2-Amino-3(2H)isoquinolone, 2,3-Benzodiazepin-4(5H)one, and Related Compounds

Halford, J. O.; Raiford, R; Weissmann, Bernard

doi:10.1021/jo01065a050

Cited by 17 publications

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“…NMR spectra were recorded at 295 K on a Bruker Avance III HD 600 (600 and 150 MHz for 1 H and 13 C NMR spectra, respectively) spectrometer equipped with a Prodigy cryo-probehead, or on a Bruker Avance III 400 (400 and 100 MHz for 1 H and 13 C NMR spectra, respectively) spectrometer. 1 H assignments were accomplished using general knowledge of chemical shift dispersion with the aid of the 1 H-1 H coupling pattern. CDCl 3 or DMSO-d 6 was used as the solvent and TMS as the internal standard.…”

Section: Scheme 6 Preparation Of Target Compounds 15hk Using a Modifi...mentioning

confidence: 99%

“…The synthesis of 2,3-benzodiazepine-4-ones 1 (Scheme 1) and the investigation of their pharmacological activity looks back to a long history. The first representatives were prepared by Halford et al 1 by a procedure which was studied in detail by Wermuth and Flammang. [2][3][4] According to this, treatment of o-formyl-, o-acetyl-and o-aroylphenylacetic acids 2 with hydrazine or alkylhydrazines afforded 2,3-benzodiazepine-4-ones 1, beside 2-aminoisoquinolin-3(2H)-ones 3 as by-products (Scheme 1).…”

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confidence: 99%

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Practical Synthesis of Variously Substituted 2,3,4-Benzothiadiazepine 2,2-Dioxides

et al. 2022

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The significant pharmacological activity of 2,3-benzodiazepine-4-ones led to an increased interest in this compound family. However, the literature of the closely related 2,3,4-benzothiadiazepine 2,2-dioxides is rather scarce. Earlier we elaborated a synthesis of 5-aryl congeners variously substituted at the aromatic ring. In the present study, a new synthetic route was investigated via highly versatile intermediates, to extend the reaction to a wider aromatic substitution pattern and to the preparation of 5-alkyl and 5-H derivatives. The essence of this approach is, starting from benzaldehyde acetals, acetophenone and benzophenone ketals, to synthesize ortho-formyl- and ortho-acyl-arylmethanesulfonyl chlorides, which are suitable precursors of the target compounds. The synthesis was implemented as follows: ortho-lithiation of the corresponding acetals and ketals and subsequent treatment with paraformaldehyde, or alternatively in two steps, with DMF or ethyl formate, followed by reduction with NaBH4, led to the corresponding hydroxymethyl derivatives. Reaction of these latter with methanesulfonyl chloride gave mesylates that were used to S-alkylate thiourea to afford S-alkylisothiouronium salts. The final steps of the synthesis were carried out in a telescoped reaction. Treatment of the S-alkylisothiouronium salts with N-chlorosuccinimide resulted in the corresponding arylmethanesulfonyl chlorides. Subsequent reaction with hydrazine hydrate followed by an acidic treatment gave 2,3,4-benzothiadiazepine 2,2-dioxides.

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Section: Scheme 6 Preparation Of Target Compounds 15hk Using a Modifi...mentioning

confidence: 99%

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confidence: 99%

Practical Synthesis of Variously Substituted 2,3,4-Benzothiadiazepine 2,2-Dioxides

et al. 2022

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“…83, 141 (1950). [5] A number of 2-alkoxycarbonylaziridines have been prepared by the same method: E. Kyburz, H. Els. St. Majnoni, G. Englert, C .…”

Section: -Cyanoaziridinementioning

confidence: 99%

2‐Cyanoaziridine

Burzin¹,

Enderer²

1972

Angew. Chem. Int. Ed. Engl.

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Such reasoning provides a qualitative explanation of the varying A I E values of the 1,fdithia compounds (Table 2) on the basis of Figure 2.Fig. 2. Qualitative M O schemes for ns/n, and ns:u interactions in 1,3-dithia compounds.EHT calculations on the open-chain compound 2,4dithiapentane in the C,, conformation show the n, MO to lie above the n-MO whose symmetry properties (asymmetric with regard to both mirror planes) rule out admixture of cCH, orbitals. In the 1,3-dithiane (C,) and in bis(thioph0sgene) (DZh), however, combinations with molecular orbitals 0 , are symmetry allowed for both n, and n-so that the sequence IE(n-)3.5A[91); this can be interpreted in terms of predominating "through bond" interaction['].

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“…Pyrolytic dehydration of 2-acetylphenylacetic acid phenylhydrazone was shown to give the 2,3-benzodiazepinone derivative, while warming in a 1 M solution of sulfuric acid in acetic acid results in cyclization into the 3-isoquinolone derivative [18]. In this context we studied the thermal cyclization of hydrazone 8 (Scheme 5).…”

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confidence: 99%