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Study up on Flumetralin for Controlling the Growth of Tobacco Suckers

Author: DaiJiaSheng
Tutor: ChenXinZhi
School: Zhejiang University
Course: Chemical Engineering
Keywords: fumetralin tobacco inhibitor 3-chloro-2-methylaniline diazotization 2-chloro-6-fluorotulene chlorination 2-chloro-6-fluorobenzyl chloride animation N-ethyl-2-chloro-6-fluoro-benzylamine synthesis analysis bioactivity
CLC: TQ459
Type: Master's thesis
Year: 2002
Downloads: 167
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Abstract

The flumetralin is a high efficient agent for controlling the growth of tobacco suckers. A novel synthesis route was proposed based on literatures and comprehensive comparison. This route started from 3-chloro-2-methylaniline as a raw material. Through diazo fluorination with fluoroboric acid and side chain photochlorination. benzylamine was obtained by reacting with monoethylamine. Flumetralin was eventually prepared by reacting with 4-chloro-3,5-dinitro--benzotri fluorideDiazotization of 3-chloro-2-methylaniline with hydrochloric acid, sodium nitrite and fluoroboric acid took place at 0-5C. Then 2-chloro-6-fluorotulene was produced through pyrogenation and distillation of the dry diazonium borofluoride. The yield of 2-chloro-6-fluorotulene was 81.3%. and purity reached 99.5%. The trifluoroboride formed in pyrogenation process was absorbed by hydrofluoric acid and converted to fluoroboric acid for recycle.2-chloro-6-fluorobenzyl chloride was prepared by photochlorination of 2-chloro-6-fluorotulene. The chlorination was controlled at 65-70%, the reaction temperature of 140C was preferable. Under above condition, after 3. o hours of reaction, the yield of the reaction reached 92. 7% and the average concentration of the product was 95.6%.The synthesis of N-ethyl-2-chloro-6-fluoro-benzylamine took place by reacting 2-chloro -6-fluorobenzyl chloride with excessive monoethylamine in the solution of sodium hydroxide which was used as the ultimate proton acceptor. Yield of the reaction reached 91.7%. The ratio of monoethylamine to 2-chloro-6-fluorobenzyl chloride was 4.5:1, excessive monoethylamine was used so as to effectively suppress the formation of side product of dibenzylamine.Flumetralin was prepared by reacting N-ethyl-2-chloro-6-fluoro-benzylamine with 4-chloro-3,5-dinitro-benzotrifluoride in absence of solvents. The yield of flumetralin reached 94.2%. the purity of flumetralin was 98.5%. The overall yield based on 3-chloro-2-methylaniline as a raw material was 65.19%.Quantitative analysis of flumetralin was undertaken with 5% OV-17 Packed column and di-n-butyl phthalate was selected as an internal lane standard. Intermediates could also be analyzed with the same column when analysis conditions were appropriately changed. The prepared fumetralin matched the expected structure by confirmation of IR. UV. element analysis, mass spectrum, and nuclear magnetic resonance.25% fumetralin EC was made by mixing with proper solvents and emulgents and was proved to have the same effect as 25% prime EC. It showed that the quality of the tobacco was improved and production increased after using this product.

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