118.14 | - Page 2 of 2 - Indole Building Blocks

Frydman, Benjamin et al. published their research in Journal of the American Chemical Society in 1965 | CAS: 271-29-4

1H-Pyrrolo[2,3-c]pyridine (cas: 271-29-4) belongs to indole derivatives. Indole exists overwhelmingly in the 1H-indole form as do other simple indoles.Indole was synthesized in moderate yield via an o-naphthoquinone catalyzed tandem cross-coupling of substituted aniline and benzylamine under aerobic oxidation conditions.Synthetic Route of C7H6N2

Pyrroles from azaindoles. A synthesis of porphobilinogen was written by Frydman, Benjamin;Despuy, Maria E.;Rapoport, Henry. And the article was included in Journal of the American Chemical Society in 1965.Synthetic Route of C7H6N2 This article mentions the following:

The synthesis of porphobilinogen in 19% overall yield from 2-methoxy-4-methyl-5-nitropyridine (I) is described. I, m.p. 81° λ 289 mμ (ε 6800), was prepared by treating the chloro derivative with methanolic NaOMe. I with C₂H₅OK and di-Et oxalate gave 93% yield of ethyl 2-methoxy-5-nitro-4-pyridinepyruvate (II), m.p. 97-98°, λ 287 mμ (ε 10,100), δ 7.8 (H-3), 9.1 (H-6), and 7.2 (CH:C(OH)COOR). Hydrogenation of II over Pd-C catalyst and cyclization gave 85% yield of ethyl 5-methoxy-6-azaindole-2-carboxylate (III), m.p. 103-106°, λ 278 mμ (ε 15,000), 287 (17,000), 344 (3600), δ 7.1, 7.2(H-3, H-4), and 8.7 (H-7). Hydrogenation with Pt catalyst yielded III and a substantial amount of 1,2,3,4-tetrahydro-3-hydroxy-6-methoxy-1,7-naphthyridin-2-one, m.p. 215° from C₂H₅OH, λ 248 mμ (14,070), δ (in CF₃COOH) 3.1 (H-4 × 2), 4.5 (H-3), 7.0 (H-5) and 8.5 (H-8). III with Me₂NH and paraformaldehyde yielded ethyl 3-dimethylaminomethylene-5-methoxy-6-azaindole-2-carboxylate (IV) di-HCl salt, m.p. 162° λ 283 mμ (ε 12,100), 292 (13,800), 347 (3700), δ (D₂O) 8.2 (H-7). IV with di-Et sodiomalonate gave the corresponding malonate (V) HCl, m.p. 188° λ (ε 18,600), 294 (20,400), 350 (4600). V was readily converted to 2-methoxy-3-propionic acid-6-azaindole (VI), m.p. 210-215°, λ 283 mμ (ε 13,000), 292 (15,700), 350 (4400). VI on heating at 150° with 48% HBr yielded 70% of 2-carboxy-5-oxo-5,6-dihydro-1-H-pyrrolo[2,3-c]pyridine-3-propionic acid (VII), m.p. 280° dec., λ 292 mμ (ε 4200) and 302 (4400). VII with Pd-C and H in aqueous solution at pH 7 yielded 2-carboxyporphobilinogen lactam in 90% yield, m.p. 295° λ 276 mμ (ε 12,600). In boiling water porphobilinogen lactam (VIII), m.p. 295° dec., was obtained in 80% yield. VIII with 2N KOH at 20° for 72 hrs. yielded 85% of porphobilinogen hydrate, m.p. 167°. A similar series of reactions was carried out starting with 2-benzyloxy-4-methyl-5-nitropyridine rather than I. All uv determinations are in EtOH. In the experiment, the researchers used many compounds, for example, 1H-Pyrrolo[2,3-c]pyridine (cas: 271-29-4Synthetic Route of C7H6N2).

Referemce:
Indole alkaloid derivatives as building blocks of natural products from Bacillus thuringiensis and Bacillus velezensis and their antibacterial and antifungal activity study,
Preparation of Indole Containing Building Blocks for the Regiospecific Construction of Indole Appended Pyrazoles and Pyrroles

Whelligan, Daniel K. et al. published their research in Journal of Organic Chemistry in 2010 | CAS: 271-29-4

1H-Pyrrolo[2,3-c]pyridine (cas: 271-29-4) belongs to indole derivatives. Indole is an important structural motif of various drugs, therapeutic leads besides its prevalence in numerous natural products, agrochemicals, perfumery, and dyes. It is used in perfumery and in making tryptophan, an essential amino acid, and indoleacetic acid (heteroauxin), a hormone that promotes the development of roots in plant cuttings.SDS of cas: 271-29-4

Two-Step Synthesis of Aza- and Diazaindoles from Chloroamino-N-heterocycles Using Ethoxyvinylborolane was written by Whelligan, Daniel K.;Thomson, Douglas W.;Taylor, Dawn;Hoelder, Swen. And the article was included in Journal of Organic Chemistry in 2010.SDS of cas: 271-29-4 This article mentions the following:

An efficient two-step route to a broad range of aza- and diazaindoles, e.g. I, was established, starting from chloroamino-N-heterocycles, without the need for protecting groups. The method involves an optimized Suzuki-Miyaura coupling with (2-ethoxyvinyl)borolane followed by acetic acid-catalyzed cyclization. In the experiment, the researchers used many compounds, for example, 1H-Pyrrolo[2,3-c]pyridine (cas: 271-29-4SDS of cas: 271-29-4).