ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Synthesis and herbicidal activity of 1-ethynylcyclohexanol derivatives

M. Furdík, P. Rapoš, A. Štullerová, and S. Priehradný

Komensky University, Bratislava

Abstract: Starting from 1-ethylylcyclohexanol (I) and bis(1-hydroxycyclohexyl)acetylene (II), compds. IIa and IIb were prepd. and their herbicide activities were tested. IIa (X, R, m.p., or b.p., and % yield given): NH, Ph, 96-7°, 53 (III); NH, p-ClC₆H₄ (IV), 107-8°, 60.1; NH, m-ClC₆H₄ (V), 79-80.5°, 62; NH, m-ClC₆H₄ (VI), 118-19°, 70; NH, 2,5- Cl₂C₆H₃ (VII), 84.5-5.5°, 63; O, Me (VIII), b16 110-12°, 64; O, Et (IX), b0.05 67-70° 58.5; O, Pr (X), b14 129-31°, 60.2; O, CH₂CH:CH₂ (XI), b17-18 132-5°, 75.7; (XR =) CH₂Cl (XII), b0.01 59-61°, 63.5; (XR = CCl₃) (XIII), b0.08 80-1°, 72.2. IIb (R', m.p., and % yield given): Ph (XIV), 191-2.5°, 64; m-ClC₆H₄ (XV), 205.5-207°, 61. An Et₂O soln. of 0.5 mole tert-BuOK was satd. with dry C₂H₂ at -15° and simultaneously with passing C₂H₂ through the soln., a soln. of 0.5 mole cyclohexanone in 100 ml. abs. Et₂O was added dropwise, and a stoichiometric amt. of aq. NH₄Cl was added to liberate I. Distn. gave 76% I, b15 76.5-7°, together with 4.4 g., II, m. 109-9.5°. When C₂H₂ and Et₂O soln. of 1 mole of cyclohexanone were simultaneously added to a soln. of 1 mole tert-BuOK in Et₂O at -15° and the obtained mixt. treated with aq. NH₄Cl, 53.2% II, m. 109-9.5° (C₆H₆, petr. ether) resulted. The compds. III-VII were prepd. as follows. To a soln. of 0.025 mole I in 5 ml., abs. C₅H₅N was added 0.025 mole corresponding phenyl isocyanate, the mixt. boiled 15 min., and then allowed to stand 2 hrs., at room temp. After pouring the mixt. into 40 ml. H₂O with 5 ml. concd. HCl, the product was sepd. and recrystd. from n-hexane. Similarly were prepd. XIV and XV from II. Molar ratio of II to corresponding phenyl isocyanate was 1:2. The compds. VIII-XI were prepd. as follows. Na (1.1 g.) was dispersed in 50 ml., C₆H₆ and to this mixt. added dropwise during 20 min. at room temp. a soln. of 7.2 g. I in 10 ml. abs. C₆H₆. The Na salt of I was stirred 2 hrs., 0.055 mole of a corresponding chloroformate was added dropwise, the mixt. heated on a water bath 2 hrs., allowed to stand overnight, then washed with H₂O, and the C₆H₆ layer sepd. and distd. XII and XIII were prepd. by treating I as follows. The appropriate acetyl chloride (0.1 mole) was added to a mixt. of 0.1 mole C₅H₅N in 90 ml. C₆H₆ at 0°, a soln. of 0.1 mole I in 30 ml. abs. C₆H₆ added dropwise during 15 min., the mixt. heated 1 hr. at 60°, cooled to -15°, the solid filtered off and washed with C₆H₆, the filtrate washed with aq. NaHCO₃ to neutral reaction, and the C₆H₆ layer sepd., dried and distd. to give the product. Tests proved I to be the most active as a herbicide. The herbicidal properties of all the other compds. described were comparable with those of known herbicide standards 2,4-D (Agrion), Na salt of DNCK (Rafex), and CMU (Monuron).

Full paper in Portable Document Format: 179a616.pdf (in Slovak)

Chemical Papers 17 (9) 616–628 (1963)