Nitriles, pyrrolidones from

A more highly substituted pyrrolidone, doxapram, shows activity as a respiratory stimulant. Preparation of this agent involves an interesting rearrangement, which in effect results in a ring exchange reaction. Alkylation of the anion from diphenylacetonitrile with the chloropyrrolidine 14 affords 15. Hydrolysis of the nitrile function leads to the... 

Because of the repulsion of the cyanide groups the polymer backbone assumes a rod-like conformation. The fibers derive their basic properties from this stiff structure of PAN where the nitrile groups are randomly distributed about the backbone rod. Because of strong bonding between the chains, they tend to form bundles. Most acrylic fibers actually contain small amounts of other monomers, such as methyl acrylate and methyl methacrylate. As they are difficult to dye, small amounts of ionic monomers, such as sodium styrene sulfonate, are often added to improve their dyeability. Other monomers are also employed to improve dyeability. These include small amounts (about 4%) of more hydrophilic monomers, such as -vinyl-2-pyrrolidone (Equation 6.69), methacrylic add, or 2-vinylpyridine (Equation 6.70). 

There remains a collection of syntheses from relatively uncommon precursors. One that has seen a modest amount of exploration involves the use of pyrrolidones as precursors. Thus the iV-tosyl-2-pyrrolidone 172 reacts with nitriles to give partially reduced pyrrolo[2,3-r/ pyrimidines 173 (Equation 64) <1996T7973>. 

An unusual rearrangement provides the key to the preparation of a highly substituted pyrrolidone, doxapram (26-7), that is used as a respiratory stimulant. The synthesis starts with the displacement of chlorine on pyrrolidine (26-1) by the carbanion from diphenylacetonitrile (26-2) to give (26-3) as the product. The quite hindered nitrile is then hydrolyzed to the corresponding carboxylic acid (26-4) by basic hydrolysis. The reaction of acid with thionyl chloride presumably proceeds initially to form the corresponding acid chloride. The close proximity of that group to basic... 

By this method, 1-bromonaphthalene affords 1-naphthonitrile in 94% yield after refluxing for 4 hrs. with pyridine as solvent the reaction mixture is heated in an oil bath at 215-225° for 15 hrs., and the yield is 82-90%. Efficient procedures for liberating the nitrile from the cuprous halide complex involve pouring the brown reaction mixture into an aqueous solution of ferric chloride (oxidizes Cu+ to Cu ", which forms no complex), ethylenediamine (forms complexes with Cu+ and Cu " ), or sodium cyanide (forms soluble sodium cuprocyanide). The higher-boiling N-methyl-2-pyrrolidone (b.p, 202°) is also satisfactory, but is more expensive. 

Presumably the mesomeric 3a,5a-cyclo-cation (442) suffers nucleophilic attack by the nitrile hydrolysis of the resulting cation (443) gives the amide (444). The reaction provides a convenient route from cholesterol to 3)5-acetamido-cholest-5-ene. Use of 4-chlorobutyronitrile gives the corresponding chloro-amide, which is readily hydrolysed to the amine hydrochloride or cyclized by base to give the pyrrolidone (445). 

N-Condensed benzothiazoles. A soln. of N-(o-bromophenyl)-5-/ r/-butylthio-2-pyrrolidone and Bu3SnD in deaerated benzene containing a little azodiisobutyro-nitrile refluxed under N2 until reaction complete (4-18 h) 2,3-benzo-8-oxo-4-thia-l-azabicyclo[3.3.0]octane. Y 89%. F.e. incl. N-condensed 2//-l,3-benzothiazines from N-(o-bromobenzyl)-analogs s. A.L.J. Beckwith, D.R. Boate, J. Org. Chem. 53, 4339-48 (1988). 

Table 17.3 compares the solvency of a 60 vol% nitroethane and 40 vol% toluene blend for a nitrile-butyl rubber as compared to the solvents cyclohexanone and N-methyl 2-pyrrolidone. A Lotus 123 spreadsheet, DECITREE.WKl, was used to generate Table 17.3. This spreadsheet is included on the computer disk accompanying this book. The spreadsheet allows one to compare the solubility parameters of solvents with a selected resin. The values for the selected resin are supplied by the user while the solvent data is available from the lookup tables. The typical R values are calculated and the location of...

Figure 17.2 Hansen solvency on a polarity versus hydrogen bonding plot of a 60 vol% nitroethane and 40 vol% toluene blend for a nitrile-butyl rubber as compared to the solvents cyclohexanone and N-methyl 2-pyrrolidone. This plot comes from the solvency comparisons shown in Table 17.3.

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