Nitronium tetrafluoroborate hydrazines

The results of nitration reactions depend on reagents and the acidity of the medium. Thus fuming nitric acid in concentrated sulfuric acid converts (410a) to the 3-nitro derivative while with acetyl nitrate reaction occurs exclusively at C-4 (equation 50). The nitration in the 4-position can also conveniently be done with nitronium tetrafluoroborate. The reduction of these nitro compounds by hydrazine in the presence of palladium on charcoal provides a versatile route to 4-amino-7,6-borazarothieno[3,2-c]pyridines (75ACS(B)46l>. In the nitration of 4,5-borazarothieno[2,3-c]pyridines (e.g. 409a), peri effects from the substituents on the boron atom lead to formation of a considerable amount of the 2-nitro derivatives. 

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See also in sourсe #XX -- [ ]

See also in sourсe #XX -- [ ]

See also in sourсe #XX -- [ , ]

See also in sourсe #XX -- [ , ]

See also in sourсe #XX -- [ ]

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