HYDROLYSIS OF ISOMERIC IMIDATE ESTERS.

Article abstract of DOI:10.1021/ja00518a031

A study has been made of the hydrolysis of the geometrical isomers of ethyl N-methyl-N-isopropylacetimidate in aqueous solution of 30 degree C ( mu equals 0. 5). The E isomer is quantitatively converted to amine and ester in dilute HCl, and to 65% amine at pH greater than 12, with the midpoint of the transition in products at pH 10. 2. Hydrolysis of an equimolar mixture of the E and Z isomers gives the same yield of amine as was obtained from the E isomer over the entire pH range. The partial interconversion of the imidate isomers that occurs during hydrolysis at alkaline pH probably proceeds via an enamine intermediate, as shown by the exchange of 33% of the hydrogen of the alpha -methyl group of the imidate when hydrolysis is carried out in D//2O. Calculations based on the extent of hydrogen-deuterium exchange which accompanies hydrolysis indicate that at least 40% of the imidate undergoes hydrolysis without prior isomerization.