3-Indole butanoic acid

An interesting one-pot hydroformylation/Fischer indole sequence can be achieved by running the hydroformylation in the presence of a phenylhy-drazine. This protocol gave access to the methyl ester of the plant growth regulator 3-indole butanoic acid (IBA) (Scheme 16) [61-63]. A review on related tandem processes involving the hydroformylation as a key step has appeared recently [9]. 

Methyl-lf/-indol-l-yl)butanoic acid 135 easily prepared from 3-methylindole and dihydro-2(3//)-furanone, was used in the synthesis of natural 12//-pyrido[l,2- 7 3,4-/ ]diindoles which have antimicrobial activity and are cytotoxic against L-1210 mouse leukemia (Equation 25) <1996TL5207>. 

C12H13N02 1 H-indole-3-butanoic acid 133-32-4 407.65 35.087 2 23987 C12H1403 4-allyl-2-methoxyphenyl acetate 93-28-7 554.15 49.111 1,2... 

Using odor activity value (ratio of concentration to odor threshold), Forss et al. (23), Urbach et al. (24), and Stark and co-worker (25-27) reported 5-decalactone, 8-octalactone, decanoic acid, dodecanoic acid, skatole, and indole as important contributors to the flavor of butter oil. In addition, the data of Siek et al. (28) indicated that in fresh butter, the levels of butanoic acid, caproic acid, 5-decalactone were above their taste threshold. 

Aspartic acid, /V-(1H-indol-3-ylacetyl)-80-60-4 Butanoic acid, 2-amino-... 

Hydroxy-1 -(1 //-indol-3-y l)-4-methy 1-3-pentanone, H-30162 l//-Indole-3-butanoic acid Et ester, in 1-30013... 

Another of the arylalanines, L-tryptophan, was used at the same laboratories [81] for the synthesis of novel benzazepines (56) as dual inhibitors of ACE and thromboxane synthase (Scheme 5.25). Ozonolysis of 7V-acetyl l-tryptophan to effect scission of the indole ring followed by 7V-protection gave the 4-keto acid (57) as a cyclization precursor. Downstream transformations included diastereoselective reduction of the ketone functionality and reductive alkylation of the amine substituent with ethyl 2-oxo-4-phenyl-butanoate. 

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