The gold–acid‐co‐catalyzed synthesis of nine series of fused azaheterocycles with structural diversity starting from the same synthons as readily available propargylic hydroperoxides and aromatic amines has been achieved. The overall tandem process consists in a gold‐catalyzed hydroperoxide rearrangement/Michaelreaction followed by a final acid‐catalyzed cyclization.
Lithiation of 3-(4, 4-dimethyl-2-oxazolin-2-yl)pyrazolo[1, 5-a]pyridine (1a) with 2 molar equivalents of n-BuLi followed by reaction with benzaldehyde yielded α-(4, 4-dimethyl-2-oxazolidinylidene)-6-(α-hydroxybenzyl)-2-pyridineacetonitrile (2a). Upon similar treatment of other electrophiles, the corresponding 2, 6-disubstituted pyridines 2 were produced. The formation of the pyridines proceeded through lithiation, reaction with an electrophile, and ring-cleavage of the pyrazole ring.
Quinuclidine derivatives processes for preparing them and their uses as m2 and/or m3 muscarinic receptor inhibitors
申请人:Guyaux Michel
公开号:US20050020660A1
公开(公告)日:2005-01-27
The invention concerns quinuclidine derivatives of formula I or II wherein the substituents are as defined in the specification, as well as their use as pharmaceuticals. The compounds of the invention_show high affinities for m3 and/or m2 muscarinic receptors and are particularly suited for treating urinary incontinence.
In the treatment of pyrazolo[1,5-a]pyridines with dimethylformamide and,phosphorus oxychloride, Vilsmeier-Haack formylation proceeded at the 3-position, giving 3-pyrazolo[1,5-a]pyridinecarboxaldehydes. Reaction of the pyrazolo[1,5-a]pyridine with acyl halide gave 3-acylpyrazolo[1,5-a]pyridines. Conversion of the formyl group into the alkenyl group was achieved easily by Wittig reaction.