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An efficient and general strategy for the synthesis of 4-phosphorylated pyrazoles from β-hydrazono phosphine oxides

✍ Scribed by Francisco Palacios; Domitila Aparicio; Jesús M. de los Santos

Publisher
Elsevier Science
Year
1996
Tongue
French
Weight
630 KB
Volume
52
Category
Article
ISSN
0040-4020

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✦ Synopsis

A simple and efficient synthesis of aminopyrazoles substituted with a phospkino oxide and sulphide groups in the 4-position 1 is described. The key step is a regioselective addition of fithiated [~hydrazonophosphine oxides 2 to isocyanates and isothiocyanates to give functionalized amides 3 and 7. Subsequent cyclization of 3 with phosphorus oxychloride in the presence of triethylamine afforded pyrazoles derived from phosphine oxides 1 and phosphine sulphides g. Substituted heterocycles 1 can also be obtained in "one pot" reaction from phosphine oxides 2 when these compounds are metaUated followed by addition of isocyanates and phosphonas oxychloride.

📜 SIMILAR VOLUMES

An efficient strategy for the regioselec
An efficient strategy for the regioselective synthesis of 3-phosphorylated-1-aminopyrroles from β-hydrazono phosphine oxides and phosphonates
✍ Francisco Palacios; Domitila Aparicio; Jesús M. de los Santos 📂 Article 📅 1999 🏛 Elsevier Science 🌐 French ⚖ 837 KB

Abstmt: An easy strategy for the synthesis of 1-aminopyrroles substituted with a phosphine oxide or phosphonate group in the 3-position is described. The key step is the 1,4-conjugate addition of the enamine to the 4-phosphorylated 1,2-diazabuta-1,3-diene 3 and heterocyclisation to give substituted

ChemInform Abstract: An Easy Strategy fo
ChemInform Abstract: An Easy Strategy for the Synthesis of 5-Phosphorylated Pyrimidin-2,4-diones from β-Phosphine Oxide and Phosphonate Enamines.
✍ Francisco Palacios; Domitila Aparicio; Ana M. Ochoa de Retana; Jesus M. de los S 📂 Article 📅 2010 🏛 John Wiley and Sons ⚖ 35 KB 👁 2 views

An Easy Strategy for the Synthesis of 5-Phosphorylated Pyrimidin-2,4-diones from β-Phosphine Oxide and Phosphonate Enamines. -An efficient synthesis of the title 5-phosphorylated pyrimidinediones (III), (V) and (VII) is presented involving the base-catalyzed cyclization of functionalized enamides/im