Category: indole-building-block

Colucci, Marie A. published the artcileSynthesis and Evaluation of 3-Aryloxymethyl-1,2-dimethylindole-4,7-diones as Mechanism-Based Inhibitors of NAD(P)H:Quinone Oxidoreductase 1 (NQO1) Activity, HPLC of Formula: 192820-78-3, the publication is Journal of Medicinal Chemistry (2007), 50(23), 5780-5789, database is CAplus and MEDLINE.

NAD(P)H:quinone oxidoreductase 1 is a proposed target in pancreatic cancer. The synthesis of a series of indolequinones, e.g., I (H, NO₂, NH₂, CN, CF₃ or F), based on the 5- and 6-methoxy-1,2-dimethylindole-4,7-dione chromophores with a range of phenolic leaving groups at the (indol-3-yl)methyl position, is described. The ability of these indolequinones to function as mechanism-based inhibitors of purified recombinant human NQO1 was evaluated, as was their ability to inhibit both NQO1 and cell growth in human pancreatic MIA PaCa-2 tumor cells. The inhibition of rhNQO1 was related to the pK_a of the leaving group: compounds with poorer phenolic leaving groups were poor inhibitors whereas those with more acidic leaving groups were more efficient inhibitors. These inhibition data also correlated with the inhibition NQO1 in MIA PaCa-2 cells. However, the data demonstrated that NQO1 inhibition did not correlate with growth inhibitory activity, at least in the MIA PaCa-2 cell line, suggesting that targets in addition to NQO1 need to be considered to explain the potent growth inhibitory activity of this series of indolequinones in human pancreatic cancer cells.

Journal of Medicinal Chemistry published new progress about 192820-78-3. 192820-78-3 belongs to indole-building-block, auxiliary class Fused/Partially Saturated Cycles,Dihydroindoles, name is 5-Methoxy-1,2-dimethyl-3-[(4-nitrophenoxy)methyl]indole-4,7-dione, and the molecular formula is C18H16N2O6, HPLC of Formula: 192820-78-3.

Referemce:
https://www.nature.com/articles/s41429-020-0333-2,
Preparation of Indole Containing Building Blocks for the Regiospecific Construction of Indole Appended Pyrazoles and Pyrroles

Guntur, Vamsi P. published the artcileThe potential use of tyrosine kinase inhibitors in severe asthma, Application of SU6656, the publication is Current Opinion in Allergy and Clinical Immunology (2012), 12(1), 68-75, database is CAplus and MEDLINE.

Purpose of review: Severe asthma comprises heterogeneous phenotypes that share in common a poor response to traditional therapies. Recent and ongoing work with tyrosine kinase inhibitors suggests a potential beneficial role in treatment of severe asthma. Recent findings: Various receptor and nonreceptor tyrosine kinase pathways contribute to aspects of airway inflammation, airway hyperresponsiveness, and remodeling of asthma. Selective and nonselective tyrosine kinase inhibitors may be useful to block pathways that are pathol. overactive or overexpressed in severe asthma. Recent in-vivo studies have demonstrated the utility of inhibitors against specific tyrosine kinases (epidermal growth factor receptor, c-kit/platelet derived growth factor receptor, vascular endothelial growth factor receptor, spleen tyrosine kinase, and janus kinase) in altering key aspects of severe asthma. Summary: Asthma and even severe asthma does not consist of a single phenotype. Targeting key inflammatory and remodeling pathways engaged across subphenotypes with tyrosine kinase inhibitors appears to hold promise.

Current Opinion in Allergy and Clinical Immunology published new progress about 330161-87-0. 330161-87-0 belongs to indole-building-block, auxiliary class Protein Tyrosine Kinase/RTK,Src, name is SU6656, and the molecular formula is C19H21N3O3S, Application of SU6656.

