Effective Synthesis of α,ω-Diaminoalkanes by the Optimized Gabriel Method

Key Points

• The aim is to optimize the Gabriel method for synthesizing α,ω-diaminoalkanes.
• Alkylation of phthalimide with α,ω-dibromoalkanes in dimethylformamide.
• Use of anhydrous potassium carbonate as a base.
• Hydrolysis of the resulting dibromoalkanes in potassium hydroxide.
• Steam distillation to isolate diamine bases.
• Neutralization of distillate with hydrochloric acid.
• Successful conversion of phthalimide to α,ω-diaminoalkanes.
• Overall yields of 90–96% for the target dihydrochlorides.