Synthesis of Thieno[2,3-g][1,4]oxazonine and Thieno[2,3-h][1,5]oxazecine derivatives by cyanogen-bromide-induced ring expansion

1984 ◽  
Vol 37 (5) ◽  
pp. 1043 ◽  
Author(s):  
JB Bremner ◽  
EJ Browne ◽  
V Chohan ◽  
BF Yates
Keyword(s):  
Cyanogen Bromide ◽  
Ring Expansion ◽  
Standard Methods ◽  
Methyl Derivatives ◽  
Derivatives Of ◽  
Medium Ring

4-Phenyl-4,6,7,8,9,10-hexahydrothieno[2,3-g][1,4]oxazonine-8-carbonitrile (5a) and the analogous 4-phenyl-6,7,8,9,10,11-hexahydro-4H-thieno[2,3-h][1,5]oxazecine-9-carbonitrile (5b) were preparedin moderate yields by cyanogen bromide-induced ring expansion of the appropriate ω-(tetrahydrothieno[3,2-c]pyridyl)alkan-1-ol precursors (3). N-Methyl derivatives of these new fused medium-ring heterocyclic systems were prepared by standard methods.

Preparation of Thieno[3,2-e][1,2]oxazepine, Thieno and [1]Benzothieno-[3,2-g][1,4]oxazonine, and 5H-Thieno and 1H-[1]Benzothieno-[3,2-h][1,5]oxazecine Derivatives by Ring Expansion Methods. X-Ray Crystal Structure of 1-Phenyl-1,3,4,5,6,7-hexahydro[1]benzothieno-[3,2-g][1,4]oxazonine-5-carbonitrile

1988 ◽  
Vol 41 (12) ◽  
pp. 1815 ◽  
Author(s):  
JB Bremner ◽  
EJ Browne ◽  
LM Engelhardt ◽  
CS Greenwood ◽  
AH White
Keyword(s):  
Molecular Structure ◽  
Crystal Structure ◽  
Tertiary Amine ◽  
Cyanogen Bromide ◽  
Crystal And Molecular Structure ◽  
Ring Expansion ◽  
Standard Methods ◽  
X Ray ◽  
Medium Ring

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.

Synthesis of some 2,5-benzoxazocine and 2,6-benzoxazonine derivatives from ω-(Dihydroisoindol-2-yl)alkanol precursors by means of cyanogen bromide

1982 ◽  
Vol 35 (11) ◽  
pp. 2307 ◽  
Author(s):  
JB Bremner ◽  
N Thirasasana
Keyword(s):  
Cyanogen Bromide ◽  
Ring Systems ◽  
Derivatives Of ◽  
Medium Ring ◽  
Moderate Yield

Reaction of cyanogen bromide with 2-(1-phenyl-2,3-dihydro-1H-isoindol-2-yl)ethanol (5a) gave 1-phenyl-3,4,5,6-tetrahydro-1H-2,5-benzoxazocine-5-carbonitrile (6a) in a low to moderate yield. Similarly, 3-(1-phenyl-2,3-dihydro-1H-isoindol-2-yl)propan-1-ol (5c) gave 1-phenyl-1,3,4,5,6,7-hexa-hydro-2,6-benzoxazonine-6-carbonitrile (6c). The analogous 1-(4-methoxyphenyl) derivatives of both medium ring systems were also prepared, and some mechanistic aspects of the results are discussed. Conversion of (6a) into the analgesic, Nefopam,is described.

Synthesis of 1H-[1]Benzothieno[3,2-d]azonine and [1]Benzothieno[3,2-d]azecine Derivatives

1985 ◽  
Vol 38 (5) ◽  
pp. 765 ◽  
Author(s):  
EJ Browne
Keyword(s):  
Aqueous Medium ◽  
Magnesium Oxide ◽  
Cyanogen Bromide ◽  
Functional Group ◽  
Ring System ◽  
Cyclic Ketones ◽  
Phenyl Derivative ◽  
E And Z Isomers ◽  
Derivatives Of ◽  
Medium Ring

Derivatives of two new [1] benzothieno medium-ring heterocyclic systems have been prepared by ring degradation using cyanogen bromide-induced solvolysis of tetracyclic precursors. Reaction of a hexahydro -[1] benzothieno [3,2-g] indolizine (4a) and a hexahydro-2H-[1] benzo-thieno [2,3-a] quinolizine (4b) with cyanogen bromide and magnesium oxide under solvolytic conditions yielded the hexahydro-1H-[1] benzothieno [3,2-d] azonines (5a) and (6a) and the octahydro -[1] benzothieno [3,2-d] azecines (5b) and (6b), respectively. Functional group interconversions of these medium-ring systems are described, including oxidations to the cyclic ketones (7) and (9). The 11b-phenyl derivative (13) of (4a) reacted under similar conditions to give both solvolysis (14) and (16) and elimination (15) medium-ring products, the ratios depending on the solvent. By contrast the analogous 9a-phenylthienoindolizine derivative (17) under these conditions gave only the medium-ring elimination product (18) in aqueous medium, and only the equivalent solvolysis product in methanol. Both the thieno and [1] benzothienoazonine elimination products (18) and (15) appear to be mixtures of E and Z isomers. The [1] benzothieno [3,2-g] indolizine bases (4a) and (13) are the first reported examples of this ring system.

