C-Caprolactam

Natriumalanat7, Natrium-bis-[2-methoxy-athoxy]-dihydrido-aluminat8 und Dialkyl-aluminiumhydride reduzieren Lactame ahnlich wie Lithiumalanat zu cyclischen Aminen. Mit den beiden letzteren Hydriden kann auch in Benzol/Kohlen-wasserstoff gearbeitet werden. Eine Arbeitsvorschrift zur Herstellung von Azepan aus c-Caprolactam durch Reduktion mit Diathyl-aluminiumhydrid ist in ds. Handb., Bd. XIII/4, S. 220, mit Bis-[2-methyl-propyl]-aluminiumhydrid in der Lit. angegeben9. 

In analogy, Ugi et al. reported on a lactam formation by running a one-pot three components reaction the condensation of L-lysine 7, isobutyraldehyde and methyl isocyanide led to the corresponding a-amino-c-caprolactam 9, but the yield was not given. The authors presumed either a nucleophilic substitution of the ester 8 as the primary Ugi product by the amino function of the side chain or, alternatively, the nucleophilic attack of the NH2-group on an intermediately formed 0-acylamide and a subsequent rearrangement (Scheme 1) [4]. 

Under forced conditions, the reductive cyclization of a 6-oximeester at 150 °C gave a simple c-caprolactam in about 60% yield [5a]. A preliminary chemoen-... 

Activated carboxylic acids served as versatile precursors in lactam synthesis. Robl described some a-amino-c-alkyl-c-caprolactam syntheses, Eqs. (4-7)] [12]. Ring closure was induced after an EDC/HOBt activation of the acid function of 31 to form the 6-propyllactam 32 in 51 % yield, Eq. (4). The cyclization of... 

A regio- and stereoselective Beckmann rearrangement utilized diastereose-lective host guest interactions of the inclusion complexes 225 and 228 in a solid state reaction. Initially, a 1 1 mixture of the chiral host 223 and the racemic oximes 224 and 227, respectively, was treated with ultra sound in the solid state to induce the optical resolution. Then H2SO4 was added to start the Beckmann rearrangement, the corresponding c-caprolactams 226 and 229 were isolated in 68 % and 64 % yields and ee of about 80 % and 69 % (determined by HPLC analysis on chiracel OC) (Scheme 43) [46]. 

It was reported earlier that even dialkyl sulphides are efficiently oxidized to sulphoxides without a concomitant C—S bond cleavage by NBS or N-chlorosuccinimide (NCS) when the reaction is performed in anhydrous methanol at low temperature . iV-Chloro-Nylon-6,6 in methanol-water or dioxane-water and iV-bromo-c-caprolactam in water or alcohols were also used successfully for oxidation of sulphides. 

The one-base mechanism is characterized by the retention of the substrate-derived proton in the product (internal retum).30) With this criterion, reactions catalyzed by a-amino-c-caprolactam racemase,323 amino acid racemase of broad specificity from Pseudomonas striata333 have been considered to proceed through the one-base mechanism. However, such internal returns were not observed in the reactions of alanine racemases from K coli B,33) B. stearothermophilus,263 and S. typhirmaium (DadB and /1/r).263 The internal return should not be observed in the two-base mechanism, because the base catalyzing the protonation to the intermediate probably obtains the proton from the solvent. But the failure of the observation of the internal return can be also explained by the single-base mechanism in which exchange of the proton abstracted from the substrate a-carbon with the solvent is much faster than its transfer to the a-carbanion. Therefore, lack of the internal return does not directly indicate the two-base mechanism of the alanine racemase reaction. 

Univ. Tokyo 6, 137-9 (1952). IR dichroism succinic acid, c-caprolactam. 

IR association of amides in CCI4, iV-methylacetamide, 6-valerolactam, c-caprolactam, 3/<. 

The results diown in Fig. 18 and 19 show conclusively that thermodynamic equilibria between monomeric c-caprolactam and polymeric nylon-6 can be set up in the solid polymer well below its melting point. Similar monomer concentrations are obtained by heating at 459 K, for over 30 days, starting with (i) polymer containing 8.2% w/w monomer, (ii) polymer containing no monomer and (iii) monomer alone. 

Triaryl isocyanurates are useful as activators for the continuous anionic polymerization and postpolymerization of c-caprolactam to nylon-6 possessing a low unreacted monomer content and a highly stable melt viscosity [93]. Although a wide variety of catalysts for the trimerization of aryl isocyanates to triaryl isocyanurates are known, purity of trimerized product (a requirement for nylon of good quafity) is problematic and purification results in product... 

Collision induced dissociation (B/E) mass spectra of (a) ion at m/z 71 from Nylon 3 pyrolysis (b) acrylamide (c) caprolactam. (Reprinted from Ref. 46, Copyright 1986, with permission from Elsevier Science.)... 

Hydrolytic polymerizations are the smoothest of all three types of polymerization reactions, because the growing species are less activated than in either cationic or anionic polymerizations. Many commercial processes utilize it in c-caprolactam polymerizations. Formation of irregular structures, however, and even crosslinked material was detected. In addition, at elevated temperatures deamination and decarix)xylation of polycaprolactam can take place. Such reactions can result in formations of ketones and secondary amine groups The ketones, in turn, can react with amines and form Schiff bases. This leads to branching and crosslinking. 

CAS 105-60-2 EINECS/ELINCS 203-313-2 Synonyms Aminocaproic lactam 6-Aminohexanoic acid cyclic lactam 2-Azacyclophetanone 6-Caprolactam c-Caprolactam... 

However, another approach to find the suitable catalyst for the conversion of cyclohexanone oxime to caprolactam in order to completely eliminate the salt formation has been reported by Sumitomo, of Japan. They reported the use of a solid high-silica zeolite catalyst (ZSM-5) for the gas-phase rearrangement of cyclohexanone oxime at 350 °C. Caprolactam is produced with 95% selectivity at 100% oxime conversion. 

ClBH27CIN2O4, c-Caprolactam - 4-chlororesorcinol C18H28N4O6, l8-Crown-6 - malononitrile, 43B, 412 C18H42I4K2N6O6, N-Methylacetamide-potassium iodide-potassium triiodide complex, 30B, 257... 

The presence of complexed LiCl in our polymerization conditions has been further supported by a detailed study of the phase diagram for the binary c-caprolactam-LiCl system. Homogeneous solutions (melts) of LiCl-caprolactam mixtures with different salt content were prepared at 120 C and cooled down. Heating and cooling cycles were followed by DSC. The resulting equilibrium diagram is shown in Figure 3. An eutectic composition of about 5 mole... 

Formation of adducts between LiCl and c-caprolactam or pyrro-lidone having 1 4 composition was observed by solubility and phase diagram studies. Specific interactions between LiCl and the lactams were also evidenced in the amorphous state, and in the absence of water, by infrared spectroscopy. 

Poly(vinyl butyral), maleated in coatings, 505 Poly(iV-vinyl-c-caprolactam-alt-MA), 335, 336, 399, 400... 

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