N,N-Dialkyl-N'-Chlorosulfonyl Chloroformamidines in Heterocyclic Synthesis. Part VIII. Novel Pyrazolo-Fused Oxathiadiazines and Thiatriazoles

2010 ◽  
Vol 63 (4) ◽  
pp. 659 ◽  
Author(s):  
Craig M. Forsyth ◽  
Craig L. Francis ◽  
Saba Jahangiri ◽  
Andris J. Liepa ◽  
Michael V. Perkins ◽  
...  
Keyword(s):  
Recent Work ◽  
Major Product ◽  
Ring System ◽  
Heterocyclic Synthesis ◽  
Ring Systems ◽  
The Core ◽  
Derivatives Of

N,N-dialkyl-N′-chlorosulfonyl chloroformamidines 1 reacted with pyrazol-3-ones 2 under a variety of conditions to give pyrazolo[2,3-e][1,2,3,5]oxathiadiazine dioxides 3 and pyrazolo[3,2-b][1,4,3,5]oxathiadiazine dioxides 5, and frequently, one or both of pyrazolo[1,2-b][1,2,3,5]thiatriazole 1,1,5-trioxides 4 and 1,1,7-trioxides 6. In all reactions, the pyrazolo[3,2-b][1,4,3,5]oxathiadiazine 5 was the major product, with the pyrazolo[2,3-e][1,2,3,5]oxathiadiazine 3 being a significant product in the absence of base. Prior to our recent work, the core ring systems of compounds 3 and 5 had not been reported and compounds 4 and 6 are new derivatives of a rare ring system.

The Meisenheimer Rearrangement in Heterocyclic Synthesis. IV. Derivatives of the 2H,6H-1,5,4-Benzodioxazocine and 7H-1,6,5-Benzodioxazonine Ring Systems: X-Ray Crystal Structure of 10-Methoxy-5-methyl-7-phenyl-2,3,4,5-tetrahydro-7H-1,6,5-benzodioxazonine

1988 ◽  
Vol 41 (3) ◽  
pp. 293 ◽  
Author(s):  
JB Bremner ◽  
EJ Browne ◽  
LM Engelhardt ◽  
IWK Gunawardana ◽  
AH White
Keyword(s):  
Molecular Structure ◽  
Crystal Structure ◽  
Crystal And Molecular Structure ◽  
Ring System ◽  
Heterocyclic Synthesis ◽  
Rearrangement Product ◽  
Ring Systems ◽  
X Ray ◽  
Derivatives Of ◽  
Moderate Yield

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.

N,N-Dialkyl-N′-Chlorosulfonyl Chloroformamidines in Heterocyclic Synthesis. Part XIV. Synthesis and Reactivity of the New Benzo[4,5]imidazo[1,2-b][1,2,6]thiadiazine Ring System

2018 ◽  
Vol 71 (1) ◽  
pp. 58 ◽  
Author(s):  
Dylan Innes ◽  
Michael V. Perkins ◽  
Andris J. Liepa ◽  
Craig L. Francis
Keyword(s):  
Medicinal Chemistry ◽  
Ring System ◽  
Heterocyclic Synthesis ◽  
Alkyl Derivatives ◽  
Regioselective Reactions ◽  
Novel Scaffold ◽  
Derivatives Of ◽  
Related Compounds

N,N-Dialkyl-N′-chlorosulfonyl chloroformamidines 1 underwent regioselective reactions with the 1,3-NCC bis-nucleophilic 1H-benzimidazole-2-acetonitriles 4 and related compounds to produce benzo[4,5]imidazo[1,2-b][1,2,6]thiadiazine dioxides 6, 9, 12, and 14, representatives of a new ring system. Reaction of dichlorides 1 with trifluoroacetyl derivative 16 afforded benzo[4,5]imidazo[1,2-c]pyrimidines 19 and 20. An N-acyl and some N-alkyl derivatives of benzimidazo-thiadiazines 6 were prepared to demonstrate the potential of this new ring system as a novel scaffold for synthetic and medicinal chemistry applications. Treatment of the 4-cyano-5-methyl-benzimidazo-thiadiazine 26c with LiAlH4 resulted in an unexpected and remarkable conversion of the nitrile to give the 4,5-dimethyl-benzimidazo-thiadiazine 29.

