The Synthesis And Biological Activity Of4-(7-Alkoxy-2,2-Dimethyl-2,3-Dihydrobenzofuran-5-yl)-2-Acylaminothiazole

Benzofuran derivatives and thiazole derivatives exhibit good insecticidal andfungicidal activities. In order to search for novel compounds with higher activity, wedesigned and synthesized a series of new compounds containing the benzofuran ring,thiazole ring and acylamino by following the principle of Substructure Link Way.Synthesis of2-bromo-1-(7-alkoxy-2,2-dimethyl-2,3-dihydrobenzofuran-5-yl)ethanone/propan-1-one (3): Compounds3were synthesized from2,2-dimethyl-2,3-dihydro-7-benzofuranol by etherification, Friedel-Crafts acylation and α-bromationreaction. Besides, the effect of different catalysts on the acylaction was investigated.The structures of the compounds were characterized by1H NMR.Synthesis of4-(7-alkoxy-2,2-dimethyl-2,3-dihydrobenzofuran-5-yl)-2-acylamino-thiazole (5): Compounds5were synthesized from compounds3by cyclization withthiourea and then with anhydride/acylchloride. The structures of the compounds werecharacterized by1H NMR and compound5q was also clearly characterized by13CNMR,1H,1H COSY, HMQC and HMBC.5a~5x were tested for the insecticidal and fungicidal activities and thestructure-activity relationship was also discussed. The preliminary bioassays forinsecticidal activity among compounds5a~5x indicated that the mortality rate of5eagainst Tetranychus urticae and5d against Aphis fabae were58.0%and49.9%at500mg/L respectively, and5a~5x had no toxicity on Mythimna sepatara at the sameconcentration. The results of fungicidal screening among5a~5x revealed that theinhibition rates of5e,5p and5q against Rhizoctonia solani reached up to95.0%at25mg/L. The inhibition rates of5h and5u against Sclerotonia sclerotiorum were82.3%and75.9%. The inhibition rates of5k~5m and5t~5v against Blumeria graminis weremore than70.0%. The fungicidal activity of compounds5e,5h,5l,5m,5p,5q,5t and5u was stronger when R3means CH3and CH3ClCH.