Tertiary esters of indolyl aliphatic acids and their production

摘要

Tertiary a -(3-indolyl) aliphatic esters of formula where each of R and R1 is a hydrogen atom or a C1- 8 alkyl; each R2 is a hydrogen or halogen atom or a C1- 8 alkyl, C1- 8 alkoxy, halogenated alkyl, hydroxy, nitro, cyano, amino, substituted amino, aminomethyl, substituted aminomethyl, dialkylsulphonamido, mercapto, or alkylmercapto radical; and each of R3, R4, R5 is an alkyl, alkoxyalkyl, aralkyl, aryl or aralkyl radical or R3 and R4, together with the tertiary ester carbon atom, represent a cycloalkyl or cycloalkenyl radical and R5 is a C1- 8 alkyl radical, are prepared by reacting a phenyl hydrazine addition salt, where R2 is as previously defined and HX represents an acid with ionization constant of at least 10-5, with a y-keto acid tert.-ester in an organic solvent in the absence of a catalyst. Examples describe the preparation of t.-butyl 2-methyl-5-methoxy, -butoxy, -propoxy, and ethoxy-3-indolyl acetates; 2-methyl-3-indolylacetic acid t.-butyl ester; 2-methyl-5-fluoro and 5-trifluoro methyl-3-indolylacetic acid t.-butyl esters; 2-methyl, -ethyl and butyl-5-alkyl-3-indolylacetic acid t.-butyl ester; 2-methyl-5-dimethylamino-3-indolyl acetic acid t.-butyl ester; 2-methyl-5-dimethylsulphonamino- and 2-methyl-5-diethylamino-3-indolyl acetic acid t.-butyl esters; 2-methyl-5-nitro-and 5-cyano-3-indolyl acetic acid t.-butyl ester; 2-ethyl, 2-propyl and 2-butyl-5-methoxy-3-indolylacetic acid t.-butyl ester; a -(2-methyl-5-methoxy-3-indoyl) propionic, butyric, pentanoic and caproic acid t.-butyl esters; 2-methyl-5-alkoxy-3-indolyl acetic triphenyl methyl esters; 2,4,5 - trimethyl - 7 - chloro - 3 - indolylacetic acid t.-butyl esters and other compounds are listed. g -Keto acid tertiary esters of formula where each of R and R1 is a hydrogen atom or a C1- 8 alkyl radical and each of R3, R4, R5 is an alkyl, alkoxy, aralkyl, aryl or alkaryl radical or R3 and R4 together with the tertiary ester carbon atom represent a cycloalkyl or cycloalkenyl radical and R5 is a C1- 8 alkyl radical in particular, tert. alkyl levulinates, tert. butyl levulinates and triphenyl methyl levulinate are claimed and they are prepared by reacting a g -keto acid under acidic conditions with a tert. olefine where R15 is a radical capable of becoming an alkyl, alkoxyalkyl, or aralkyl radical upon addition of a hydrogen atom. An organic solvent is used and an acid catalyst may be present. The keto-acid may also be reacted with alkylene cycloalkanes or cycloalkylenes or an alkyl cycloalkene-1. Alternatively the corresponding keto acid chloride may be reacted with an alkali tert. alkoxide in anhydrous benzene, or with a tert. alkanol in the presence of a halogen acid acceptor such as tert. amines. A salt of the corresponding keto acid, preferably the silver or ammonium salt, may be treated with a triacylated halomethane in benzene under anhydrous conditions.