Referemce:
https://www.nature.com/articles/s41429-020-0333-2,
Preparation of Indole Containing Building Blocks for the Regiospecific Construction of Indole Appended Pyrazoles and Pyrroles

Bartscht, Tobias published the artcileTGF-β Signal Transduction in Pancreatic Carcinoma Cells is Sensitive to Inhibition by the Src Tyrosine Kinase Inhibitor AZM475271, Application In Synthesis of 330161-87-0, the publication is Anti-Cancer Agents in Medicinal Chemistry (2017), 17(7), 966-972, database is CAplus and MEDLINE.

Background: Earlier results from our group have shown that in pancreatic ductal adenocarcinoma (PDAC)-derived cells transforming growth factor (TGF)-β1-dependent epithelial-mesenchymal transition (EMT) and cell motility was inhibited by the Src inhibitors PP2 and PP1 both of which targeted the TGF-β receptors for inhibition. Objective: In this study we evaluated the impact of another Src inhibitor, AZM475271, on various TGF-β responses in PDAC cells. Method: The effect of AZM475271 on TGF-β1-induced random cell migration (chemokinesis), the expression of EMT and migration/invasion-associated genes, TGF-β-induced luciferase activity, and C-terminal phosphorylation of Smad2 and Smad3 was measured in the PDAC-derived Panc-1 and Colo357 cell lines using real-time cell migration assays, quant. real-time PCR, luciferase reporter gene assays and phosphoimmunoblotting, resp. Results: AZM475271 effectively blocked TGF-β1-induced chemokinesis of Panc-1 cells in a dose-dependent fashion and inhibited the high chemokinetic activity of Panc-1 cells with ectopic expression of a constitutively active ALK5T204D mutant. AZM475271 but not another Src inhibitor, SU6656, partially relieved the suppressive effect of TGF-β1 on E-cadherin and inhibited TGF-β1-induced upregulation of the MMP2, MMP9, N-cadherin and vimentin genes, activity of a TGF-β1-dependent reporter gene, and activation of Smad2 and Smad3. Conclusion: Our data suggest that AZM475271 cross-inhibits tumor-promoting TGF-β signaling and may thus function as an inhibitor of both TGF-β and Src in both exptl. and clin. therapies against metastatic dissemination in late-stage PDAC.

Anti-Cancer Agents in Medicinal Chemistry published new progress about 330161-87-0. 330161-87-0 belongs to indole-building-block, auxiliary class Protein Tyrosine Kinase/RTK,Src, name is SU6656, and the molecular formula is C19H21N3O3S, Application In Synthesis of 330161-87-0.

Referemce:
https://www.nature.com/articles/s41429-020-0333-2,
Preparation of Indole Containing Building Blocks for the Regiospecific Construction of Indole Appended Pyrazoles and Pyrroles

Palani, Vignesh published the artcileA pyrone remodeling strategy to access diverse heterocycles: application to the synthesis of fascaplysin natural products, Name: 5-Methoxy-2-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-1H-indole, the publication is Chemical Science (2021), 12(4), 1528-1534, database is CAplus and MEDLINE.

The synthesis of diverse N-fused heterocycles, including the pyrido[1,2-a]indole scaffold, e.g., I, using an efficient pyrone remodeling strategy was described. The pyrido[1,2-a]indole core was demonstrated to be a versatile scaffold that could be site-selectively functionalized. The utility of this novel annulation strategy was showcased in a concise formal synthesis of three fascaplysin congeners.

Chemical Science published new progress about 683229-62-1. 683229-62-1 belongs to indole-building-block, auxiliary class Indole,Boronic acid and ester,Ether,Boronate Esters,Boronic Acids,Boronic acid and ester, name is 5-Methoxy-2-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-1H-indole, and the molecular formula is C15H20BNO3, Name: 5-Methoxy-2-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-1H-indole.

