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|Section2= |Section7= }} The Cornforth reagent or pyridinium dichromate (PDC) is a pyridinium salt of dichromate with the chemical formula ()2(). This compound is named after the Australian-British chemist Sir John Warcup Cornforth (b. 1917) who introduced it in 1962.〔Alexander Senning (Elsevier's dictionary of chemoetymology: the whies and whences of chemical nomenclature and terminology ), Elsevier, 2007, ISBN 0-444-52239-5 p. 94〕 The Cornforth reagent is a strong oxidizing agent which can convert primary and secondary alcohols to aldehydes and ketones respectively. In its chemical structure and functions it is closely related to other compounds made from hexavalent chromium oxide, such as pyridinium chlorochromate and Collins reagent. Because of their toxicity, these reagents are rarely used nowadays. ==Synthesis and properties== The Cornforth reagent is prepared by slow addition of a concentrated aqueous solution of chromium trioxide to pyridine. The reaction may cause explosion, which is avoided by thoroughly dissolving the trioxide in water and cooling the solution by ice. The product is filtered, washed with acetone and dried, yielding an orange powder. The powder is stable in air, not particularly hygroscopic and has an almost neutral pH that facilitates its handling; it is only slightly acidic owing to the presence of pyridinium cations. The Cornforth reagent is readily soluble in water, dimethylformamide and dimethyl sulfoxide (DMSO). It is poorly soluble in acetone and chlorinated organic solvents, such as dichloromethane, and forms suspensions.〔Steven V. Ley (Oxidation ), Elsevier, 1992, ISBN 0-08-040598-3 p. 272〕〔 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Cornforth reagent」の詳細全文を読む スポンサード リンク
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