N,N-Dialkyl-N′-Chlorosulfonyl Chloroformamidines in Heterocyclic Synthesis. III. Pyrido- and Pyridazo-Fused [1,2,4,6]Thiatriazine Dioxides

2007 ◽  
Vol 60 (2) ◽  
pp. 105 ◽  
Author(s):  
Teresa Cablewski ◽  
Erin J. Carter ◽  
Craig L. Francis ◽  
Andris J. Liepa ◽  
Michael V. Perkins
Keyword(s):  
Heterocyclic Synthesis ◽  
Ring Systems ◽  
Derivatives Of

N,N-Dialkyl-N′-chlorosulfonylchloroformamidines 1 reacted with 2-aminopyridines 2 to give novel pyrido[1,2-b][1,2,4,6]thiatriazine dioxides 3 and pyrido[2,1-c][1,2,4,6]thiatriazine dioxides 4. Reaction of 1 with 3-aminopyridazines 5 afforded pyridazo[3,2-c][1,2,4,6]thiatriazine dioxides 6 and a pyridazo[2,3-b][1,2,4,6]thiatriazine dioxide 7. The compounds 6 and 7 are derivatives of new ring systems.

N,N-Dialkyl-N′-Chlorosulfonyl Chloroformamidines in Heterocyclic Synthesis. IV. 3-Dialkylamino-1,1,8-trioxo-1H-1λ6-pyrano[3,4-e][1,4,3]oxathiazines

2007 ◽  
Vol 60 (2) ◽  
pp. 113 ◽  
Author(s):  
Teresa Cablewski ◽  
Craig L. Francis ◽  
Andris J. Liepa
Keyword(s):  
Heterocyclic Synthesis ◽  
Ring Systems ◽  
Derivatives Of

N,N-dialkyl-N′-chlorosulfonylchloroformamidines 1 reacted regioselectively with 4-hydroxy-2-pyrone derivatives 2 to give 3-dialkylamino-1,1,8-trioxo-1H-1λ6-pyrano[3,4-e][1,4,3]oxathiazines 3. Dichloride 1b reacted regioselectively with 1,3-dimethylbarbituric acid 10 to give 3-diethylamino-5,7-dimethyl-1,1,6,8-tetraoxo-1H-1λ6-pyrimido[5,4-e][1,4,3]oxathiazine 11. The compounds 3 and 11 are derivatives of new ring systems.

N,N-Dialkyl-N´-Chlorosulfonylchloroformamidines in Heterocyclic Synthesis. II. Thiazolo-, Thiadiazolo-, and Oxadiazolo-Fused [1,2,4,6]Thiatriazine Dioxides

2005 ◽  
Vol 58 (12) ◽  
pp. 891 ◽  
Author(s):  
Gary D. Fallon ◽  
Craig L. Francis ◽  
Katarina Johansson ◽  
Andris J. Liepa ◽  
Ruth C. J. Woodgate
Keyword(s):  
Heterocyclic Synthesis ◽  
Ring Systems ◽  
Derivatives Of

N,N-dialkyl-N′-chlorosulfonylchloroformamidines 1 were treated with 2-aminothiazoline, 2-aminothiazoles, 2-aminobenzothiazoles, 2-amino-1,3,4-thiadiazoles, and 2-amino-1,3,4-oxadiazoles to give a 6,7-dihydrothiazolo[3,2-b][1,2,4,6]thiatriazine dioxide 3, a 6,7-dihydrothiazolo[2,3-c][1,2,4,6]thiatriazine dioxide 4, thiazolo[3,2-b][1,2,4,6]thiatriazine dioxides 5, [1,2,4,6]thiatriazino[3,2-b]benzothiazole dioxides 7, a [1,2,4,6]thiatriazino[3,4-b]benzothiazole dioxide 8, [1,3,4]thiadiazolo[2,3-c][1,2,4,6]thiatriazine dioxides 10, [1,3,4]thiadiazolo[3,2-b][1,2,4,6]thiatriazine dioxides 11, [1,3,4]oxadiazolo[2,3-c][1,2,4,6]thiatriazine dioxides 13, and [1,3,4]thiadiazolo[3,2-b][1,2,4,6]thiatriazine dioxides 14. Compounds 3, 4, 5, 7, 8, 10, 11, 13, and 14 are derivatives of new ring systems.

scholarly journals Synthesis of 2H-furo[2,3-c]pyrazole ring systems through silver(I) ion-mediated ring-closure reaction

2019 ◽  
Vol 15 ◽  
pp. 679-684 ◽  
Author(s):  
Vaida Milišiūnaitė ◽  
Rūta Paulavičiūtė ◽  
Eglė Arbačiauskienė ◽  
Vytas Martynaitis ◽  
Wolfgang Holzer ◽  
...  
Keyword(s):  
Pyrazole Ring ◽  
Ring System ◽  
Ring Closure ◽  
X Ray Diffraction ◽  
Efficient Procedure ◽  
Ring Systems ◽  
X Ray ◽  
Catalyzed Reactions ◽  
Metal Catalyzed ◽  
Derivatives Of

