Indole-3-acetyl chloride

Esterification. Indole-3-acetyl chloride (1) is converted into t-butyl indole-3-... 

Bruce and Sutcliffe obtained l-acetyl-2-methyl-3-phenylindole (123) by the action of acetyl chloride on 2-methyl-3-pheiiylindole magnesium iodide in ether.These authors were able to obtain l-benzoyl-2-benzyl-3-phenylindole (124) but not l-acetyl-2-benzyl-3-phenylindole (125) from 2-benzyl-3-phenylindole magnesium iodide by analogous procedures.3-Acetyl-2-phenylindole (126) and 3-propionyl-2-pheny]indole (127) have recently been prepared in fair yield by the acylation of 2-phenylindole magnesium iodide with acetyl and propionyl chloride, respectively. Le ete obtained a mixture of l-acetyl-3-ethylindole (128) and 2-acetyl-3-ethylindole (129) by the interaction of acetyl chloride with 3-ethylindole magnesium iodide in ether. 

Acetylchloride is a trapping agent that allows the reaction to go completion, transforming the product into a less oxidizable compound.The results of other reactions between indole (57) and substituted cyclohexa-1,3-dienes show that the photo-induced Diels-Alder reaction is almost completely regioselective. In the absence of 59 the cycloaddition did not occur the presence of [2+2] adducts was never detected. Experimental data support the mechanism illustrated in Scheme 4.14. The intermediate 57a, originated from bond formation between the indole cation radical and 58, undergoes a back-electron transfer to form the adduct 60 trapped by acetyl chloride. 

Finally, bisindolylethylenes have also been reacted with tetrahaloph-thalic anhydrides to yield color formers showing absorption in the near infrared.99 The chief advantage over the diarylethylenes is the availability of the starting materials. The bisindolylethylenes may be prepared in situ by reaction of an indole with acetyl chloride and then converted directly to the phthalide without isolation. 

Acetylindole. (Bulletin of the Chemical Society of Japan.) Put 2 g of indole in 50 ml of nitrobenzene and add 4 g of AICI3 in 50 ml of nitrobenzene. Add 1.25 g of acetyl-chloride and heat for 3 hours at 50°. Evaporate in vacuo and recrystallize the residue in ethyl aeetate to get the acetylated indole. 

A Indole, when treated with one equivalent of sodaniide and then with benzenesulfonyl chloride, gives l- pheny sutronyl)indole. The A -sulfonyl substituent activates the H-2 to deprotonation by butyl-lithium and stabilizes the lithium derivative by chelation. This oriho lithiation process facilitates subsequent acetylation at this site by acetyl chloride, affording 2-acetyl-l-(phenylsulfonyl)indole (Scheme 7,11). 

A solution of (R)-5-trans-(2-phenylsulfonylethenyl)-3-(N-methylpyrrolidin-2-ylmethyl)-lH-indole and 10% Pd/C in ethanolic hydrogen chloride (prepared from absolute ethanol and acetyl chloride and N,N-dimethylformamide was shaken under a hydrogen atmosphere at room temperature). The resultant reaction mixture was filtered through diatomaceous earth (Celite trademark), washed with absolute ethanol, and the combined filtrates were evaporated under reduced pressure. The residue was partitioned between ethyl acetate and water. The organic phase was separated, washed with water, brine, dried... 

The title compound, mapindolol 198, a potent /7-adrenoceptor blocking (antihypertensive) agent, has been synthesized200 by the Madelungs method of indole synthesis using [l-14C]acetyl chloride as starting material (equation 80). 

On treatment of 11 with palladium, an interesting disproportionation reaction takes place which yields the colorless indole derivative 14 (27,28). Reaction of betanidin with acetyl chloride in trifluoroacetic acid afforded di-C>-acetyl-betanidin (13), which could be hydrolyzed back to 1 with concentrated hydrochloric acid (5). This demonstrated the presence of two phenolic hydroxyl groups in betanidin, and from consideration of the H-NMR data formula 1 was assigned to betanidin. 

Ziegler and co-workers (216, 217) have described a new approach to the quebrachamine skeleton involving internal cyclization of an acetic acid side chain to a 2-unsubstituted indole. The key intermediate is the disubstituted piperidine 466, which is treated with indolyl-3-acetyl chloride in aqueous sodium carbonate-methylene chloride to afford a lactam ester, 467. 

Wiest and co-workers have demonstrated that indole will participate in electron-transfer sensitized Diels-Alder reactions [14c, 41]. Irradiation of the electron-transfer sensitizer triphenylpyrylium tetrafluoroborate 21 in a methylene chloride solution containing indole, 1,3-cyclohexadiene and acetyl chloride yields the adduct 22 as an exo and endo mixture in a 1 3.3 ratio and a combined yield of 70% (Scheme 9) [14c,41a], Experiments are reported [14c, 41a] which demonstrate that the reaction proceeds by electron transfer from the indole to the excited sensitizer the indole radical cation produced then attacks the diene to give an intermediate 23 (Ri = = H) which, in conjunction with back-electron transfer from the... 

The indole ring can act as a dienophile under the conditions of electron-transfer catalysis. In this mechanism, the indole radical cation is generated as a transient intermediate by single electron oxidation. Indole (58) and cyclohexadiene (59) react to give (60) in the presence of triarylpyrylium salts which act as photosensitizers. The reaction is carried out in the presence of acetyl chloride which traps and stabilizes the adduct (Equation (139)) <90SL275,91JOC1405>. 

As Table 8 illustrates, the venerable Japp-Klingemann variation of the Fischer indolization continues to attract interest. Entry 1 features a three-component Japp-Klingemann indolization involving diazonium salts, acid chlorides, and amines or alcohols and involving the intermediacy of a-hydrazono carboxylic acid esters and amides prior to indole ring formation [385]. Entry 2 describes a preparation of 5-indolyl-Mannich bases and, hence, an expedient source of 5-(chloromethyl)indoles (acetyl... 

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