Analogous Amides Research Articles

Intramolecular Vilsmeier processes: a new route to cyclopenta[b]- and cyclohexa[b]-fused quinolines by cyclisation of adipic and pimelic bis-amides

Symmetrical and unsymmetrical bis-amides derived from adipic and pimelic acid and secondary amines react in POCl3 solution to give the title compounds by way of a Vilsmeier reagent–α-chloro enamine interaction. Adipanilide and pimelanilide only cyclise with added PCl5. However the bis-N-substituted derivatives (N-methyl or N-phenyl) of adipanilide and pimelanilide give quinolinium salts in good yield. Unsymmetrical amides with an N-substituted anilide at one end and an aliphatic unit at the other only proceed as far as the intermediate stage, giving 1,2-disubstituted cyclo-pentanes or -hexanes. Analogous amides derived from suberic and sebacic acid do not give quinolinium salts but instead give complex mixtures.

Selective ion—molecule reactions of lactams with dimethyl ether ions

The ion—molecule reactions of dimethyl ether ions CH 3OCH + 2 and (CH 3OCH 3)H +, and four- to seven-membered ring lactams with methyl substituents in various positions were characterized by using a quadrupole ion trap mass spectrometer and a triple-quadrupole mass spectrometer. In both instruments, the lactams were protonated by dimethyl ether ions and formed various combinations of [M + 13] +, [M + 15] +, and [M + 45] + adduct ions, as well as unusual [M + 3] + and [M + 16] + adduct ions. An additional [M + 47] + adduct ion was formed in the conventional chemical ionization source of the triple-quadrupole mass spectrometer. The product ions were isolated and collisionally activated in the quadrupole ion trap to understand formation pathways, structures, and characteristic dissociation pathways. Sequential activation experiments were performed to elucidate fragment ion structures and stepwise dissociation sequences. Protonated lactams dissociate by loss of water, ammonia, or methylamine; ammonia and carbon monoxide; and water and ammonia or methylamine. The [M + 16] + products, which are identified as protonated lactone structures, are only formed by those lactams that do not have an N-methyl substituent. The ion—molecule reactions of dimethyl ether ions with lactams were compared with those of analogous amides and lactones.

Reaction of diimide compounds with diglycidyl ether of 4,4′‐dihydroxybiphenyl

AbstractNew esterimide and ketoimide polymers containing a biphenyl group have been synthesized and characterized by spectral techniques. Their thermal properties have been studied by thermogravimetric (TGA) measurements, showing a different stability with regard to the imide structure. The analogous amide imide compounds have been tested as monomers, but their polymerization has not taken place as we expected and side reactions have been detected by 13C‐NMR spectroscopy.

Geometries and rotation barriers of the simplest acylphosphines: Ab initio gradient calculations of the structures of formylphosphine and acetyldimethylphosphine

Using ab initio gradient calculations at the Hartree—Fock level, the structures of formylphosphine and acetyldimethylphosphine were determined as a function of the torsional angle around the central PC AC bond. Split valence-shell basis sets, augmented by a set of polarization d-functions on the phosphorus atom, were used. For both molecules, the existence of a single total-energy minimum corresponding to the amide-type conformation ( C 1 symmetry) was demonstrated. Full optimization of all the geometrical parameters was made at the stable conformation and at the transition states for internal rotation of the acyl group. The rotation barriers in the acylphosphines are considerably lower than in the analogous amides. In contrast to the latter, the steric factors in acylphosphines are relatively more important in their effect on the potential-curve shape as compared with electronic factors. Although the calculated geometric parameters of the acylphosphines are indicative of a certain contribution of p — π conjugation in the stable conformation, the magnitude of the effect is quite small. In all the computed acetyldimethylphosphine conformations, the PC Ac bond length is greater than that of PC Me. A similar regularity was earlier noted in analysis of experimental data on carbon—halogen bond lengths.

Studies on organophosphorus compounds XXVI. Synthesis and 13C NMR spectra of N,N‐dialkyl thioamides

AbstractBy a new thiation reagent,1, 4, 11 the dimer of p‐methoxyphenylthionophosphine sulfide, 3, a series of thioamides have been prepared in almost quantitative yields from the corresponding amides, Carbon‐13 NMR spectra of tertiary thioamides of formic, acetic, trifluoroacetic, propionic and butyric acids have been completely assigned with the aid of extensive double resonance and shift reagent experiments and the data obtained have been compared with those of the analogous amides.8 Also a linear relation between the 13C chemical shifts of CS of the thioamides and CO of the corresponding amides has been found by a least square linear regression analysis: δ(CS) = 1.60° (CO)−72.3.

Structure investigation of the 2-arylamino-2-thiazoline and the analogous thiazine amides XIV: crystal structure of 2(2,6-dimethyl-phenyl)-imino-3(2-chlorobenzoyl)-thiazolidine

Structure investigation of the 2-arylamino-2-thiazoline and the analogous thiazine amides XIV: crystal structure of 2(2,6-dimethyl-phenyl)-imino-3(2-chlorobenzoyl)-thiazolidine

Specificity in Ceramide Biosynthesis from Long Chain Bases and Various Fatty Acyl Coenzyme A's by Brain Microsomes

The formation of ceramide from long chain bases and 14C-acyl coenzyme A's by a mouse brain microsomal preparation was investigated. Activity of the acyl-CoA:long chain base N-acyltransferase was measured as a function of time, acyl-CoA concentration, amount of amine, and microsomal protein concentration. The rate and extent of conversion of stearoyl-, lignoceroyl-, palmitoyl-, and oleoyl-CoA to ceramide were in the ratio of about 60:12:3:1, respectively. Since this ratio strongly resembles the relative distribution of these fatty acids in brain sphingolipids, we suggest that the transferase plays an important role in controlling the observed distribution. There was some specificity with respect to the base, particularly with lignoceroyl-CoA, which reacted somewhat better with dihydrosphingosine than with sphingosine. The keto analogue of dihydrosphingosine acted as an acceptor, with stearoyl-CoA, to form ketoceramide. The microsomal preparation also converted the acyl-CoAs to free fatty acid and polar lipid during the incubations. Ceramide synthesis was found to occur primarily in microsomal membranes, but ceramide hydrolase was rather widely distributed in subcellular fractions; its highest specific activity was in the lysosome-rich fractions. Free stearic acid did not react to form ceramide, yet it could react with ethanolamine to form the analogous amide. From these and related considerations, we conclude that the synthetic capability of ceramide hydrolase has little or no physiological significance.

Synergistic effects of some compounds related to 2‐diethylaminoethyl 2,2‐diphenyl‐n‐pentanoate (SKF 525A) on the insecticidal activity of pyrethrins

AbstractA number of compounds related to SKF 525A were tested for synergism with pyrethrins, using Lesser Mealworm beetles, Alphitobius laevigatus, and houseflies, Musca domestica, as test insects. SKF 525A had previously been shown to be active, whereas 2,2‐diphenyl‐n‐pentanoic acid and 2‐diethylaminoethanol were inactive. Several active compounds resulted from esterification of 2‐diethylaminoethanol with diphenylacetic acid and 1‐substituted diphenylacetic acids. Most modifications of the alcoholic moiety of active 2‐diethylaminoethyl esters destroyed activity. Active compounds resulted when a 2‐diethylamino group was joined to a diphenylmethyl group through an ester, ketone or ether linkage, but the analogous amide was inactive. 2‐Diethylaminoethyl piperonylate probably owed its activity to its piperonyl group. None of the compounds investigated approached piperonyl butoxide in synergistic activity.