2-Methyl-2-nitrosopropane

2-Methyl-2-nitrosopropane (MNP or t-nitrosobutane, chemical formula (CH3)3CNO) is a spintrap. This molecule forms adducts with unstable free radicals to form a more stable paramagnetic nitroxide radical that can be detected by electron spin resonance spectroscopy. It is particularly useful for trapping carbon-centered tyrosyl radicals.

MNP is also the aerial oxidation product of t-butylhydroxylamine (NtBHA), which in turn is a hydrolysis product of phenylbutylnitrone and similar spintraps. MNP has pharmacological action, both by scavenging free radicals and possibly by releasing the messenger substance nitric oxide in the presence of light and under oxidizing conditions. Production of NtHBA and its parent spintrap MNP may account for the sometime antistroke action of the drug NXY-059.

MNP is also an efficient regulator of the radical polymerization of methyl methacrylate through the 'pseudoliving' chain mechanism.