Referemce:
https://www.nature.com/articles/s41429-020-0333-2,
Preparation of Indole Containing Building Blocks for the Regiospecific Construction of Indole Appended Pyrazoles and Pyrroles

Blaikie, K. G. published the artcileMethoxyindoles and their derivatives, Name: Ethyl 7-methoxy-1H-indole-2-carboxylate, the publication is Journal of the Chemical Society, Transactions (1924), 296-335, database is CAplus.

2,5-O₂N(HO)C₆H₃Me, m. 128°, was obtained in 58 g. yield (together with 42 g. of 4,5-O₂N(HO)C₆H₃Me) by slowly adding 140 g. m-HOC₆H₄Me in 140 g. AcOH to a stirred mixture of 200 g. HNO₃ (d. 1.5) and 400 g. AcOH at -8° to -5°, and removing the 4-NO₂ derivative by steam distillation Me₂SO₄ (252 g.) added to 153 g. 2,5-O₂N(HO)C₆H₃Me and 46 g. Na in 750 cc. MeOH gave a 90% yield of 2,5-O₂N(MeO)C₆H₃Me (I), m. 55°. 2-Nitro-5-methoxyphenylpyruvic acid (II), yellow, m. 128° (phenylhydrazone, yellow, m. 151-2° (decomposition)), results in 51 g. yield from 50 g. of I and 63 g. (CO₂Et)₂ added to a suspn. of 35 g. EtONa in 300 cc. dry Et₂O. Oxidation of II by H₂O₂ in 2% NaOH gave 2-nitro-5- methoxyphenylacetic acid, m. 176°. Reduction of II in NH₄OH by FeSO₄ gave a 73% yield of 5-methoxyindole-2-carboxylic acid (III), m. 196-7° (evolution of gas). Warmed with Ehrlich’s reagent, a deep pink color is produced, which fades on cooling. Me ester, m. 177°. Et ester, m. 156°. 2,3-O₂N(MeO)C₆H₃Me, (CO₂Et)₂ and KOEt in Et₂O give a 75% yield of 2-nitro-3-methoxy-phenylpyruvic acid (IV), pale yellow, m. 161-2°, or yellow with 0.5 AcOH of crystallization, m. 118-45°. The EtOH solution gives a deep green color with FeCl₃, destroyed by mineral acids. Phenylhydrazone, yellow, m. 159° (decomposition). Oxidation of IV gives 2-nitro-3-methoxyphenylacetic acid, m. 137-8°, while reduction with FeSO₄ and NH₄OH gives 7-methoxyindole-2-carboxylic acid (V), m. 182° and decomposes on continued heating. Et ester, m. 114°. Me ester, m. 120°. 2-Nitro-6-methoxyphenylpyruvic acid (VI), yellow, m. 47-55°; phenylhydrazone, yellow, m. 173-4° (decomposition). Oxidation with H₂O₂ gives 2-nitro-6-methoxyphenylacetic acid, yellow, m. 172°, while reduction of VI gave 4-methoxyindole-2-carboxylic acid (VII), m. 234-5°, in 63% yield. Ehrlich’s reagent gives a purple color, which disappears on cooling. Me ester, m. 143.5°. Et ester, m. 161.5°. p-MeOC₆H₄NHNH₂ (VIII), best prepared by diazotizing p-MeOC₆H₄NH₂ and reducing with SnCl₂ in concentrated HCl, m. 65°; yield, 44%. α-Ketobutyric acid p-methoxy-phenylhydrazone (IX), yellow, m. 105°. o-Methoxyphenylhydrazone (X), pale yellow, m. 112°. The action of concentrated H₂SO₄ on IX (or the components in EtOH) gives 5-methoxyskatole-2-carboxylic acid (XI), m. 200-1° (decomposition), isolated as the Et ester, m. 151-2°; Me ester, m. 156°. In the same way X gave 7-methoxyskatole-2-carboxylic acid (XII), m. 222-3°, isolated as the Me ester, m. 144-15°, the yield of the acid being only 23%. A by-product of this reaction is Et ketobutyrate phenylhydrazone, yellow, m. 59-60°. III, changed to the acid chloride by PCl₅ in AcCl, this dissolved in CHCl₃ and treated with MeNHCH₂CH(OMe)₂, gave 5-methoxyindole-2-carboxydimethylacetalyl-methylamide, m. 159°. This is converted by warming with saturated alc. HCl at 40-50° for 15 min. into a mixt, of about equal amounts of 10-methoxy-3-keto-4-methyl-3,4-dihydro-4-carboline (XIII), m. 280°, has a distinct blue fluorescence in the solid state, gives a yellow HCl salt, which is dissociated by H₂O and gives no color with Ehrlich’s reagent or with vanillin and HCl in the cold; the alc. solution has a striking lilac fluorescence; and 10- methoxy-5-keto-4- methyl-4,5-dihydroindole-1,4-diazine (XIV), m. 243°, gives a greenish blue color with Ehrlich’s reagent, fading to a pale yellow on cooling and becoming green on boiling, and gives an intense purple color with vanillin and HCl; the EtOH solution has a very faint blue fluorescence which is not increased by adding HCl. 5-Methoxyindole-2-carboxyacetalylamide m. 151-2°, results from the chloride of III and H₂NCH₂CH(OEt)₂; Ehrlich’s reagent gives a purple solution, becoming intense blue on warming, while NaNO₂ produces a green color in the cold. Vanillin and HCl produce a deep pink which becomes intense bluish violet on the addition of NaNO₂ and warming. The action of alc. HCl gives 10-methoxy-5-keto-4,5-dihydroindole-1,4-diazine (XV), sinters 265°, m. 280°. 5-Methoxyindole-2-carboxydimethylacetalylamide, m. 154°, and with alc. HCl gives XV. 5-Methoxyindole-2-carboxyacetalylmethylamide, m. 127°, is formed from the chloride of III and MeNHCH₂CH(OEt)₂; with alc. HCl it yields about equal quantities of XIII and XIV. 7- Methoxyindole-2-carboxydimethylacetalylmethylamide, obtained only as a sirup, gives with alc. HCl a mixture of approx. 4 parts 12-methoxy-3-keto-4-methyl-3,4-dihydro-4-carboline, pale yellow, m. 250°, yielding a golden-yellow HCl salt, and 1 part 12-methoxy-5-keto-4-methyl-4,5-dihydroindole-l,4-diazine, m. 135°, which gives a blue color with vanillin and HCl and a green color with Ehrlich’s solution 4-Methoxyindole-2-carboxydimethylacetalylmethylamide, m. 112°, which, with alc. HCl, gave 9-methoxy-3-keto-4-methyl-3,4-dihydro-4-carboline, m. 250°, and yields a sparingly soluble yellow HCl salt. The mother liquors gave a green color with vanillin and HCl but the diazine was not isolated. When XII was subjected to the above reactions, a compound C₁₄H₁₃O₂N₂Cl, m. 190°, was obtained, which was unchanged by treatment with 10% MeOH-KOH for 10 min. and is probably 9-chloro-12-methoxy-5-keto-4,7-dimethyl-4,5-dihydroindol-l,4-diazine. III decomposes vigorously when heated to 205-210°, yielding 5-methoxyindole (XVI), b₁₇ 176-8° m. 55°, acquires a pink tint which slowly darkens on standing, is only slightly volatile with steam (1 g. per l. of H₂O), colors a pine shaving moistened with HCl reddish violet, gives a purple precipitate with concentrated HNO₃ and NaNO₂. Picrate, bright red, m. 145°. 