Fused pyrazole ring systems are common structural motifs of numerous pharmaceutically important compounds. Nevertheless, access to derivatives of the aromatic 2H-furo[2,3-c]pyrazole ring system is still quite limited, and their chemistry and functional properties remain largely underexplored. The current study investigates routes to construct this system from easily accessible starting materials using metal-catalyzed reactions. A simple and efficient procedure to access the 2H-furo[2,3-c]pyrazole ring system was developed by employing the silver(I) ion-mediated ring-closure reaction of 4-alkynyl-3-hydroxy-1-phenyl-1H-pyrazoles as a key step. The required intermediate hydroxyalkynyl substrates for this reaction were prepared by a Pd-catalyzed coupling of 4-iodo-1-phenyl-1H-pyrazol-3-ol with ethyne derivatives. The structures of the obtained target compounds were unequivocally confirmed by detailed 1H, 13C and 15N NMR spectroscopic experiments, HRMS and a single-crystal X-ray diffraction analyses. This silver(I)-mediated 5-endo-dig cyclization of readily available 4-alkynyl-3-hydroxy-1H-pyrazoles can be used as an efficient method to access many novel 2,5-disubstituted 2H-furo[2,3-c]pyrazoles.

N,N-Dialkyl-N′-Chlorosulfonyl Chloroformamidines in Heterocyclic Synthesis. Part VII 4-Dialkylamino[1,2,3,5]Benzoxathiadiazepine Dioxides and 4-Dialkylamino-[2,1,3,5]Benzothiatriazepine Dioxides

2008 ◽  
Vol 61 (10) ◽  
pp. 785 ◽  
Author(s):  
Teresa Cablewski ◽  
Craig M. Forsyth ◽  
Craig L. Francis ◽  
Andris J. Liepa ◽  
Victor Tran
Keyword(s):  
Medicinal Chemistry ◽  
Ring System ◽  
Heterocyclic Synthesis ◽  
Derivatives Of ◽  
Acyl Derivatives

N,N-dialkyl-N′-chlorosulfonyl chloroformamidines 1 reacted with 2-aminophenols 2 to give 4-dialkylamino[1,2,3,5]benzoxathiadiazepine dioxides 3, which are examples of a new ring system. Reaction of 1 with 1,2-diaminobenzenes 7 afforded 4-dialkylamino[2,1,3,5]benzothiatriazepine dioxides 8 and 9, which are new derivatives of a rare ring system. Some N-alkyl and N-acyl derivatives of 3 and 8 were prepared to demonstrate the potential of these compounds as novel scaffolds for synthetic and medicinal chemistry.

The Meisenheimer rearrangement in heterocyclic synthesis. III. Derivatives of the 1H-[1,2]oxazepino[6,5-b]indole, thieno[2,3-e][1,2]oxazepine and [l]benzothieno[3,2-e][1,2]oxazepine ring systems

1980 ◽  
Vol 33 (6) ◽  
pp. 1335 ◽  
Author(s):  
JB Bremner ◽  
EJ Browne ◽  
PE Davies
Keyword(s):  
Acetic Acid ◽  
Tertiary Amine ◽  
Good Yield ◽  
Heterocyclic Synthesis ◽  
Ring Systems ◽  
Heterocyclic Derivatives ◽  
Derivatives Of

The new heterocyclic derivatives 3-methyl-1-phenyl-3,4,5,10-tetrahydro- 1H-[1,2]oxazepino[6,5-b]-indole (5c), 6-methyl-4-phenyl-4,6,7,8- tetrahydrothieno[2,3-e][1,2]oxazepine (6f), and 3-methyl-1-phenyl- 1,3,4,5-tetrahydro[1]benzothieno[3,2-e][1,2]oxazepine (7c) were prepared in good yield by thermal Meisenheimer rearrangement of the corresponding tertiary amine N-oxide precursors. No such rearrangement occurred on heating the N-oxides of the fused bicyclic systems 2,3,11,12-tetramethoxy-5,8,9,13b-tetrahydro-6H-dibenzo[a,h]quinolizine (3) and 8,9-dimethoxy-1,2,3,5,6,10b-hexahydropyrrolo[2,1-a]isoquinoline (4). The reduction of (5c), (6f) and (7c) with zinc in acetic acid is also described.

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