| abstract |
A process for producing a compound of the formulan(II):n nwherein R 1 , R 2 , R 3 and R 4 are each independently e.g.nhydrogen, alkyl or alkoxy, R 5 is alkyl or alkoxyalkyl,nA is 0 or S, Ar is aryl, * represents the position ofnan asymmetric carbon atom and the compound is the (R)nor (S) isomer and Q is an optical resolution reagent,ncomprising isolating the compound as crystals from ansolution or suspension containing the compound of thenformula (II) wherein * represents that the compound isnthe (R) or (S) isomer or a mixture thereof and thenother symbols are the same as above. |