Amide synthesis from esters with nitriles under solvent-free conditions using molecular iodine as a catalyst.
The reaction of esters with nitriles, using iodine as a catalyst under solvent-free conditions, was investigated. For example, 1-phenylethyl acetate reacted with benzonitrile in the presence of iodine to afford the amide, N-(1-phenylethyl)benzamide. Addition of water was effective in promoting amidation. The most suitable conditions were investigated, and determined as follows: temperature = 80°C, molar ratio of nitrile:alcohol:iodine:water = 1:3:0.2:1.0, and reaction time = 18 h. The amidation reactivity depended on the stability of the cationic intermediate formed from the ester. Only the reaction of 2-phenylpropan-2-yl acetate with benzonitrile gave no amide compound; rather, the cyclic compound, 1,1,3-trimethyl-3-phenyl-2,3-dihydro-1H-indene was obtained in 90% yield. The reaction of (-)-bornyl acetate with benzonitrile produced the racemic amide compound, (±)-exo-N-isobornylbenzamide, in 82% yield.
Education Center, Faculty of Engineering, Chiba Institute of Technology, Japan.
Yohko
Y
Hanzawa
Yoshio
Y
Kasashima
Kazuki
K
Tomono
Takashi
T
Mino
Masami
M
Sakamoto
Tsutomu
T
Fujita
D000577:Amides / Q000138:chemical synthesis* / Q000737:chemistry; D002384:Catalysis; D004952:Esters / Q000737:chemistry*; D007455:Iodine / Q000737:chemistry*; D009570:Nitriles / Q000737:chemistry*; D010648:Phenylacetates / Q000737:chemistry; D012997:Solvents / Q000737:chemistry*
D000577:Amides; D004952:Esters; D009570:Nitriles; D010648:Phenylacetates; D012997:Solvents; D007455:Iodine; C014356:benzonitrile; C521816:ethyl phenylacetate