- AN EFFICIENT AND ENVIRONMENT FRIENDLY PROCESS FOR CHLOROMETHYLATION OF SUBSTITUTED BENZENES
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Disclosed herein is an efficient, environment friendly and commercially viable process for preparation of chloromethylated compound of formula I in substantially pure form and high yield, from the compound of formula II. The process includes contacting the compound of formula II with a chloromethylating agent generated in-situ by reaction of a formaldehyde precursor and hydrogen chloride, in a suitable solvent/contacting medium and in the presence of a catalytic amount of a short chain/low molecular weight carboxylic acid of formula III. I II III wherein, R1, R2, R3 and R4 are as defined in the description.
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Paragraph 0075; 0080
(2020/12/30)
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- Synthetic and mechanistic investigation of piperonyl butoxide from dihydrosafrole
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Piperonyl butoxide (PBO) 1 was prepared via the successive chloromethylation and etherification of dihydrosafrole 3. In this work, during the chloromethylation of 3, several by-products such as 5 (the isomer of chloromethyldihydrosafrole 4), 6-propylpiperonyl alcohol 6, bis(chloromethyl)- dihydrosafrole 7 and 8, bis(2-propyl-4,5-methylenedioxyphenyl)methane 9 and di(2-propyl-4,5-methy lene-dioxybenzyl)ether 10 were found. However, it was found that 5, 6, 7, and 8 could undergo a further reaction to the final product (PBO), rather than its derivatives, though the by-products 9 and 10 still existed. Based on these results, the plausible mechanism of the chloromethylation and etherification of 3 was proposed. Furthermore, the reliability of the plausible mechanism was verified by quantum chemical calculations using DFT. In addition, the final product (PBO) was produced with a high selectivity and yield by reducing the by-products 9 and 10. Springer Science+Business Media B.V. 2011.
- Wang, Shuai,Liu, Jinqiang,Qian, Chao,Chen, Xinzhi
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experimental part
p. 147 - 160
(2012/05/20)
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- Benzodioxale derivatives
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A new benzodioxole derivative has a substituent in the phenyl ring which is a carboxyalkylthioalkyl or the like and is effective to treat a liver disease.
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- Synergistic arthropodicidal compositions and methods of use
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A synergistic arthropodicidal composition comprising (a) a benzodioxole derivative of the formula STR1 in which R represents alkyl, alkenyl, alkynyl, aryl or aralkyl, plus (b) at least one compound selected from (A) carbamates, (B) carboxylic acid esters, (C) phosphoric and phosphonic acid esters and (D) halogenoalkanes, and its use in combating arthropods.
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