Preparation of secondary alkoxyalkanoic acids

Claim 1

A process for the preparation of a secondary alkoxyalkanoic acid of the formula RO(CH.sub.2 CHR'O).sub.n CH.sub.2 CO.sub.2 H wherein R is a secondary alkyl group having from 3 to about 1000 carbon atoms, R' is hydrogen or alkyl or mixtures thereof (on the individual molecule) and n is an integer of from 1 to about 200, which comprises reacting the corresponding secondary alkoxyalkanol with a stable free radical nitroxide having the formula: ##STR9## wherein (1) (a) each of R 1 , R 2 , R 3 and R 4 is an alkyl, aryl or heteroatom substituted alkyl group having 1 to about 15 carbon atoms, and (b) R 5 and R 6 (i) each is an alkyl group having 1 to about 15 carbon atoms provided that R 1 -R 6 are not all alkyl groups, or a substituted alkyl group having 1 to about 15 carbon atoms wherein the substituent is hydrogen, cyano, --CONH 2 , --OCOCH, OCOC 2 H 5 , carbonyl, alkenyl wherein the double bond is not conjugated with the nitroxide moiety, or --COOR wherein R of the --COOR group is alkyl or aryl, or (ii) together form part of a ring that contains 5 carbon atoms and up to two heteroatoms of O or N, or (2) the ##STR10## moiety individually are aryl, in the presence of a NO x -generating compound and an oxidant at a temperature in the range of from about 0° C. to about 100° C. and thereafter separating out the secondary alkoxyalkanoic acid.