| 摘要 |
<p>A novel two-step reaction process for preparing 5-substituted-2-methoxybenzaldehyde compounds is disclosed wherein the substituent group is either isopropyl or trifluoromethoxy. The process involves (1) reacting a corresponding 4-substituted phenol compound with dimethyl carbonate in the presence of a tertiary-amine base to form the corresponding 4-substituted anisole compound, and (2) thereafter subjecting the latter intermediate product obtained in the first step to aromatic C-formylation on the ring with hexamethylenetetramine in the presence of trifluoroacetic acid, followed by hydrolysis, to ultimately yield the desired aldehyde compound. The two aromatic aldehyde compounds so obtained, viz., 2-methoxy-5-trifluoromethoxybenzaldehyde and 2-methoxy-5-isopropylbenzaldehyde, are known to be useful as intermediates that specifically lead to (2S^_,3S^_)-c^_i^_s^_-3-(2-methoxy-5-trifluoromethoxybenzyl)amino-2-phenylpiperidine and (2S^_,3S^_)-c^_i^_s^_-2-(diphenylmethyl)-N-[(2-methoxy-5-isopropylphenyl)methyl]-1-azabicyclo[2.2.2.]octane-3-amine, respectively. The latter final products, in turn, are both known to be useful in the field of medicinal chemistry as substance P receptor antagonists.</p> |
