents unlike inorganic bases such as potassium hydroxide. There are many ways to synthesise TMP. One method starts with a conjugate addition reaction of ammonia to phorone. The intermediate triacetone amine is then reduced in a Wolff-Kishner reaction. TMP is the starting material for an even stronger base lithium tetramethylpiperidide and the radical species TEMPO. Another non-nucleophilic base is N,N-diisopropylethylamine. Tefenperate is made from 2,2,6,6-Tetramethylpiperidine precursor.