Synthesis And Bioactivities Of 3-acyl-4-hydroxylpyrroline-2-one Derivatives

Tenuazonic acid (TA), named 5-sec-but-3-acetyl-4-hydroxylpyrrolin-2-one, was first derived from the culture filtrate of Alternaria tenuis in 1957. Its structure was firstly confirmed by Stickings in 1959. Tenuazonic acid and iso-Tenuazonic acid from the culture filtrates of Alternaria alternata have broad-spectrum and high-efficient herbicidal activities. In this paper, TA derivatives 3-acyl-4-hydroxylpyrroline-2-ones and their herbicidal activities and the antifuginal activities were researched in order to screen new compounds with high activity, low toxicity and easily disaggregated property.First, the synthesis of 3-acyl-4-hydroxylpyrrolin-2-ones were studied. Amino acid methyl ester hydrochlorides were synthesized by methanol reacting with amino acids, diketene was added in ice-bath after dehydrochlorination with NaOMe to give N-acetoacetyl amino acid methyl esters. Then N-acetoacetyl amino acid methyl esters were cyclized in the MeOH-benzene solution of MeONa to obtain 3-acetyl-4-hydroxyl-5-alkyl(H)pyrrolin-2-ones 1-3. The compound 3-acetyl-4-hydroxylpyrrolin-2-one 1 and substituted benzaldehyde was refluxed in the ethanol acetchlorin to give 3-acetyl-4-hydroxyl-5-benzylidenepyrrolin-2-ones 4-7. Moreover, substituted amines and ethyl chloroacetate were refluxed in ethanol to prepare substituted aminothylacetates, the substituted-aminoethylacetate was reacted with diketene and ethyl benzoylacetate respectively to give N-alkyl-3-acetyl-4-hydroxylpyrrolin-2-ones 8-16 and N-aryl-3-benzoyl-4-hydroxylpyrrolin-2-ones 17-20 after next steps cyclization, acidification. The structures of all the compounds were confirmed by IR, MS and 1H NMR.The herbercidal activities against Brassica napus, Echinochloa crusgalli and antifungicidal activities against Fusarium graminearum, Botrytis cinera and Rhizoctonia cerealis were evaluated preliminarily. The result indicated that all the compounds didn't show any inhibition to the bud of Echinochloa crusgalli, but some of the compounds have the inhibiting effect towards the root of Brassica napus and the root of Echinochloa crusgalli. The inhibition rates of compound 15 and 19 to the Brassica napus were over 80%, the inhibition rates of compound 3,8,11 and 15 to the Echinochloa crusgalli were over 90%. Fungicidal activities of the compounds were determined by radial growth inhibition method, the results indicated that some of the compounds showed certain fungicidal activities, thereinto the coumpound 16 exhibited the inhibition rate of 81.1% against Botrytis cinera.