Process for preparing a haze-free detergent and corrosion inhibiting additive for motor fuels

In a method for preparing a primary aliphatic hydrocarbon alkylene substituted asparagine in which one mole of maleic anhydride is reacted with approximately two moles of a N-alkyl-propane diamine composition represented by the formula:

• R--NH--(CH.sub.2).sub.3 --NH.sub.2
• in which the typical chain distribution of R is 0.5% dodecyl (C-12);
• 3.5% tetradecyl (C-14);
• 0.5% pentadecyl (C-15);
• 4.0% hexadecyl (C-16);
• 1.0% heptadecyl (C-17);
• 14.0% octadecyl (C-18);
• 1.5% tetradecenyl (C-14);
• 5.0% hexadecenyl (C-16);
• 67.0% (C-18):
• 3.0% octadecadienyl (C-18);
• and wherein said primary aliphatic hydrocarbon alkylene substituted asparagine product is characterized by being hazy or becoming hazy on standing, the improvement which comprises conducting said reaction between said maleic anhydride and said N-alkylpropane diamine composition in the presence of from about 0.5 to 5 weight percent based on the weight of N-alkyl propane diamine mixture of a phenolic compound represented by the formula:
• ##STR3## in which R.sub.1 and R.sub.2 each represent hydrogen or an alkyl radical having from 1 to 9 carbon atoms and the total number of carbon atoms in R.sub.1 and R.sub.2 does not exceed 9.