Indole 3-aldehyde

Under conditions more similar to those of the Reimer-Tiemann reaction 3-bromopyridine was obtained from pyrrole and bromo-form. Treatment of pyrrole with chloroform and aqueous alkali gave pyrrole-2-aldehyde curiously, the formation of 3-chloropyridine under these conditions does not appear to have been reported, in spite of being frequently quoted. However, indole gave both indole-3-aldehyde and 3-chloroquinoline under these conditions [Eq. (10)]. 

Tryptophane (10, 100) By condensation of indole-3-aldehyde with hydantoin in the presence of piperidine, followed by treatment of the product with ammonium sulfide and ammonium hydroxide at ioo° for 500 hours, Boyd and Robson, Biochem. J. ag, 2256 (1935). 

The ability of HRP to degrade the plant hormone indole-3-acetic acid (lAA) in the absence of hydrogen peroxide was noted as early as 1955 (136). Plant peroxidases are now known to be of major importance in the metabolism of lAA (137) (note that they are often referred to as indole acetic acid oxidases in the older literature). The mechanism of lAA oxidation by HRP C is complex and has been studied experimentally in great detail by several groups (23, 137). Reaction products include indole-3-methanol, indole-3-aldehyde, and 3-methylene oxin-dole, which is probably a nonenzymatic conversion product of indole-3-methylhydroperoxide. The most important developments in this area have been reviewed (23). 

Aldehyde oxidase purified from maize coleoptiles is a multicomponent enzyme that contains a molybdenum cofactor, nonheme iron, and flavin adenine dinucleotide (FAD) as prosthetic groups.111 When substrate specificity of the aldehyde oxidase was tested, good activity was detected with IAAld, indole-3-aldehyde, and benzaldehyde among others. The addition of NADP and NADPH did not change the activity. In contrast, in maize endosperm, tryptophan-dependent IAA biosynthesis was dependent on an NADP/NADPH redox system, which may mean that the two tissues of maize are utilizing different pathways or different redox systems for IAA biosynthesis.112... 

Indole-3-aldehyde, 879 Indole-3-carbonitrile, 745-746 Indole-3-carboxaldehyde, 745-746 Indole-2-carboxylic add, 839 Indoles, 642 Indolines, 642... 

Since this process is involved in thyroxine biosynthesis,14 it is likely that the enzymic oxygenation also involves dioxetanes. The horseradish peroxidase (HRP)-catalyzed oxygenation of indole-3-acetic acid (53) affords electronically excited indole-3-aldehyde (54).83b The a-peroxylactone (2j) was postulated to be responsible for the feeble light... 

Quinazolin-2-one was obtained quantitatively by fusing 2-aminobenzaldehyde with urea (10 min at 150°C).76,91 Similarly, 2-amino-3-formylpyridine and urea (15 min at 160°C) gave an excellent yield of pyrido[2,3-d]pyrimidin-2-one (see 3).92 Finally, as an example from jt-excessive chemistry, 2-amino-indole-3-aldehyde was converted to its 2-benzyloxycarbonyl derivative, which benzylamine quantitatively converted to 3-benzyl-9f/-pyrimidino-[4,5- >]indol-2-one (87)93... 

Of the six nitrogenous metabolites E-6 to E-11 isolated by Kishi etal., E-9 is neoechinulin and E-11 is echinulin E-8 is identical with neoechinulin C (35), and E-10 is neoechinulin B (36). E-7 appears to be new, and is a tetradehydro-echinulin of structure (37). These last three metabolites were synthesised by condensation of the appropriate indole-3-aldehyde derivative with methylene-diketopiperazine (38) [cf. (34) -> (29)]. 

Internal auxins of plants, other than lAA, are also known, and include indole-3-ethanol (lEt), indole-3-aldehyde, indole-3-carboxylic acid, and indole-3-acetonitrile (IAN) [3]. 

ABSTRACT. Selective formylation of phenol at the 4-position is achieved by using 3-cyclodextrin as catalyst in the reaction of phenol with chloroform in aqueous alkali. The reactions of 1,3-dihydroxybenzene and indol, respectively, in the place of phenol give 2,4-dihydroxybenz-aldehyde and indole-3-aldehyde in virtually 100% selectivies and high yields. The reactions of para-substituted phenols, 4-methylphenol and 5,6,7,8-tetrahydro-2-naphthol, instead of phenol, effect the selective dichloromethylation at the para-positions. Selective carboxylation of phenol at the 4-position is achieved in the reaction of phenol with carbon tetrachloride in aqueous alkali by using 3-cyclodextrin and copper powder as catalyst. 

The dropwise method gives the results as listed in TABLE VIII. In the absence of CyD, the formylation gives a considerable amount of 3-chloroquinoline as by-product. In the presence of B-CyD, indole-3-aldehyde is obtained 95% yield and 100% selectivity, [11]. 

The ternary inclusion complex of indole, 3 CyD and dichlorocarbene is probably formed in the reaction mixture as shown in Fig. 7. Dichlorocarbene attacks at 3-position to yield indole-3-aldehyde. In the absence jjCyD, dichlorocarbene adds to 2,3- double bond of pyrrole ring. Then, the five-membered ring expands to six-membered ring, resulting 3-chloroquinoline. 3-CyD inhibits sterically the 2,3-double bond addition followed by ring-expansion. 

Indole-3-acetonitrile Indole-3-aldehyde Indole-3-carboxylic acid Indole-3-acetic acid Indole-3-methanol Skatole Tryptophan... 

Likewise, Houben-Hoesch aqrlation (cf. p. 112) of indole gives rise to 3-aqfl indoles. ViLSMEiER formylation ofindole occurs efSdently with DMF/POClj and gives rise (via intermediate 7 and its hydrolysis) to indole-3-aldehyde (8) ... 

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