GB654980A - Improvements in and relating to the production of bodies adapted for use as insecticides - Google Patents

Abstract

Insecticidal compositions are produced by a process comprising catalytically hydrogenating pyridine or its homologues or catalytically dehydrogenating piperidine hydrogenated quinoline or hydrogenated isoquinoline or their homologues optionally in the presence of hydrogen and recovering an insecticidal mixture of condensation products boiling above about 275 DEG C. by fractionation. According to the Provisional Specification the mere treatment of the above classes of compounds with hydrogenation or dehydrogenation catalysts respectively enables high boiling insecticidal materials to be produced and quinoline and isoquinoline are included as starting materials and the use of hydrogen in either process appears optional. The process may be carried out in either liquid or vapour phase and the hydrogenation or dehydrogenation catalyst employed appears unimportant. Nickel, particularly Raney nickel, is a suitable catalyst showing both hydrogenation and dehydrogenation activity according to temperature. In the vapour phase operation a nickel cage may be used and Raney nickel in the liquid phase operation. Mixtures of tertiary nitrogenous cyclic bases may be used such as mixtures of pyridine and piperidine. In examples (1) pyridine vapour and hydrogen are passed over a nickel cage catalyst at elevated temperature and pressure to obtain a product containing 90 per cent piperidine and from which 5 per cent of insecticidal material is obtained by fractionation at atmospheric pressure; (2) piperidine is heated at elevated pressure in the pressure of Raney nickel with hydrogen and the products are fractionated to obtain insecticidal material boiling over 275 DEG C.ALSO:An insecticidal mixture of condensation products boiling above about 275 DEG C. is obtained by fractionation of products obtained by catalytically hydrogenating pyridine or its homologues or catalytically dehydrogenating, optionally in the presence of hydrogen, piperidine, hydrogenated quinoline or hydrogenated isoquinoline or their homologues (see Group IV(b). According to the provisional Specification the mere treatment of the above classes of compounds and quinoline and isoquinoline also with hydrogenation or dehydrogenation catalysts respectively, yields high boiling insecticidal materials, and the use of hydrogen is optional. Material boiling over 275 DEG C. having insecticidal properties is obtained by fractionating products obtained in p examples (I) by hydrogenating pyridine using a nickel catalyst; (II) by heating pyridine with hydrogen in the presence of Raney nickel.