Nitropyridyl isocyanates

✍ Scribed by Jarle Holt; Trygve Andreassen; Jan M. Bakke; Anne Fiksdahl

• Publisher: Journal of Heterocyclic Chemistry
• Year: 2005
• Tongue: English
• Weight: 99 KB
• Volume: 42
• Category: Article
• ISSN: 0022-152X
• DOI: 10.1002/jhet.5570420213

✦ Synopsis

We hereby report the first preparation of 3-nitro-4-pyridyl isocyanate 9 and 5-nitro-2-pyridyl isocyanate 18. They were formed by Curtius rearrangement of the corresponding acyl azides 8 and 17, prepared from methyl 3-nitro-4-pyridinecarboxylate 6 via the hydrazide 7 and 5-nitro-picolinic acid 16, respectively. The substrates 6 and 16 were generated by nitration of methyl 4-pyridinecarboxylate 5 and nitration and oxidation of 2-picoline 14. 3-Nitro-4-pyridyl isocyanate 9 can be stored in dry solution and is stable at room temperature for several weeks while 5-nitro-2-pyridyl isocyanate 18 was less stable and should be used for synthetic purposes immediately.