A pyrrolidone

Supplement 1953 3103-3241 Carbonyl compounds a-Pyrrolidone, 236. Tropinone, 259. Succinimide, 369. Isatin, 432. Phthalimide, 458. 

Anionic copolymerization of lactams presents an interesting example of copolymerization. Studies of the copolymerization of a-pyrrolidone and e-caprolactam showed that a-pyrrolidone was several times more reactive than e-caprolactam at 70 °C, but became less reactive at higher temperatures due to depropagation210 2U. By analyzing the elementary reactions Vofsi et al.I27 concluded that transacylation at the chain end occurred faster than propagation and that the copolymer composition was essentially determined by the transacylation equilibrium and the acid-base equilibrium of the monomer anion together with the usual four elementary reactions of the copolymerization. 

From the kinetic viewpoint the polymerizability of 61 is considered to be higher than that of e-caprolactam, which is polymerized usually at temperatures above 135 °C63,64 Thermodynamically, the polymerization of 61 appears to be more favored than that of a-pyrrolidone, for which no polymerization is observed in THF63-65 The higher polymerizability of 61 may be attributed not only to its highly strained bicyclic structure but also to the activation of the anion 66 by the... 

Although there is no evidence that the neuronal degeneration of AzD results, as in cardiovascular ischaemia, from the excitotoxicity of increased intracellular Ca +, some calcium channel blockers have been tried in AzD. They have had little effect but surprisingly a pyrrolidone derivative nefiracetam, which opens L-type voltage-sensitive calcium channels (VSCCs) reduces both scopolamine- and )S-amyloid-induced impairments of learning and memory in rats (Yamada et al. 1999). This effect can be overcome by VSCC antagonists, but nefiracetam has not been tried in humans. 

A trifluoromethyl anion is also difficult to generate because it easily lose a fluoride ion to form difluoro carbene. Shono and Kashimura et al have similarly achieved the generation of such a species from trifiuoromethane using the electrogenerated a-pyrrolidone anion. The efficient trifluoromethylation of aldehydes and ketones in the presence of hexamethyldisilazane (HMDS) can thus be obtained (Scheme 4.3) [32]. 

Lactams are named in several ways. They are named as alkanolactams by the IUPAC substitutive system, such as 3-propanolactam, 4-butanolactam, 5-pentanolactam, and 6-hexano-lactam, respectively, for the 4-, 5-, 6-, and 7-membered rings, respectively. An alternate IUPAC method, the specialist heterocyclic nomenclature system, names these lactams as 2-azetidinone, 2-pyrrolidinone, 2-piperidinone, and hexahydro-2f/-azepi n-2-one, respectively. These lactams are also known by the trivial names fl-propiolactam, a-pyrrolidone (y-butyrolactam), a-piperidone (8-valerolactam), and e-caprolactam, respectively. 

Successive addition of monomers to the end of macromolecular initiator is the usual technique for the synthesis of tailored blockcopolymers. Anionic polymerization of pivalolactone, a-pyrrolidone— and the NCA of T-methyl-D-glutamate -2 was started from the end group of a prepolymer consisting carboxylate group or acyl lactam group or amino group. Living polymer of C-capro-lactone was expected to be formed by the initiated polymerization from polymer carbanion under kinetic controlled condition. 

Sorm and Beranek39 used an intramolecular acylation in their synthesis of l-azoniumtricyclo[3.3.3.0]undecane (66). Condensation of nitromethane with acrylonitrile in the presence of an alkaline catalyst resulted in the formation of tris-(2-cyanoethyl)nitromethane (60), which afforded the triethyl ester 61 on hydrolysis followed by esterification. The ester was reduced catalytically to give a pyrrolidone (62). The derivative (62) gave rise to 8-(j8-carboethoxyethyl)-3,5-dioxo-pyrrolizidine (63) on heating. Reduction of 63 resulted in the formation of 8-(y-hydroxypropyl)pyrrolizidine (64). Replacement of the hydroxy group by bromine (65), followed by cyclization, afforded the tricyclic compound 66. 

Hoffmann and co-workers crafted the desoxyeserolin precursor 286 from the A-pyrrolidone aniline derivative 285 [325]. 

Matsumoto etal. [103] [104] used a-pyrrolidone as bridging ligand and obtained a tan colored compound having analogous structure to the platinum blue of Lippard, except that the average oxidation state was +2.50... 

A green a-pyrrolidone compound made of a mixture of [Pt4(NH3)8-(pyrl)4]5+ and [Pt4(NH3)8(pyrl)4]6+ cations with average oxidation states of 2.25 and 2.5, respectively, was also isolated and characterized by X-ray crystallography [90]. 

From a solution of the tetranuclear mixed-valence platinum complexes reported above, and in the presence of pyrazine a tetranuclear Ptm complex of formula [(N03)(NH3)2PtIII(pyrl)2PtIII(NH3)(Ju-NH2)]24+ was obtained [28]. It was composed of two a-pyrrolidonate-bridged Pt111 dimers which, in turn, were bridged by two NH2 ligands. In the Pt111 species, the intradimer Pt-Pt distance drops to 2.608 A. 

Disproportionation of [Pt225]4 has also been described recent studies on the a-pyrrolidonate [Pt2 25]4 revealed that a reaction pathway as shown in Eqn. 3, occurs very quickly in solution. 

The 02 oxidation of hydroquinone to quinone, which is very slow in the absence of a catalyst, was found to be accelerated by the addition of the a-pyrrolidonate-bridged [Pt2 5]4 [57]. The detailed kinetic investigation revealed that the [Ptn]2-species, formed according to Eqn. 1, plays a major role as the catalyst. The reaction rate of quinone formation is higher than that of 02 oxidation of [Ptn]2 to [Ptm]2, and was linear with respect to the hydroquinone concentration. Therefore, it was suggested that the quinone formation proceeds via an intermediate formed between the [Ptn]2 species and molecular oxygen (e.g., a peroxo species). The schematic mechanism is illustrated in Eqn. 10. 

When R = CH3, the imine is not reducible at the potential necessary for the cleavage of the N-N bond, whereas with R=CGH5 the imine, a derivative of propiophenone imine, is further reduced. In some cases ring closure to a pyrrolidone might occur. 

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