1-Ac derivative (XVII), b₂₅ 210-1°, m. 80-1°. Nitration of the Ac derivative gave a mixture of an a-NO₂ derivative, light brown, m. 149°, soluble in EtOH, and the b-NO₂ derivative, brown, m. 213-4°, the a-derivative predominating. Hydrolysis gave a- and b-nitro-5-methoxyindoles, yellow, m. 144° (mixture m. about 112°); the a-form gives an orange-purple color with a pine stick, the b-form a deep purple. The a-form gives a pale red color with Ehrlich’s reagent, not affected by addition of NaNO₂, while the b-form develops a red color only after addition of NaNO₂. XVI, treated with CHCl₃ and EtOH-KOH, yields a mixture of 5-methoxyindole-3-aldehyde, m. 178°, and 3-chloro-6-methoxyquinoline, m. 73-4°, separated by steam distillation XVI was also synthesized as follows: 4-Methoxy-2-aldehydophenylglycineamide oxime, yellow, m. 196° (decomposition) was obtained in 70% yield from 5,2-MeO(H₂N)C₆H₃CH:NOH and ClCH₂CONH₂ (formyl derivative, bright yellow, m. 223°); on hydrolysis yields 4-methoxy-2-aldehydophenylglycine oxime, pale yellow, m. 178°; with saturated H₂SO₃ this is changed to 4-methoxy-2-aldehydophenylglycine, bright orange, m. 183° (decomposition) (phenylhydrazone, yellow, m. 175-6°) which yields XVII on boiling with AC₂O and AcONa. V, decomposed at 230-3°, gives 73% of 7-methoxyindole, b₁₇ 157°, b₂₁ 159-61°, slowly turns brown on keeping, fairly volatile with steam (2 g. per 500 cc. H₂O), gives a deep mauve pine-shaving reaction, gives a yellow color with Ehrlich’s reagent, deepening to orange-red on warming and to a deep reddish purple on addition of dilute NaNO₂. Picrate, red, m. 156°. With alc. KOH and CHCl₃ this yields 7-methoxyindole-3-aldehyde, m. 159-60°, and 3-chloro-8-methoxyquinoline, m. 84.5°; the yield of both products was small. VII, at 245-50°, gives 4-methoxyindole, m. 69.5°, (picrate, red, m. 159-60°) gives a deep purple pine-shaving reaction and a reddish purple color with Ehrlich’s reagent. XI decomposes at 210° and gives 75% of 5-methoxyskatole, m. 66°, apparently non-volatile with steam, gives a red pine-shaving reaction and a reddish purple color with Ehrlich’s reagent. Picrate, dark red, m. 151-2°. XII similarly yields 7-methoxyskatole, b₂₀ 170° (picrate, brownish red, m. 156°). The pine-shaving reaction is a deep purplish red; Ehrlich’s reagent gives no color in the cold; on warming a reddish purple color develops. The K derivative of II gives with Me₂SO₄ 2-nitro-α-methoxycinnamic acid (XVIII), pale yellow, m. 164-5°. Na salt, yellow. Me ester, pale yellow, m. 67°; the Et ester appears to be an oil. Oxidation of XVIII gives o-O₂NC₆H₄CHO. Reduction of XVIII with FeSO₄ and NH₄OH gives the 2-amino derivative, pale yellow, crystallines with 2AcOH and m. 167°. Me ester, yellow, m. 60-1°. The acid readily loses MeOH, forming indole-2-carboxylic acid, m. 203-4° (heating above its m. p., solution in cold concentrated H₂SO₄ at room temperature for 16 hrs., boiling with 10% HCl or reduction of XVIII with FeSO₄ and NH₄OH and boiling the reaction product for 24 hrs.). 2-Nitro-α,3-dimethoxycinnamic acid, from IV, as above, m. 202° (decomposition), and reduced to the 2-amino derivative, m. 139°, and decomposing above its m. p. to give V.

