Halide Substituents Research Articles

Synthesis and biological evaluation of 2-styrylquinazolin-4(3H)-ones, a new class of antimitotic anticancer agents which inhibit tubulin polymerization

A novel series of 2-styrylquinazolin-4(3H-ones which inhibited tubulin polymerization and the growth of L1210 murine leukemia cells was discovered. Extensive structure-activity relationship studies suggest that the entire quinazolinone structure was required, but activity was further enhanced by halide or small hydrophobic substituents at position 6. These analogues did not substantially interfere with the binding of radiolabeled colchicine, vinblastine, or GTP to tubulin and weakly stimulated GTP hydrolysis uncoupled from polymerization. Several analogues have shown in vivo tumor growth inhibitory activity in the L1210 leukemia model, with the lead compound 5o exhibiting good antitumor activity against murine solid tumors as well as human tumor xenografts.

Conformational interactions between a phenyl ring and a side-chain halide substituent: A 1H NMR and molecular mechanics study of some 2-aryl-1-halopropanes

1H NMR data are reported for a series of 2-aryl-1-halopropanes. Vicinal coupling constants in the CH 2CH—fragment show that the rotamer populations about the CC bond are sensitive to para substituents. The ratio of anti:gauche aryl/halide conformers is greatest when the para substituent is the electron-donating ethyl group and least when it is the strongly electron-withdrawing nitro group. This points to a non-steric conformational interaction involving the ring and the sidechain heteroatom. Comparison of the empirical results with conformational preferences predicted from molecular mechanics calculations using the COSMIC force field suggests that the interaction serves to enhance the population of the anti arrangement.

Lewis-base adducts of Group 1B metal(I) compounds. Part 18. Stereo-chemistries and structures of the 1 : 1 neutral complexes of Cu I X with 1,10-phenanthroline (X = I) or 2,9-dimethyl-1,10-phenanthroline (X = I, Br, or Cl)

Single-crystal X-ray structure determinations have been carried out at 295 K on the compounds [Cul(phen)]·5MeOH (1)(phen = 1,1 0-phenanthroline), [Cul(dmphen)](2), [CuBr(dmphen)](3), and [CuCl(dmphen)](4)(dmphen = 2,9-dimethyl-1,10-phenanthroline). Crystals of (1) are monoclinic, P21/n, a= 10.659(3), b= 23.585(9), c= 10.487(3)A, β= 91.34(2)°, Z= 8; for N0= 2 457 independent ‘observed’ diffractometer reflections, R= 0.034. Crystals of (2) are monoclinic, C2/c,a= 19.025(6), b= 8.489(3), c= 17.376(5)A, β= 108.27(2)°, Z= 8; N0= 1 582, R= 0.035. Crystals of (3) are isomorphous with (2), a= 18.497(6), b= 8.398(2), c= 17.419(5)A, β= 110.14(2)°; N0= 1 786, R= 0.040. Crystals of (4) are monoclinic, P21/n, a= 10.133(4), b= 18.388(5), c= 6.729(1)A, β= 94.31(2)°, Z= 4; N0= 889, R= 0.044. In (1)–(3), the species is a di-p-halogeno-bridged dimer with four-co-ordinate copper atoms. For (1), Cu–I are 2.589(1)–2.632(1)A with Cu–N 2.078(6)–2.103(6); Cu ⋯ Cu is 2.609(2) and I ⋯ I, 4.454(2)A. In (2), Cu–I are 2.673(1), 2.563(1), Cu–N, 2.094(6), 2.092(5); Cu ⋯ Cu is 3.024(2) and I ⋯ I, 4.276(1)A. In (3), Cu–Br are 2.400(1), 2.559(1), Cu–N, 2.083(5), 2.085(4)A; Cu ⋯ Cu is 3.097(1) and Br ⋯ Br, 3.876(1)A. Complex (4) is mononuclear with the copper atom pseudo-trigonally planar co-ordinated by the bidentate aromatic ligand [Cu–N 2.060(6) and 2.057(5)A] and the halide [Cu–Cl, 2.126(2)A]. The role of the ligand and halide substituents on the complexity of the complex is examined.

Negative ion mass spectra of some classes of metal carbonyl halides

The negative-ion mass spectra at 70 eV of the compounds Re(CO) 5X (X = Cl, Br, I), Mn(CO) 5X (Br, I), Re 2(CO) 8X 2 (X = Cl, Br, I), Mn 2(CO) 8Br 2 and Rh 2(CO) 4X 2 (X = Cl, Br, I) are reported. The negative molecular ions are absent and the current is mainly transported by fragments due to the loss of carbonyl groups. In the spectra of the bimetallic compounds a rather high intensity is displayed by ionic species containing the two halide substituents. The variations in the ionic abundances are related to the change of the metal-CO bond strength, while the nature of X seems to play a minor role.

Photoelectron spectroscopic studies of some nitrosyl and nitryl halides and nitric acid

The He(I) photoelectron spectra of the compounds FNO, ClNO, BrNO, FNO 2 and ClNO 2 have been recorded on an instrument specifically designed to study reactive and short-lived species. The spectrum of HNO 3 (isoelectronic with the nitryl halides) is included for comparison. The spectra of the nitrosyl halides are interpreted by reference to SCF-MO calculations, by correlation with the known levels of NO, and by consideration of the electronic effect of the halide (X) substituent. The resulting assignments are in accord with weak bonding between the X and NO moieties. The assignments for the nitryl halides and nitric acid are assisted by correlation with the known levels of NO 2, by consideration of the electronic effects of the X substituent, by an analysis of vibrational structure, and by CNDO type MO calculations. On the basis of our assignments for these latter molecules we propose a reassignment of the photoelectron spectrum of CH 3NO 2.

Production of organometallic polymers by the interfacial technique. XXX. Synthesis of oligomeric ferrocene containing tin polyesters

AbstractThe synthesis of ferrocene containing polyesters is reported along with particular reaction and substituent dependencies. Synthesis is rapid being completed within 30 seconds. Yield increases when either reactant is in excess. Yield decreases for alkyl magnified image substituents on the tin in the order methyl > ethyl > t‐butyl > n‐octyl and I > Br > Cl for halide substituents on tin.

The use of diborane and deuterodiborane in the synthesis of isotopically labeled amines

AbstractThe use of diborane has facilitated the preparation of several amines labeled with carbon‐14 or nitrogen‐15 by reduction of the corresponding labeled nitrile or amide. Its use was particularly advantageoue in the presence of aromatic halide substituents. Deuterodiborane, formed in situ from sodium borodeuteride and dimethyl sulfate, has been shown to be useful in the synthesis of 1, 1‐dideuteroamines.Amines prepared in this study include nortriptyline labeled with nitrogen‐15, deuterium or both,; 2‐(o‐chlorophenoxy) ethyl‐N‐cyclopropylamine as the 1‐14C‐derivative and as the 1, 1‐dideutero derivative; 2‐(2, 4‐dichloro‐6‐phenylphenoxy) ethyl‐1‐14C amine and its 2‐chloro‐6‐phenyl analog; and 3‐aminomethyl14C‐pyridine.