abstract |
A method is disclosed for the preparation of optically pure isomes of formeterol, especially the (R,R)- and (S,S)-isomer, by the reaction of an optically pure 4-benzyloxy-3-formamidostyrene oxide with an optically pure 4-methoxy-α-methyl-N-(phenylmethyl)benzeneethanamine followed by debenzylation. Useful intermediates in the process are also disclosed, as is the novel L-tartrate salt of R,R-formoterol. |