What is "diazald"

N-Methyl-N-nitroso-p-toluenesulfonamide, known commercially as Diazald, is used as a relatively safe and easily handled precursor to diazomethane, which is toxic and unstable.

Upon the addition of a base such as sodium hydroxide or potassium hydroxide, an elimination reaction occurs to produce diazomethane as well as p-toluenesulfonic acid as a side product, according to the following mechanism: