Synthesis of Some Thieno Analogs of the Protoberberine and Protopine Skeletons. X-Ray Crystal Structure of 9,10-Dimethoxy-5-methyl-4,5,6,7,12,13-hexahydrothieno[3,2-e][3]benzazeci n-12-one

1988 ◽  
Vol 41 (1) ◽  
pp. 111 ◽  
Author(s):  
JB Bremner ◽  
EJ Browne ◽  
LM Engelhardt ◽  
GS James ◽  
AH White

The preparation of the tetracyclic derivatives, (5) and (11), thienanalogues of the tetrahydroprotoberberine alkaloids, is described. Cyanogen bromide-induced water solvolysis of these isomeric compounds proceeded by different routes. 9,10-Dimethoxy-4,7,12,12a- tetrahydro-5H-benzo[g] thieno [3,2-a] quinolizine (11) under these conditions gave as the major product 4-(2-hydroxymethyl-4,5- dimethoxybenzyl )-4,5,6,7-tetrahydrothieno[3,2-c]pyridine-5- carbonitrile (12); no azecino derivatives were detected. By contrast such cleavage of 2,3-dimethoxy-5,8,12,12a-tetrahydro-6H- benzo [a] thieno [3,2-g] quinolizine (5) gave a major solvolytic ring- expanded product, 12-hydroxy-9,10-dimethoxy-4,5,6,7,12,13- hexahydrothieno [3,2-e][3]benzazecine-5-carbonitrile (15), and a minor elimination product, (E)-9,10-dimethoxy-4,5,6,7-tetrahydrothieno[3,2- e][3]benzazecine-5-carbonitrile (16). These last two compounds are examples of a new tricyclic ring system. From functional group interconversions of (15) was derived the N- methyl ketone (18), the first thieno analogue of the protopine alkaloid system. The crystal and molecular structure of this compound, 9,10-dimethoxy-5-methyl-4,5,6,7,12,13-hexahydrothieno[3,2-e][3] benzazecin - 12-one (18), has been determined by single-crystal X-ray methods.

1986 ◽  
Vol 39 (6) ◽  
pp. 893 ◽  
Author(s):  
JB Bremner ◽  
CL Raston ◽  
GL Rowbottom ◽  
AH White ◽  
KN Winzenberg

Reaction of the reduced pyrrolo [2,1-a] isoquinoline amine (1a) with cyanogen bromide in the presence of methanol gave the medium-ring cyanamide derivative 7,9,10-trimethoxy-2,3,4,5,6,7-hexahydro-1H-3- benzazonine-3-carbonitrile (2a). Analogous products were also obtained from reaction of the reduced 5H-oxazolo[2,3-a] isoquinoline , 2H- benzo [a] quinolizine , 2H,6H-[1,3] oxazino [2,3-a] isoquinoline and [1,4] oxazino [3,4-a] isoquinoline derivatives (1b-e), whereas the reduced 3H-oxazolo[4,3-a] isoquinoline and 5H-oxazolo[2,3-a] isoquinoline derivatives (1f) and (8) gave 1-(2,4-dioxapentyl)-6,7-dimethoxy-1,2,3,4-tetrahydroisoquinoline-2-carbonitrile (5a) and N-[2-(2-benzoyl-4,5-dimethoxyphenyl)ethyl]-N- methylcyanamide (9) respectively, the latter in low yield. The medium-sized heterocyclic derivatives (2f-h) were also obtained from cyanogen -bromide-mediated water solvolysis reactions of (1a), (1c) and (1e). The cyanamides (2a-h), (5a) and (9) have been converted into the respective tertiary amine derivatives (3a- h), (5c) and (11), with concomitant reduction of the carbonyl group in the last case. The crystal and molecular structure of 1,10,11- trimethoxy-3,4,5,6,7,8-hexahydro-1H-2,6-benzoxazecine-6-carbonitrile (2d) and 1-hydroxy-10,11-dimethoxy-1,4,5,6,7,8-hexahydro-2H-3,6- benzoxazecine-6-carbonitrile (2h) have been determined by single- crystal X-ray methods.


1983 ◽  
Vol 36 (12) ◽  
pp. 2555 ◽  
Author(s):  
EJ Browne ◽  
LM Engelhardt ◽  
AH White

Derivatives (6a-c) of the 1,4,5-benzodioxazocine ring system have been prepared in low-to-moderate yields by hydrazinolysis of {2-[2-(1,3-dioxo-1,3-dihydro-2H-isoindol-2-yl)oxyethyloxy]aryl}phenylmethanones(5a-c), and cyclization of the products at pH c. 4. Only in the case of (6b) was a trace of a cyclic dimer (7b) detected, in contrast to the analogous preparations of the 2H-1,5,6-benzodioxazonine derivatives (1a-c) where 18-membered cyclic dimers (8a-c) formed as by-products. The crystal and molecular structure of 6-phenyl-2,3-dihydro-1,4-5-benzodioxazocine (6a) has been determined by single-crystal X-ray methods.


1979 ◽  
Vol 34 (1) ◽  
pp. 48-51 ◽  
Author(s):  
Jürgen Kopf ◽  
Klaus von Deuten ◽  
Bahman Nakhdjavan ◽  
Günter Klar

Abstract The structure of 2,8-dimethyldibenzo[c,g][1,2,5,6]tetrathiaocin (1b) has been determined by X-ray methods and discussed in connection with the preferred conformations of diaryl disulfides. The compound has the anti-form I. The SS-distance is 205.8 pm, the mean CSS-angle 104.1°, and the CSS/SSC-dihedral angle 111.1°.


1988 ◽  
Vol 41 (3) ◽  
pp. 293 ◽  
Author(s):  
JB Bremner ◽  
EJ Browne ◽  
LM Engelhardt ◽  
IWK Gunawardana ◽  
AH White

Meisenheimer rearrangement of the N-oxides (4) derived from a series of 5-aryl-4-methyl-2,3,4,5-tetrahydro-1,4-benzoxazepines (3) gave rise to eight derivatives (5) of the new 2H,6H-1,5,4-benzodioxazocine ring system. Reaction of 9-methoxy-5-methyl-6-phenyl-3,4,5,6- tetrahydro-2H-1,5-benzoxazocine (6) with 3-chloroperoxybenzoic acid gave an unstable N-oxide (7). A Meisenheimer rearrangement product from (7), 10-methoxy-5-methyl-7-phenyl-2,3,4,5-tetrahydro-7 H-1,6,5- benzodioxazonine (8), the first example of this ring system, was isolated directly in moderate yield on oxidation of (6) with cooling. The crystal and molecular structure of (8) has been determined by X-ray crystallographic methods.


1988 ◽  
Vol 41 (12) ◽  
pp. 1815 ◽  
Author(s):  
JB Bremner ◽  
EJ Browne ◽  
LM Engelhardt ◽  
CS Greenwood ◽  
AH White

10-Phenyl-4,5,6,7,8,10-hexahydrothieno[3,2-g][1,4]oxazonine-6-carbonitrile (6a) and 11-phenyl-4,6,7,8,9,11-hexahydro-5H-thieno[3,2-h][1,5]oxazecine-6-carbonitrile (7a) were prepared in moderate yields by cyanogen bromide-induced ring expansion of tetrahydrothieno [2,3- c] pyridinylalkanol precursors (4a) and (5a), respectively. 1-Phenyl-1,3,4,5,6,7-hexahydro[1]- benzothieno [3,2-g][1,4]oxazonine-5-carbonitrile (6b) and 1-phenyl-3,4,5,6,7,8-hexahydro-1H- [1] benzothieno [3,2-h][1,5]oxazecine-6-carbonitrie (7b) were similarly prepared from the [1] benzothieno [2,3-c] pyridinylalkanol precursors (4b) and (5b). The medium-ring cyanamides (6b) and (7b) were converted by standard methods into their N-methyl analogues (8b) and (9b). 6-Methyl-8-phenyl-4,5,6,8-tetrahydrothieno[3,2-e][1,2] oxazepine (13) was prepared by thermal Meisenheimer rearrangement of the corresponding tertiary amine N-oxide (12). The compounds (6a, b), (7a, b) and (13) are each the first reported examples of new heterocyclic systems. The crystal and molecular structure of (6b) has been determined by X-ray crystallographic methods.


1988 ◽  
Vol 41 (4) ◽  
pp. 575 ◽  
Author(s):  
JB Bremner ◽  
EJ Browne ◽  
LM Engelhardt ◽  
BA Hyland ◽  
GS James ◽  
...  

During attempts to prepare 9,10-dimethoxy-4,7,12,12a-tetrahydro-5H- benzo [g] thieno [3,2-a] quinolizine (1), and subsequent cyanogen bromide- induced ring cleavage of this tetracyclic base, two by-products were isolated. The preparations of these two compounds are described, and their structures elucidated as 8,9-dimethoxy-1,2,3,6,11,11a-hexahydrobenzo [5,6] cyclohepta [1,2,3-cd] thieno [3,2-c]pyridine (5a), and its 1-carbonitrile derivative (5b). An N-methyl derivative (5c) has been prepared from (5a). These products (5) are the first examples of a new heterocyclic system. The crystal and molecular structure of the cyanamide (5b) has been determined by X-ray crystallographic methods.


1985 ◽  
Vol 40 (12) ◽  
pp. 1703-1710 ◽  
Author(s):  
R. Heid ◽  
H. Endres ◽  
H. J. Keller

Abstract 4.5-Dimethyl-4'.5'-ethylenedithiolotetrathiafulvalene (DIMET) was obtained by reacting 4.5- ethylenedithiolo-1.3-dithioliumtetrafluoroborate with 4.5-dimethyl- 1.3-dithiolium-tetrafluoroborate in the presence of diisopropylethylamine or triethylamine. Electrocrystallization of this donor in different solvents like dichloromethane or tetrahydrofurane (THF) and with varying supporting electrolytes, like tetrabutylammonium hexafluorophosphate, triiodide, nitrate, perrhenate or perchlorate, results in a large number of well crystallizing compounds. The crystal and molecular structure of one of the isolated solids was elucidated by X-ray methods. (C10)H10S6)2CIO4 x C4H8O, Mr = 816.66, is triclinic, P1̄ , a = 6.731(5), b - 7.632(3), c = 33.32(3) Å , α = 96.53(5), β = 92.99(6), γ = 103.13(5)°, V - 1650.7 Å3, Z = 2, dc = 1.64 gem-3, final Rw = 0.077 for 1844 observed independent reflections. Sheets of cations with an average charge of 1/2+ are separated by sheets of anions and THF solvent molecules. Intermolecular S···S contacts result in two-dimensional physical properties. Electrical conductivity and thermopower measurements indicate two broad phase transitions at around 200 K and 80 K


1978 ◽  
Vol 56 (2) ◽  
pp. 179-188 ◽  
Author(s):  
Colin James Lyne Lock ◽  
Graham Turner

The crystal structure of µ-oxobis(cis-dichloro-cis-di(pyridine)-trans-oxorhenium(V)), ORe(C5H5N)2Cl2•O•Re(C5H5N)2Cl2O bas been studied by single crystal X-ray methods. The crystals were orthorhombic with lattice parameters a = 15.367(2), b = 10.283(2), c = 16.685(2) Å. The space group was Pna21 and there were four formula weights per unit cell. A total of 3339 reflections, of which 2990 were observed, were examined, and the structure refined by full matrix least squares (treating the pyridine rings as groups) to an R2 value of 0.0449. The dimer had a roughly rectilinear O—Re—O—Re—O backbone with pairs of chlorine atoms and pyridine molecules arranged cis in each half of the dimer. The two halves of the dimer were arranged such that the pairs of cis atoms in one half were rotated about the Re(1)–Re(2) axis almost 113 ° when compared to the corresponding pair in the other half. Important bond lengths (Re—O(terminal), 1.715(16), 1.764(16); Re—O(bridging), 1.943(16), 1.903(16); Re—Cl, 2.356(5)–2.390(5); Re—N, 2.116(16)–2.180(16)) were close to previously observed values. The molecule was markedly disturbed from the idealized structure and this was caused by intramolecular non-bonded interactions.


1987 ◽  
Vol 40 (8) ◽  
pp. 1399 ◽  
Author(s):  
S Kulkarni ◽  
MR Grimmett ◽  
LR Hanton ◽  
J Simpson

4(5)- Bromo - and - iodo-imidazoles, activated by an adjacent nitro substituent, undergo nucleophilic displacement with methoxide, phenoxide , cyclic secondary chines and cyanide. The regiochemistry of the reactions of 5-iodo-4-nitroimidazole with methoxide has been confirmed by spectroscopic and X-ray methods, and a number of erroneous structures from the literature have been revised. Some apparently anomalous reactions of methoxide with 5-halo-1,2-dimethyl-4- nitroimidazoles, and of cyanide with 4-halo-1-methyl-5-nitroimidazole have been noted. The crystal and molecular structure of 5-methoxy-1-methyl-4-nitroimidazole has been determine: by direct methods. Crystals are monoclinic, P21/c, a 10.929(3), b 8 899(2), c 7.290(2) �; β 92.87(2)�; Z 4. The structure was refined to R = 0.095 for 818 reflections (I > 2σI).


1989 ◽  
Vol 54 (1) ◽  
pp. 160-165 ◽  
Author(s):  
František Pavelčík ◽  
Karol Havetta ◽  
Jaroslav Páterek

The structure of the title compound was determined by the method of X-ray diffraction of single crystals. The substance crystallizes in the P21/c monoclinic space group. The structure was refined by the least squares method to R = 0.044 on the basis of 2 076 observed reflections. It was found that this compound is not a dicarboxylic acid but rather an intramolecularly cyclized lactam. The hydrogen phosphonato functional group participates in the betain form, while the carboxyl group is not ionized. The conformation of the six-membered oxopiperazine ring is similar to that of cyclohexane in which the peptidic group plays a similar role to the double bond.


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