| abstract |
The invention concerns a method of preparing oxazines or oxazolines in which 3-propanolamides or ethanolamides of carboxylic acids are condensed, optionally in the presence of a catalyst, at elevated temperatures and reduced pressure. The method is characterized in that, during the reaction, a slow stream of nitrogen is passed through the reaction vessel to drive out the water of reaction formed, and the oxazolines or oxazines formed are distilled off directly by a thin-film evaporator. |