scholarly journals β-Enolization in α-phenyl-α,α′,α′-trimethylcycloalkanones

1992 ◽  
Vol 70 (5) ◽  
pp. 1274-1280 ◽  
Author(s):  
Wendy Sifton ◽  
J. B. Stothers ◽  
Shirley E. Thomas
Keyword(s):  
Secondary Alcohol ◽  
Ring Expansion ◽  
Methyl Groups ◽  
Proton Abstraction ◽  
Phenyl Proton ◽  
Methyl Derivatives ◽  
Cyclic Systems ◽  
A Minor ◽  
Acyclic Ketones ◽  
Derivatives Of

Ring expansion through β-proton abstraction from α-methyl groups has been observed for the α-phenyl-α,α′,α′,-tri-methyl derivatives of cyclopentanone and cyclohexanone upon treatment with t-BuO−/t-BuOH/185 °C. This contrasts with the lack of rearrangement found for the α,α,α′,α′-tetramethyl derivatives but is analogous to the behavior of some α-phenyl acyclic ketones. However, this process is reversible in the cyclic systems, but irreversible in the acyclic cases. For all of these α-phenyl substituted ketones, rearrangement is in competition with Haller–Bauer type cleavage. In the cyclic systems, a minor process was observed whereby some of the ring-expanded product is reduced to the corresponding secondary alcohol but there was no evidence of rearrangement through γ-enolate formation involving phenyl proton abstraction, which is a minor process in the α-phenyl acyclic systems.

Synthesis of 4H-Thieno[2,3-d]azonine and Thieno[2,3-d]azecine derivatives

1984 ◽  
Vol 37 (2) ◽  
pp. 367 ◽  
Author(s):  
EJ Browne
Keyword(s):  
Magnesium Oxide ◽  
Cyanogen Bromide ◽  
Functional Group ◽  
Cyclic Ketones ◽  
Ring Systems ◽  
Phenyl Derivative ◽  
Derivatives Of ◽  
Medium Ring

Derivatives of two new thieno medium-ring heterocyclic systems have been prepared by ring degradation using cyanogen bromide-induced solvolysis of tricyclic bases. Reaction of a hexahydrothieno[2,3-glindolizine (4a) and a hexahydro-7H-thieno[3,2-a]quinolizine (4b) with cyanogen bromide and magnesium oxide under solvolytic conditions yielded derivatives of hexahydro-4H-thieno[2,3-d]azonine (5a) (6a) and octahydrothieno[2,3-d]azecine (5b) (6b), respectively. Functional group interconversions of these medium-ring systems are described, including oxidations to cyclic ketones. The 9a-phenyl derivative of (4a) reacted similarly. By contrast 10b-phenyl derivatives (10a,b) of a hexahydropyrrolo[2,1-a]isoquinoline reacted under these conditions to give medium-ring elimination products, derivatives of tetrahydro-1H-3-benzazonines.

Synthesis of Benzo[D]Thieno[2,3-G]Azecine and Benzo[D][1]Benzothieno[2,3-G]Azecine Derivatives

1986 ◽  
Vol 39 (5) ◽  
pp. 783 ◽  
Author(s):  
EJ Browne
Keyword(s):  
Magnesium Oxide ◽  
Cyanogen Bromide ◽  
Functional Group ◽  
Cyclic Ketones ◽  
Ring Systems ◽  
Derivatives Of ◽  
Medium Ring

Derivatives of two new diannulated azecine systems have been prepared by ring degradation of precursor bases with cyanogen -bromide-induced solvolysis. Reaction of a tetrahydro-5H-benzo[h] thieno [2,3,-a] quinolizine (5a) and a tetrahydro-7H-benzo[h][1] benzothieno [2,3-a] quinolizine (5b) with cyanogen bromide and magnesium oxide under solvolytic conditions yielded derivatives of a hexahydrobenzo [d] thieno [2,3-g] azecine (6a) and a hexahydrobenzo [d][1] benzothieno [2,3-g] azecine (6b), respectively. Functional group interconversions of these medium-ring systems were performed, including oxidations to cyclic ketones. The 5H-benzo[h] thieno [2,3-a] quinolizine and 7H-benzo[h] [l] benzothieno [2,3-a] quinolizine bases (5a) and (5b) are the first reported examples of these ring systems.

Physical Properties of TCNQ Salts with N-Methyl Derivatives of Pyridine

1982 ◽  
Vol 85 (1) ◽  
pp. 257-263 ◽  
Author(s):  
A. Graja ◽  
M. Przybylski ◽  
B. Butka ◽  
R. Swietlik
Keyword(s):  
Physical Properties ◽  
Methyl Derivatives ◽  
Derivatives Of

Methyl derivatives of furan

1974 ◽  
Vol 39 (11) ◽  
pp. 3109-3116 ◽  
Author(s):  
J. Šrogl ◽  
M. Janda ◽  
I. Stibor ◽  
V. Skála ◽  
P. Trška ◽  
...  
Keyword(s):  
Methyl Derivatives ◽  
Derivatives Of
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