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Extra info for Advances in Heterocycling Chemistry. Vol. 44
A new catalytic procedure has made it possible to prepare alkyl sodium amides in good yields and in reasonable time. The ADVANCES I N T H E C H I C H I B A B I N R E A C T I O N Sec. B] n-BuNH, + Na catalyst PhCH, 33 d3uNHNa procedure involved refluxing sodium sand and the amine in toluene with a catalyst consisting of a 3- or 4-alkylpyridine, 3,3’-dialkyl-2,2’-bipyridine, or 3or 4-alkylquinoline. The preformed alkyl sodium amide underwent a normal Chichibabin reaction with evolution of hydrogen at lower temperatures than required for sodium amide (83USP4405790).
C] ADVANCES IN THE CHICHIBABIN REACTION 49 sium permanganate, afforded 4-amino-3,6-dimethoxypyridazine(164) and 4-amino-3-methoxypyridazine (165), respectively (86JHC621). The latter reaction gave 3,3'-dimethoxy-4,4'-bipyridazine(166) as a side product (Scheme 61). Substituted pyrimidines undergo amination when treated with potassium amide in liquid ammonia and oxidized with potassium permanganate. For example, Sphenylpyrimidine (167) afforded 4-amino-5-phenylpyrimidine (168) in 70':/, yield (Scheme 62) (86MI2).
The results are given in Table 11. 1:1 (Scheme 22). 5: 1 of 62:61 reported by Siegl for the amination of 60 in DMA at atmospheric pressure (81JHC1613). The total yield of both isomers in the pressure reaction was 81% (84EUP0098684A2). Only one isomer was observed from the pressure amination of niacin and nicotinamide. The acid (63), treated with sodium amide in xylene under the same pressure conditions as for 3-picoline, gave 6-aminonicotinic acid (64) in 26 CHARLES K. McGILL A N D ANGELA RAPPA QcoNHz 350 si /&* HzN (67) \ ~~~~z (68 SCHEME 23 1 [Sec.