An improved synthesis of [15N] 16‐doxyl stearic acid

An improved method for the synthesis of [15N] 16‐Doxyl stearate, a fatty‐acid spin label, is reported. The method requires only one mole of [15N] 2‐amino‐2‐methyl propanol per mole of methyl keto stearate with an overall yield of about 50%. In contrast, the previous method produced only 1‐3% yield. The great improvement in yield was achieved mainly through the reduction of reaction volume which increases the reaction rate by the law of mass action.