Patent ID: 8754074

Claim:
A method of synthesising the (R) enantiomer of mequitazine from the (R) enantiomer of vinyl quinuclidine of the following formula 2: comprising the following successive steps: (a) oxidative cleavage of the double bond of the (R) enantiomer of the vinyl quinuclidine of formula 2 to give the aldehyde of the following formula 8: for which the carbon atom marked with a star is of (R) configuration, (b) reduction of the aldehyde of formula 8 obtained at the preceding step (a) to give the alcohol of the following formula 9: for which the carbon atom marked with a star is of (R) configuration, (c) activation of the OH function of the alcohol of formula 9 obtained at the preceding step (b) to give a compound of the following formula 10: for which the carbon atom marked with a star is of (R) configuration and R3 represents a leaving group, selected from a halogen atom, a mesylate (CH 3 —S(O 2 )O—), a triflate (CF 3 —S(O) 7 O—) and a tosylate (p-Me—C 6 H 4 —S(O) 2 O—), and (d) coupling of the compound of formula 10 obtained at the preceding step (c) with phenothiazine to give the (R) enantiomer of mequitazine.