First synthesis of 5,6-dihydro-4H-furo[3,2-f]pyrrolo- [1,2-a][1,4]diazepines

The synthetic pathway leading to 5,6-dihydro-4H-furo[3,2-f]pyrrolo[1,2-a][1,4]diazepines is described in four steps starting from α-bromophenones via 2-amino-3-furonitriles.     

A novel practical synthesis of pyrrolo[1,2-a]thieno[2,3-e][1,4]diazepines

In an investigation of new heterocyclic systems, a novel way to obtain pyrrolo[1,2-a]thieno[2,3-e][1,4]diazepine 8 was effected by ring closure to the appropriate nitroaldehyde compound which was synthesized in five steps from 3-bromomethyl-2-nitrothiophene 1 .     

Synthesis of 5,6-dihydro-4H-pyrrolo[1,2-a]thieno[2,3-f][1,4]diazepines

The reduction of 1-[3-(thienyl-2-carbonitrile)]pyrrole, formed by condensation of 3-aminothiophene-2-carbonitrile with 2,5-dimethoxytetrahydrofuran, gave 1-[3-(thienyl-2-aminomethyl)]pyrrole. This compound was found to be a convenient intermediate for the preparation of 4-aryl-5,6-dihydro-4H-pyrrolo[1,2-a]thieno-[2,3-f][1,4]diazepines which was accomplished by two different synthetic routes.     

Pyirolothieno[1,4]diazepines. Part IV. First synthesis of pyrrolo-[1,2-a]thieno[2,3-f][1,4]diazepine Derivatives

Treatment of 3-(2-formyl-1H-pyrrol-1-yl)-2-thiophenecarboxamide by various nucleophiles like methyl ketones, amines, alcohols, thiols or acetates led to new 5,6-dihydro-4H-pyrrolo[1,2-a]thieno-[2,3-f][1,4]diazepines.     

Diazepines. III. Synthesis of 4H-Pyrrolo[1,2-a] thieno[3,2-f] [1,4] diazepines

The synthesis of 4H-pyrrolo[1,2-a]thieno[3,2-f] [1,4]diazepines ( 8 ) is described. Phthal-imidomethylfurans 1 were treated with bromine-methanol to give the dihydrofurans 2 , which were hydrolyzed and then liydrogenated over Raney nickel or with zinc-acetic acid to afford the 1,4-diketones 5 . Condensation of 2-amino-3-benzoylthiophenes 6 with 5 gave 3-benzoyl-2-pyrrolylthiopenes 7 . The removal of the phthaloyl group from 7 with hydrazine hydrate and ring closure to the diazepine ring yielded the new heterocycles 8 .     

New access to 4-phenyl-6H-pyrrolo[1,2-a]thieno[3,2-f]-[1,4]diazepines

Pyrrolo[1,2-a]thieno[3,2-f][1,4]diazepines were obtained in an original one step synthesis by treatment of imines 1 with paraformaldehyde in refluxing ethanol. The intermediate Mannich bases were also converted into the thienooxadiazocines 12 and the diazepine N-oxide 13 .     

Synthesis of novel imidazo[1,2-a]pyrrolo[2,1-c][1,4]benzodiazepines and pyrimido[1,2-a]pyrrolo[2,1-c][1,4]benzodiazepines

Several 1 1-amino-5H-pyrrolo[2,1-c][1,4]benzodiazepines have been used as starting material to prepare a number of derivatives of 9H-imidazo[1,2-a]pyrrolo[2,1-c][1,4]benzodiazepines and 10H-pyrimido[1,2-a]pyrrolo[2,1-c][1,4]benzodiazepines. The imidazole nucleus was built by reaction of amidines with ethyl bromopyruvate or aminoacetaldehyde dimethylacetal. Several derivatives of imidazo[1,2-a]pyrrolo[2,1-c][1,4]benzodiazepine have been prepared by formylation of the pyrrole ring followed by formation of thioamides. Condensation of 11-amino-5H-pyrrolo[2,1-c][1,4]benzodiazepines with diethyl ethoxymethylenemalonate afforded intermediate diesters which were transformed into the corresponding 10H-pyrimido[1,2-a]pyrrolo[2,1-c]-benzodiazepines.     

