Patent ID: 7351865

Claim:
A method for the synthesis of severely sterically hindered secondary aminoether alcohols of the formula wherein R 1 and R 2 are each selected from the group consisting of alkyl, hydroxylalkyl radicals having 1 to 4 carbon atoms or in combination with the carbon atom to which they are attached they form a cycloalkyl group having 3 to 8 carbon atoms, and R 3 is selected from the group consisting of hydrogen, alkyl or hydroxyalkyl radicals having 1 to 4 carbon atoms, and R 4 , R 5 , R 6 , R 7 , R 8 , R 9 , R 10 and R 11 are the same or different and are selected from the group consisting of hydrogen, alkyl and hydroxyalkyl radicals having 1 to 4 carbons provided that at least one of R 4 or R 5 bonded to the carbon atom directly bonded to the nitrogen atom is an alkyl or hydroxyalkyl radical when R 3 is hydrogen, the process involving reacting an organic carboxylic acid anhydride, an organic carboxylic acid halide, or mixture thereof, of the general formula wherein R 12 and R 13 are the same or different and each is selected from the group consisting of alkyl radicals having 1 to 4 carbon atoms, aryl radicals having hydrogen or C 1 -C 10 alkyl radicals substituted therein, and mixtures thereof, and X is a halogen selected from the group consisting of F, Cl, Br, I, and mixtures thereof, with sulfur trioxide, SO 3 , to yield a mixed sulfonic-carboxylic anhydride or (mixed anhydride) sulfonyl halide anhydride of formula (2) which is reacted with a dioxane of formula (3) wherein R 4 , R 5 , R 6 , R 7 , R 8 , R 9 , R 10 and R 11 are the same or different and are selected from hydrogen, alkyl and hydroxyalkyl radicals having 1 to 4 carbons, to yield which is then aminated with an alkylamine of the formula wherein R 1 , R 2 and R 3 are as previously defined, to yield (6) which is subsequently hydrolyzed with base to yield product (1).