Journal of the Chemical Society, Transactions published new progress about 20538-12-9. 20538-12-9 belongs to indole-building-block, auxiliary class Indole,Ester,Ether, name is Ethyl 7-methoxy-1H-indole-2-carboxylate, and the molecular formula is C12H13NO3, Name: Ethyl 7-methoxy-1H-indole-2-carboxylate.

Referemce:
https://www.nature.com/articles/s41429-020-0333-2,
Preparation of Indole Containing Building Blocks for the Regiospecific Construction of Indole Appended Pyrazoles and Pyrroles

Kudo, Noriaki published the artcileA versatile method for Suzuki cross-coupling reactions of nitrogen heterocycles, COA of Formula: C15H14BNO4S, the publication is Angewandte Chemie, International Edition (2006), 45(8), 1282-1284, database is CAplus and MEDLINE.

A wide-ranging study of Suzuki reactions which use nitrogen-containing heterocycles was described. This method was highly versatile (a single procedure was used for all substrates, including boronate esters and trifluoroborates), compatible with a variety of unprotected functionalities (e.g., NH₂– and OH-substituted substrates), and efficient even with inactivated aryl chlorides.

Angewandte Chemie, International Edition published new progress about 149108-61-2. 149108-61-2 belongs to indole-building-block, auxiliary class Indole,Boronic acid and ester,Sulfamide,Benzene,Boronic Acids,Boronic Acids,Boronic acid and ester,, name is (1-tosyl-1H-Indol-3-yl)boronic acid, and the molecular formula is C15H14BNO4S, COA of Formula: C15H14BNO4S.

Referemce:
https://www.nature.com/articles/s41429-020-0333-2,
Preparation of Indole Containing Building Blocks for the Regiospecific Construction of Indole Appended Pyrazoles and Pyrroles

Yates, C. G. published the artcileNew intermediates and dyes. X. Preparation and reactions of 2-n-alkylquinizarins, SDS of cas: 2642-37-7, the publication is Journal of the Chemical Society (1965), 626-9, database is CAplus.

2-Methylquinizarin was prepared by hydrolysis of 4-chloro-l-hydroxy-2 methylanthraquinone, or better, from 1,4-diamino-2-methylanthraquinone and aqueous alk. dithionite. 2-Propyl-, 2-butyl-, 2- hexyl-, 2-heptyl-, and 2-octylquinizarin were derived by the interaction of leucoquinizarin and an aliphatic aldehyde: this reaction appeared to be limited, as the use of decyl- and dodecylaldehyde gave quinizarin only. Inhibiting effects of the 2-n-alkyl groups in reactions with amines were examined Thus, 2-methyl-, propyl-, and butylquinizarin and aqueous NH₃ gave some disubstitution of the hydroxy groups, but with derivatives of longer alkyl chain, only monosubstitution occurred; MeNH₂ afforded yellow fluorescent products, probably formed by loss of water from 2-alkyl-1,4-bis(methylamino)anthraquinones. Whereas cyclohexylamine gave excellent yields of 2-alkyl-1,4-bis(cyclohexylamino)anthraquinones, disubstitution was inhibited in reactions with PhNH₂, which gave monoanilino derivatives

Journal of the Chemical Society published new progress about 2642-37-7. 2642-37-7 belongs to indole-building-block, auxiliary class Indole,Salt,Sulfonate,Inhibitor,Inhibitor, name is Potassium 1H-indol-3-yl sulfate, and the molecular formula is C9H9ClN2, SDS of cas: 2642-37-7.

Referemce:
https://www.nature.com/articles/s41429-020-0333-2,
Preparation of Indole Containing Building Blocks for the Regiospecific Construction of Indole Appended Pyrazoles and Pyrroles

Londregan, Allyn T. published the artcileSynthesis of Pyridazine-Based α-Helix Mimetics, Recommanded Product: 6-(4,4,5,5-Tetramethyl-1,3,2-dioxaborolan-2-yl)-1H-indole, the publication is ACS Combinatorial Science (2016), 18(10), 651-654, database is CAplus and MEDLINE.

A versatile synthesis of pyridazine-based small mol. α-helix mimetics is presented. Modular C-C, C-N, and C-O bond-forming reactions allow for the inclusion of a variety of aliphatic, basic, aromatic, and heteroaromatic side chain moieties. This robust synthesis is suitable for the preparation of small pyridazine-based libraries.

