Ethynylation of diene adducts with methyl vinyl ketones and with N-substituted maleimides. Herbicide activity of final productsV. Sutoris and M. Furdík Comenius University, Bratislava
Abstract: The synthesis of ethynylcarbinols by the ethynylation of the exocyclic ketones and bicyclic dicarboximides with Li-Al-acetylene complex in dry tetrahydrofuran and their herbicide activity was described. The exocyclic ketones were prepd. by Diels-Alder reaction of 1,3 dienes (cyclopentadiene, tetrachlorocyclopentadiene, hexachlorocyclopentadiene, isoprene and chloroprene) with H2C:CHCOMe. The following I were prepd. (R, R1, R2, R3, and b.p./torr given): H, H, H, C≡CH (Ia), 73-6°/2; H, H, H, Et, (Ib), 88°/9; H, Cl, Cl, C≡CH, 130-3°/1.5; Cl, Cl, Cl, Et, 153°/6; and the following II (R, R1 and b.p./torr given): Me, H (IIa), 84-6°/1.5; Me,COCH2Cl, 129°/1; Cl, H (IIb), 103-5°/3; Cl, COCH2Cl, 132°/1; and III, b. 60-2°/1 torr; and IV (R = iso-Pr), m. 168°, and IV (R = Ph), m. 192°. Ia was also prepd. by the Grignard reaction. It was detd. that the high yields 82-5% were obtained at the ethynylation of chloroprene and isoprene, which lack the endo-bridge causing the space obstruction. With the hexachloropentadiene contg. endo-dichloromethylene bridge, no ethynylated product was obtained either with Li-Al-acetylene complex or with the Grignard reaction. Herbicidal activity Ia compares favorably with 2,4-D; it decreases in the order: IIa, III, Ib, IIb. The phytotoxic effect on the agricultural plants is discussed. 5 tables are given. Full paper in Portable Document Format: 215a329.pdf (in Slovak)
Chemical Papers 21 (5) 329–339 (1967) |
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