Synthetic process for aminocyclohexyl ether compounds
Methods for the preparation of stereoisomerically substantially aminocyclohexyl ether compounds such as trans-(1R,2R)-aminocyclohexyl ether compounds and/or trans-(1S,2S)-aminocyclohexyl ether compounds as well as various intermediates and substrates are disclosed.
1. A method of stereoselectively making a compound of formula (18):
or a pharmaceutically acceptable salt thereof, which method comprises:
(a) treating a compound of formula (12):
to resolution conditions to yield a compound of formula (14):
where Bn is benzyl;
(b) reacting the compound of formula (14) with a compound of formula (16):
where Me is methyl, under suitable conditions comprising the presence of a Lewis acid or a Bronsted acid such that upon reaction of the compound of formula (14) with the compound of formula (16), the stereochemical configuration of the carbon to which the hydroxyl group is attached in the compound of formula (14) is retained in the resulting compound of formula (17):
where Bn is benzyl and Me is methyl;
(c) removing the benzyl from the compound of formula (17) under suitable conditions to form a compound of formula (18), as described above; and
(d) optionally converting the compound of formula (18) under suitable conditions to a pharmaceutically acceptable salt.
2. The method of claim 1 further comprising a method of making the compound of formula (12) wherein the method comprises reacting a compound of formula (11):
where Bn is benzyl, or a pharmaceutically acceptable salt thereof; with a compound of formula (1):
under suitable conditions to form a compound of formula (12).
3. The method of claim 1 further comprising a method of making the compound of formula (16) wherein the method comprises treating a compound of formula (15):
where Me is methyl, with trichloroacetonitrile under suitable conditions to form the compound of formula (16).
4. The method of claim 1 wherein the resolution conditions are chiral resolution conditions.
5. The method of claim 4 wherein the chiral resolution conditions comprise first treating the compound of formula (12) with di-O,O-p-toluoyl-L-tartaric acid under suitable conditions to form a mixture of diastereomeric salts and then isolating the compound of formula (14) from the mixture.
6. The method of claim 1 wherein the resolution conditions are kinetic resolution conditions.