[Structure: see text] Lithiation of 5-bromonicotinic acid protected as secondary or tertiary amide as well as (4,4'-dimethyl)oxazoline with lithium amides is reported. The unusual C-2 and C-4 regioselective lithiation of 3-bromo-5-(4,4'-dimethyl)oxazolinylpyridine using LTMP versus LDA was observed, providing a new route to substituted nicotinic acid scaffolds. The methodology was applied to the synthesis of novel C-4 and C-6 arylated 5-bromonicotinic acids.
The hydrogenation of N‐unsubstituted cyclic imides to the corresponding cyclic amines has been performed selectively with heterogeneous catalysts obtained from rhodium and molybdenum carbonyl precursors. Various substrates were reduced in good to high yields and selectivities. Platinum‐based catalysts also proved to be efficient. Furthermore, gram‐scale experiments were performed and the catalysts could be recycled.
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