N-Nitration of Secondary Amines with 4-Chloro-5-methoxy-2-nitropyridazin-3-one
摘要:
N-Nitration of 4-chloro-5-substituted-pyridazin-3-one with copper nitrate trihydrate in acetic anhydride gave the corresponding 4-chloro-2-nitro-5-substituted-pyridazin-3-one. 4-Chloro-5-alkoxy-2-nitropyridazin-3-ones such as 5-methoxy (2b) and 5-ethoxy (2d) derivatives showed excellent nitro group transfer potentiality. N-Nitration of some secondary amines with 2b gave the corresponding N-nitramines under mild neutral condition in good yields.
(6-Oxo-6H-pyridazin-1-yl)phosphoric acid diethyl esters (3) are efficient and selective coupling agents for equimolar esterification of carboxylicacids and alcohols. Esterification of aliphatic and aromatic carboxylicacids with aliphatic and aromatic alcohols using 3 afforded the corresponding esters chemoselectively in good to excellent yield.
In order to confirm the regiochemistry for the functionalization of 1-(1,1-dibromo-2-oxopropyl)-4,5-dihalopyridazin-6-ones, the dehalogenation of 1-methyl-5-halo-4-substituted-pyridazin-6-ones using Pd/C and hydrogen was carried out. The results of the title reaction are reported.
Retro-Ene reaction.<b>VI.</b>Functionalization of 4,5-dihalopyridazin-6-ones using 1-acetyloxymethyl-4,5-dihalopyridazin-6-ones as the 1-O, 3-N, 5-O ene-adduct
Functionalization of 1-acetyloxymethyl-4,5-dihalopyridazin-6-ones via retro-ene reaction with some nucleophiles gave regioselectively only 5-halo-4-substitutedpyridazin-6-ones.
Functionalization of 4,5-dihalopyridazin-6-onesusing1-(1,1-dibromo-2-oxopropyl)-4,5-dihalopyridazin-6-ones with some nucleophiles gave regioselectively only 5-halo-4-substituted-pyridazin-6-ones.
Functionalization of 1-hydroxymethyl-4,5-dihalopyridazin-6-ones via a retro-ene reaction with some nucleophiles gave regioselectively only 5-halo-4-substitutedpyridazin-6-ones.