Pyrrolothieno[1,4]diazepines. Part V. Study of their chemical reactivity and first synthesis of oxazino[4,3-c]pyrrolo[1,2-a]thieno[2,3-f] [1,4]diazepines

The study of the chemical reactivity of methyloxopyrrolothienodiazepinones led to new derivatives such as oximes, methyloximes, hydrazones and alcohols and also, according to an intramolecular cyclization, to new oxazino[4,3-c]pyrrolo[1,2-a]thieno[3,2-f][1,4]diazepines.     

Synthesis of Benzofuro[3,2-e][1,4]diazepines

A synthesis of 4-N-oxides and of 3-hydroxy derivatives of 1,3-dihydro-2H-benzofuro[3,2-e][1,4]diazepin-2-ones and of 2,3-dihydro-1H-benzofuro[3,2-e][1,4]diazepines is described. Condensation of 2-acetyl- and 2-benzoyl-3-ethoxycarbonylaminobenzofurans with acrylonitrile gave derivatives of 1,2-dihydro- and of 1,2,3,4-tetrahydrobenzofuro[3,2-b]pyridine.     

Synthesis of 5H-imidazo[2,1-c]pyrrolo[1,2-a][1,4]benzodiazepine

We have synthesized 5H-imidazo[2,1-c]pyrrolo[1,2-a][1,4]benzodiazepine 1 in five steps from 1-(2-amino-methylphenyl) pyrrole 4 . Amidino derivatives 11-12 have also been prepared.     

A facile synthesis of pyrrolo[1,2-a]pyrimidines and pyrrolo[1,2-a]imidazoles

The one-step synthesis of 8-t-butoxycarbonyl-6,7-dimethyl-2-oxo-1,2,3,4-tetrahydropyrrolo[1,2-a]pyrimidine from acetyl methyl carbinol, 3-aminopropionic acid, and t-butyl cyanoacetate is reported. Utilizing a similar technology under basic conditions, 7-substituted 5,6-dimethyl-2-oxo-2,3-dihydro-(1H)-pyrrolo[1,2-a]imidazole is synthesized from acetyl methyl carbinol, ethyl glycinate, and the appropriate acetonitrile.     

Electronic spectra of pyrrolo[2,1-a]isoquinolines and pyrrolo[1,2-f]phenanthridines

The electronic absorption spectra of dioxo-compounds of the pyrroto[2,1-a]isoquinoline and pyrrolo[1,2-f]phenanthridine series and products of their condensation with o phenylenediamine were studied. The influence of substituents was demonstrated; halochromic phenomena in sulfuric acid medium were described; the fluorescence spectra are discussed.Institute of Technical Chemistry, Urals Branch of the Russian Academy of Sciences, Perm' 614600. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 5, pp. 650-653, May, 1995. Original article submitted March 14, 1995.     

Cyclisations intramoléculaires: Accés aux 9-oxo-4H,9H-pyrrolo[1,2-a]thieno[2,3-d]pyridine et 4-oxo-4H,9H-pyrrolo[1,2-a]thieno[2,3-d]pyridine. Synthèse des pyrrolo[1,2-a]thieno[3,2-e][1,4]diazepine et pyrrolo[1,2-a]thieno[2,3-e][1,4]diazepine

Synthesis of 1-(2- or 3-thienylmethyl)methyl)pyrrole and some derivatives are described from halogenomethylthiophenes. The intramolecular cyclisation of carboxylic acid 19 and 20 leads to pyrrolothienopyridines 22 and 23. On the other hand azide-aldehydes 29 and 30 in aqueous acid mixture gave the pyrrolo[1,2a]thieno[2,3-e][1,4]diazepine.     

Concise diastereospecific pyrrolo[1,2-a][1,4]benzodiazepinone synthesis

A concise synthesis of the novel pyrrolo[1,2-a]benzodiazepine system, by using the metallo carbenoid/spiro-[6,5]-ammonium ylide/Stevens[1,2]-shift with ring-expansion approach, was reported. The overall cascade process resulted stereospecific.     

Synthesis and reactivity of furo[2,3-e]pyrrolo[1,2-a][1,4]diazepin-9-one

A convenient method for the synthesis of furo[2,3-e]pyrrolo[1,2-a][1,4]diazepin-9-one is described. It has been C-alkylated with amine (piperidine, morpholine, 4-methylpiperazine) and N-alkylated with alkyl halides (methyl iodide and benzyl chloride).