This is the abstract of a presentation made by Phil Sass in the Sunday evening Division of Inorganic Chemistry poster session at the August 2001 National Meeting of the American Chemical Society in Chicago.

Preparation of Primary Alkylphosphines by a Phospha-Gabriel Route

Philip A. Sass, Jeffrey B. Johnson, Ryan C. Nelson, and Brian A. O'Brien, Department of Chemistry, Gustavus Adolphus College, 800 West College Avenue, Saint Peter, MN 56082, Fax: 507-933-7041,,

The classic Gabriel synthesis of primary amines through alkylation of potassium phthalimide, followed by cleavage with hydrazine, has long been known as the preferred method for preparation of primary amines from alkyl halides. Here we describe a phosphorus analog of the Gabriel synthesis. Alkylphthaloylphosphines [1,2-C6H4(CO)2P-R] or bisphthaloylphosphinoalkanes [C6H4(CO)2P-(CH2)n-P(CO)2C6H4] are readily prepared by reaction of cesium phthaloylphosphide [Cs+1,2-C6H4(CO)2P-] with alkyl halides. Cleavage of the phthaloylphosphines by phenylhydrazine (or hydrazine) produces N-phenylphthalhydrazide (or phthalhydrazide) and the corresponding primary alkylphosphine. The reactions proceed rapidly and in good yield, and isolation of the products is straightforward. Spectroscopic and chemical characterization of the phthaloylphosphines and primary alkylphosphines, as well as details of the synthetic procedures, will be presented.

left to right:
Phil Sass,
Ryan Nelson,
& Jeff Johnson
(click on photo to enlarge)