ACS Combinatorial Science published new progress about 642494-36-8. 642494-36-8 belongs to indole-building-block, auxiliary class Indole,Boronic acid and ester,Indole,Boronate Esters,Boronic acid and ester, name is 6-(4,4,5,5-Tetramethyl-1,3,2-dioxaborolan-2-yl)-1H-indole, and the molecular formula is C14H18BNO2, Recommanded Product: 6-(4,4,5,5-Tetramethyl-1,3,2-dioxaborolan-2-yl)-1H-indole.

Referemce:
https://www.nature.com/articles/s41429-020-0333-2,
Preparation of Indole Containing Building Blocks for the Regiospecific Construction of Indole Appended Pyrazoles and Pyrroles

Nakamura, Hiroshi published the artcileSensitive and specific detection of tryptophan, tryptamine and N-terminal tryptophan peptides on thin-layer plates using a unique fluorogenic reaction with fluorescamine, Recommanded Product: Potassium 1H-indol-3-yl sulfate, the publication is Journal of Chromatography (1978), 152(1), 153-65, database is CAplus.

Two sensitive and sp. methods were developed for the detection of tryptophan, tryptamine, N-terminal tryptophan peptides and other 3-(2-aminoethyl)-indoles on thin-layer plates in which the reaction is based on the unique fluorescence of the fluorescamine derivatives after treatment with HClO₄. The 1st method the compounds are separated on plates and reacted by dipping in acetone-n-hexane (1:4) containing fluorescamine, whereas in the 2nd method the compounds are first derivatized with fluorescamine at the origin of the plates by dipping in the solution and then separated When sprayed with 40% HClO₄, the fluorescamine derivatives appear as yellow-orange fluorescent spots. Certain 3,4-dihydroxyphenylethylamines and 3-methoxy-4-hydroxyphenylethylamines that have a free amino group in the side-chain also react, but they give a bluish fluorescence. Depending on the compounds, amounts of 1-800 pmole could be detected.

Journal of Chromatography published new progress about 2642-37-7. 2642-37-7 belongs to indole-building-block, auxiliary class Indole,Salt,Sulfonate,Inhibitor,Inhibitor, name is Potassium 1H-indol-3-yl sulfate, and the molecular formula is C8H6KNO4S, Recommanded Product: Potassium 1H-indol-3-yl sulfate.

Referemce:
https://www.nature.com/articles/s41429-020-0333-2,
Preparation of Indole Containing Building Blocks for the Regiospecific Construction of Indole Appended Pyrazoles and Pyrroles

Nakamura, Hiroshi published the artcilePerchloric acid, a fluorogenic spray reagent for tryptophan, tryptamine, peptides containing tryptophan and other 3-substituted indoles, Application In Synthesis of 2642-37-7, the publication is Journal of Chromatography (1978), 152(1), 167-74, database is CAplus.

When silica gel plates containing 3-substituted indoles (e.g., 3-methylindole, indole-3-acetic acid), tryptophan derivatives, tryptamine, and tryptophan-containing peptides (e.g., H-Trp-Gly-OH, H-Pro-Trp-OH, H-Lys-Trp-Lys-OH) were sprayed with 70% HClO₄, a strong yellow-orange fluorescence developed. Other indole derivatives did not give this fluorescence when sprayed with 70% HClO₄. 3-Substituted indoles can be detected at 40-850 pmole by this method.

Journal of Chromatography published new progress about 2642-37-7. 2642-37-7 belongs to indole-building-block, auxiliary class Indole,Salt,Sulfonate,Inhibitor,Inhibitor, name is Potassium 1H-indol-3-yl sulfate, and the molecular formula is C8H6KNO4S, Application In Synthesis of 2642-37-7.

Referemce:
https://www.nature.com/articles/s41429-020-0333-2,
Preparation of Indole Containing Building Blocks for the Regiospecific Construction of Indole Appended Pyrazoles and Pyrroles