Indol-diazepine

Carboxy substituted diazepines 226 and 229 react with phenyl isocyanate to afford pyrimido diones 227 and 230, correspondingly (Scheme 48, Section 3.1.1.3 (1993JHC897)). N-Hydroxymethylation on an indole ring annulated to benzaze-pinone, as well as formation of the corresponding carbamate and urea, has been described (2004MI1076). 

The central pyridazine ring of the condensed indole derivative in 4.31. was built up by the electrophilic attack of the pyridylpalladium intermediate on the indole ring.38 By blocking the 2-position of indole through substitution the ring closure was directed into the peri-position forming a diazepine ring.39... 

Pyrimido(4,S-Jb [l,4]diazepin 4-one. 977 Pyrimido[l,2-6iind le. 1004 Pyrimido(l,2-aliiidole. 1329 I rimido[l,6-[Pg.778]

The naturally occurring nucleoside analogues discussed in this section contain the IV-glycosyl linkage and either purine, pyrimidine, imidazole, diazepin, or indole rings. The purine nucleosides inhibit protein synthesis, RNA and DNA synthesis, and methyltransferases they have antimycoplasmal, antiviral, hypotensive, antifungal, antimycobacterial, and antitumor activities and induce sporulation (1—4). The pyrimidine nucleosides inhibit protein synthesis, virus replication, RNA and DNA synthesis, and cAMP phosphodiesterase. The imidazole nucleosides inhibit nucleic acid synthesis. The diazepin nucleosides inhibit adenosine deaminase (ADA). The indole nucleosides inhibit bacteria, yeast, fungi, and viruses. 

The thermal and photochemical [4 + 2] cycloadditions of o-quinones with olefinic and acetylenic dienophiles have been extensively reviewed4,5,200 and include their 4tt heterodiene Diels-Alder reactions with olefins,201-204 vinyl ethers,205 enamines,206 selected dienes,207-209 dipheny-lketenimines,210 ketenes,209,210 fulvenes,211 and selected heterocycles including furan,207-209,212 benzofuran,209,212,215 indoles,213 azepines,214 and 1,2-diazepines.214 The tetrahalo-substituted o-quinones, tetrachloro- and tetrabromo-o-quinone, generally participate in heterodiene [4 + 2] cycloadditions at an increased rate over the unsubstituted systems and generally provide higher overall yields of the Diels-Alder products.4,5 With simple olefins, the dienophile geometry is maintained in the course of the thermal [4 4- 2] cycloadditions [Eq. (52)],203,204... 

New examples of well established photo-induced rearrangements arising by electrocyclic pathways have been reported. A classification for such processes in systems containing heteroatoms has been proposed. 1/f-l-Benzazepines are readily converted on irradiation in tetrahydrofuran into dihydrocyclo-but[6]indoles, whereas the 4,6a-dihydro[l,2]diazeto[l,4-a]pyrroles (18) are formed preferentially on irradiation of the 3//-l,2-diazepines (19). A high yield... 

Diazepines.—Formation. There is a report on the formation of the C=N bond in l,4-benzodiazepin-2-ones and in l,2-dihydropyrazin-2-ones by the intramolecular reaction of aldehyde groups or keto-groups with iminophos-phoranes the process had earlier been described in the patent literature. 1,4-Benzodiazepin-2-ones have also been prepared from indoles by ozonolysis followed by reductive cyclization with hydrazine hydrate. A new simple syn-... 

An analogous reaction forms the key step in a direct and versatile route to 4-substituted indoles from quinoline N-oxides. Irradiation of the latter gave (171 X = H), which was hydrolysed by chromatography on silica to give the indolinol (172) this was transformed into (173). " The benzoxazepines (171) are stable solids when X = CN, but they rearranged if irradiated (254 nm) to give the 3-formylindole (174) [cf. the analogous reactions of diazepines and oxepines described above]. 

The susceptibility of the pyrrole ring to electrophilic attack has been used in the synthesis of pyrrolo-fused 1,4-diazepines, for example, A-(3-acetylaminopropyI)-3-methyl indole underwent a Bischler-Napierelski-type cyclodehydration on treatment with phosphorous oxychloride in benzene to give ll-methyl-4,5-dihydro-3ff-l,4-diazepine[l,2-a]indole <91IJC(B)1018>. In another example the acyl azide (143) cyclized to the furo[2,3-e]pyrrolo[l,2-a]-l,4-diazepine-9-one (144) (Scheme 25) <92JHC1507>. 

A range of indolo(triazolo)-l,4-diazepine derivatives 104 were obtained by a microwave-heated three-component reaction involving tandem N-alkylation of indole 101 with epichlorohydrin 102, ring-opening of the epoxide with azide 103, and intramolecular azide-alkyne 1,3-dipolar cycloaddition reactions (13BJO401). Fused triazolodiazepinones were obtained via azide-alkyne 1,3-dipolar cycloaddition followed by lactamization (13JHC430). 

In 2008, Fujii, Ohno and their co-workers developed an interesting method for the preparation of indole-fused 1,4-diazepines by eopper-catalyzed domino three-component coupling-indole formation-lV-aiylation. ... 

In Chap. 4, the author describes a direct access to indole-fused tetracyclic compounds containing a 1,4-diazepine framework by copper-catalyzed domino three-component coupling, cyclization, and A -arylation, which involve the formation of one carbon-carbon bond and three carbon-nitrogen bonds. 

Concise Synthesis of Indole-Fused 1,4-Diazepines through Copper(I)-Catalyzed Domino Three-Component Coupling-Cyclization- -Arylation under Microwave Irradiation... 

---