DUPONT DMF REACTION SOLVENT NEWS When you think of the Wittig reaction, think of DMF Discover the opportunities for improving products and processes with Du Pont DMF
DMF gives excellent results in high yields when used as a solvent with Wittig reagents DMF offers advantages as a medium for carrying out Wittig reactions because several phases can be carried out in the same solvent. High yields often accompany the preparation of triphenylphosphonium salts when prepared in DMF. Stereospecific Wittig reaction in DMF When the stereospecific synthesis of cis-olefins from alkylidene triphenylphosphoranes and aliphatic aldehydes was carried out in DMF, optimum yields of the cis-olefins were achieved [Tetrahedron, 23, pp. 2709-2720 (1967)].
/C
=0
+
c|),P = C R'
DMF 20°, Ibr.
Economy in production-scale use DMF is the least expensive of the "super" (highly dipolar aprotic) solvents-25^ per lb. for bulk quantities. In addition, easy recovery, high conversions and faster reaction rates result in low use-costs. Versatility in chemical processes DMF is used in the manufacture of a wide range of products, involving many classes of organic reactions, often wrth existing equipment. Efficiency through high yields and pure products Higher conversions and faster reaction rates are often possible with DMF, resulting in higher product yields. Product purity results from reduced by-product contamination.
V
High yields from DMF An 89.4% yield of a phosphonium salt was achieved by refluxing triphenylphosphine with o-xylylene dibromide three hours in DMF [J. Org. Chem., 27, p. 1627, (1962)].
CH8Br CH2Br
*P
DMF
CH t P,Br
rfx.3hr.
CHt*P4>,Br"
Easy recovery DMF can easily be recovered by simple distillation at atmospheric or reduced pressure. High recoveries (up to 99%) not only reduce production costs, but also improve pollution control. Du Pont's new DMF Recovery and Purification Bulletin provides basic data on methods and equipment for recovery of DMF in production operations. Mail the coupon for more information on Du Pont DMF.
Isoprenoids synthesized in one flask
In the total synthesis of /3-carotene and Vitamin A, DMF proved an excellent solvent for the conversion of the alcohol to the phosphonium compound followed by the appropriate aldehyde to produce the olefin. All synthesis steps were carried out in one flask (Pommer Sarnecki, German Patent 1,068,710).
>™ + *> p + HBr iSsr
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