Beta-Alanine → 2-Benzylidene-4-methyl-3-oxo-N-phenylpentanamide

Beteiligte Stoffe

Reaktionsschritte

4-Methyl-3-oxo-N-phenylpentanamide (XIX) is obtained by heating a mixture of methyl 4-methyl-3oxopentanoate (XX), airline and ethylene diamine in toluene. 4-Methyl-3-oxo-N-phenylpentanamide (XIX) is subsequently reacted with benzaldehyde in the presence of a catalyst such as, for example, piperidine and glacial acetic acid, ethylene diamine and glacial acetic acid, β-alanine and glacial acetic acid, and the like in an inert solvent such as, for example, toluene, heptane, hexane, and the like for about 24 to about 36 hours at about 60° to about 120° C. with the removal of water to afford 4-methyl-3-oxo-N-phenyl-2-(phenylmethylene)pentanamide (XVIII). Preferably the reaction is carried out with β-alanine and glacial acetic acid at reflux for about 24 hours in hexane. The 4-methyl-3-oxo-N-phenyl-2-(phenylmethylene)pentanamide (XVIII) is reacted with 4-fluorobenzaldehyde in the presence of a catalyst such as, for example, 3-benzyl-5-(2-hydroxyethyl)-4-methylthiazolium chloride, 3,4-dimethyl-5-(2-hydroxyethyl)thiazolium iodide, 3-ethyl-5-(2-hydroxyethyl)-4-methylthiazolium bromide, thiamine hydrochloride, and the like, and a base such as, for example, N,N-diisopropylethyamine, pyridine, N,N-dimethylaniline, triethylamine, 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU), 1,4-diazabicyclo2.2.2]octane (DABCO), 4-dimethylaminopyridine (DMAP), N,N,N',N'-tetramethylethylenediamine (TMEDA) and the like, either neat or in the presence of a solvent such as, for example, tetrahydrofuran, tertiary-butyl methyl ether, ethanol, dimethylformamide, dimethylsulfoxide, N-methylpyrrolidone, acetonitrile, methylisobutyl ketone, ethyl acetate, isopropanol, pyridine and the like for about 20 to about 30 hours under anhydrous conditions at about room temperature to about the reflux temperature of the solvent to afford the compound of Formula XVII. Preferably the reaction is carried out in the presence of 3-ethyl-5-(2-hydroxyethyl)-4-methylthiazolium bromide and triethylamine in ethanol at about 75°-80° C. for about 24 hours. The compound of Formula XVII is reacted with a compound of Formula ##STR45## wherein R10 and R11 are alkyl of one to eight carbon atoms or R10 and R11 together are ##STR46## --CH2CH2 -- or --CH2CH2CH2 -- in the presence of a catalyst of Formula

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