Hydroxypyridines N-oxidation

Nitration of 2-substituted-3-hydroxypyridine N-oxides (9.94) gave —50% yield of 4-nitro derivatives, as also did 2,6-dimethyl-3-hydroxypyr-idine N-oxide (70BAU2440). 

Benzyl-3-hydroxypyridine W-oxide (9.105) is iodinated in the 4- and 6-positions (cf. other reactions described in, Section 6) (74BAU2023), as is 3-hydroxypyridine N-oxide (66RC1875). 

Azo-coupling of 5-benzyl-3-hydroxypyridine N-oxide (9.105) goes only into the 2-position, probably because of steric hindrance to 6-substitution (74BAU2023). 

Cationic complexes are formed with 1,3-diketones, 2-hydroxypyridine N-oxide and tropolones (325). For example, tris(acetylacetonato)silicon (IV) chlo-... 

Methyl fluorosulfonate 2,6-Dicyanopyridines from 3-a-hydroxypyridine N-oxides... 

Ri = OH 2-Hydroxypyridine-N-oxide Ri = SH 2-Mercaptopyridine-N-oxide R2 = O I-Hydroxy-(IH) pyridine-2-one R2 = S I-Hydroxy-(IH) pyridine-2-thione... 

Table 100 Minimum inhibition concentrations (MIC) of 2-hydroxypyridine-N-oxide (Source PYRION-CHEMIE)...

Example 1 SMD Structure of 2-Hydroxypyridine-N-oxide. Our first example deals with a single molecule. The molecular diagram and the corresponding SMD file are given in Figure 2 with detailed information on the meaning of the different entries described in italic letters. The SMD file starts with a special start record for an SMD structure ... 

Figure 3. Information hierarchy in the SMD structure of 2-Hydroxypyridine-N-oxide given by Figure 2.

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