Tris(pyrrolyl)phosphine

Abstract

[60259-30-5] C12H12N3P (MW 229.22) InChI = 1S/C12H12N3P/c1-2-8-13(7-1)16(14-9-3-4-10-14)15-11-5-6-12-15/h1-12H InChIKey = QEILNSNBJVMEKR-UHFFFAOYSA-N (used as ligand on several metals) Physical Data: mp 43–44 °C. Solubility: acetone, CH2Cl2, chloroform, THF, not soluble in methanol or hexane. Form Supplied in: white solid. Preparative Methods: the first synthesis was carried out by adding an ethereal solution of PCl3 to an ethereal solution suspension of 20% excess potassium pyrrolide. After 24 h, the precipitate of KCl and excess potassium pyrrolide was filtered off and the solvent removed under vacuum yielding crude tris(pyrrolyl)phosphine with yields ranging from 70% to 95%.1 Many years later, an alternative synthesis was described.2 In a flame-dried Schlenk reactor under inert atmosphere, pyrrole and triethylamine in THF are cooled to −78 °C, then PCl3 added, and the reaction mixture allowed to warm to room temperature. After heating for 24 h at 65 °C, a colorless solid appeared and was filtered and washed with THF. Filtrates were combined and taken to dryness under vacuum yielding a crystalline off-white mass. The product was dissolved in hexane and impurities removed by filtration. Concentration of the solution and cooling to −78 °C gave the product as colorless crystals (74%). Purification: crystallization from methanol solution,1 or crystallization from cold hexane.2 Spectroscopic Data: 1H (toluene d8) δ6.55 (m, 6H), 6.21 (m, 6H); 31P (toluene d8) δ79.6. Handling, Storage, and Precautions: described as air and moisture stable.