76989-09-8Relevant academic research and scientific papers
Preparation of alkyl-substituted indoles in the benzene portion. Part 7. Synthesis of (±)- and (S)-(-)-pindolol
Fuji,Muratake,Akiyama,Natsume
, p. 2353 - 2357 (2007/10/02)
A new, short-step synthesis of a β-adrenergic blocking agent, pindolol, 1-(4-indolyloxy)-3-(2-propylamino)-2-propanol, is described. The acid-catalyzed indole cyclization reaction of 4-[1-(4-methylphenyl)sulfonyl-3-pyrrolyl]-4-oxobutanal (14) in the presence of (±)-3-chloro-1,2-propanediol (12) and (R)-1-O-[(4-methylphenyl)sulfonyl]glycerol (24) afforded (±)-1-chloro-3-[1-(4-methylphenyl)sulfonyl-4-indolyloxy]-2-propanol (15) and (R)-(-)-3-[1-(4-methylphenyl)sulfonyl-4-indolyloxy]-1-[(4-methylphenyl sulfonyloxy]-2-propanol (25). Reaction of these with isopropylamine and removal of the protecting group at the indole nitrogen gave (±)- and (S)-(-)-pindolol (3 and 4), thus constituting an efficient three-step synthesis of 3 and 4 from the readily available aldehyde (14).
Preparation of alkyl-substituted indoles in the benzene portion. Part 8. Improved practical synthesis of 4,4-dialkoxy-1-(1-arylsulfonyl-3-pyrrolyl)-1-butanone and 4-(1-arylsulfonyl-3-pyrrolyl)-4-oxobutanal, and a novel synthetic procedure for 4-alkoxyindole derivatives
Utsunomiya,Muratake,Natsume
, p. 2358 - 2361 (2007/10/02)
Important precursors (1 and 2) for the synthesis of 4-substituted indole derivatives were readily obtained by acid treatment of a tosylamide (13), which was prepared in a single operation by treatment of 10 with N-tosyl-N',N'-dimethylformamidine (TsN=CHNMe2). Compound (10) was effectively synthesized from nitromethane and acrolein by way of a nitro compound (15). A novel indole formation reaction from the tosyl-amide (13) to gain short access to 4-alkoxyindoles, such as 16, 17, 19, and 21 is presented.
