A Synthesis of New 2-Iminothiazolines and Their Antifungal Activities (II)

새로운 2-이미노티아졸린 유도체의 합성과 항균활성 (II)

A synthesis and the screening of new 2-iminothiazolines (IV) of which structures are modified based on a lead compound, thiazoline for development of new agrochemical fungicide were described. Bromination of acetoacetanilides (I) which were prepared by the reaction of diketene with anilines gave the corresponding ${\gamma}-bromoacetoactanilide\;(II)$. Treatment of II with N-phenyl-N'-methyl thiourea (III) afforded IV, structure of which was confirmed by various spectroscopic methods. Antifungal activity of the new IV was tested against six kinds of typical plant diseases (in vivo). The IV with aromatic substituents showed remarkable activity against the Pyricuraria oryzae at 250 ppm in primary screening. The candidates with control value over 90% in primary screening were selected and further tested for second screening at lower concentrations. The IV which has an electron-withdrawing substituent such as halogen, especially fluorine in aryl group showed a higher activity as compared to those with electron-donating group and meta substituent was for optimal position.

신 농약을 개발할 목적으로 선도화합물인 티아졸린의 곁가지를 변화시킨 새로운 2-이미노티아졸린 유도체를 합성하여 항균활성을 검색하였다. 디키틴과 아닐린으로부터 제조된 아세토아세트아닐리드 유도체를 브롬화하여 상응하는 감마-브로모아세토아세트아닐리드 유도체를 얻고 이를 티오우레아 유도체와 반응시켜 2-이미노티아졸린 유도체를 합성하였다. 2-이미노티아졸린의 항균활성을 검색하고자 6 종류의 대표적인 식물 병원균에 대한 시험(in vivo)을 하였다. 2-페노치환체들은 벼도열병균에 대하여 250 ppm에서 탁월한 항균성을 나타냈다. 1차 활성시험에서 방제가 90이상으로 평가된 것만 선발하여 2차 활성시험(농도저하 시험)을 수행하였다. 2-아릴기에 전자주게보다 전자 끌게, 전자끌게 중에서도 할로겐치환체가 도입된 경우에 고 활성을 나타냈으며 불소원자가 치환된 경우에 활성이 비교적 양호하였다.