Ethyl-l-phenylphospholanium Perchlorate

Treatment of the aqueous layer with 50 mL of a saturated sodium perchlorate solution affords a white precipitate that is collected and recrystallized from absolute ethanol-diethyl ether (1 3). The absolute ethanol should be added drop- 

Gillespie, F. Ramirez, 1. Ugi, and D. Margquarding./lngew. Chem. Int. Ed. Engl, 12, 91 (1973) and references cited therein. 

Quaternary Phosphonium Compounds, in Organic Phosphorus Compounds, G. M. Kosolapoff and L. Maier, (eds.), Vol. 2, John Wiley-Interscience, New York, 1972, Chap. 4. 

For a summary of the synthesis of phosphines see L. Maier, Primary, Secondary, and Tertiary Phosphines, in Organic Phosphorus Chemistry, Vol. 1, G. M. Kosolapoff and L. Maier (eds.), John Wiley-Interscience, New York, 1972, Chap. 1 D. M. Hellwege and K. D. Berlin, in Topics of Phosphorus Chemistry, Vol. 6, Interscience Publishers, New York, 1969, pp. 1-186 T. E. Snider, C. H. Chen, and K. D. Berlin,/%osp/ton/s, 1, 81 (1971). 

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The present procedure starts with ethyldiphenylphosphine, which is cleaved by lithium in tetrahydrofuran to lithium ethylphenylphosphide. This phosphide under vigorous reflux cleaves tetrahydrofuran to afford a necessary precursor, 4-(ethylphenylphosphino)-1 -b utanol (ethyl(4-hydroxybutyl)pheny Iphosphine). This(hydroxyalkyl)phosphine then is cyclized intramolecularly to give 1-ethyl-l-phenylphospholanium perchlorate. 

Caution. In view of the well-known shock sensitivity of organic perchlorates, 1-ethyl-l-phenylphospholanium perchlorate should be handled with care. Attempts to detonate 1-6 mg samples with a hammer on a concrete surface failed to produce an explosion. It is quite probable that salts with the PFi ion can be produced by using KPFf, in place of NaClO, but this is not done in the present example. 

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