2,2-Dimethylcysteamine hydrochloride (1-amino-2-methylpropane-2-thiol hydrochloride) is a sterically hindered aminothiol that melts at 170–172 °C and is freely soluble in water, methanol and DMF.
The compound is a key building block for the veterinary antibiotic tiamulin and its analogue valnemulin: the masked thiol side-chain is first acylated with the appropriate diterpenic acid and then deprotected to give the final pleuromutilin derivative . In materials chemistry the tertiary thiol is used as a redox-cleavable cross-linker for hydrogels and microgels; disulfide bridges formed on oxidation allow reversible protein capture and release in microfluidic chips . Additionally, the hindered thiol serves as an odour-free chain-transfer agent in the emulsion polymerisation of acrylic monomers, enabling low-Mw, narrow-PDI dispersions for pressure-sensitive adhesives.
Store under nitrogen at 2–8 °C to prevent slow oxidation to the disulfide. The powder is harmful if swallowed (rat oral LD₅₀ 560 mg kg⁻¹) and is irritating to the respiratory tract; handle with gloves and local exhaust ventilation.
