Background and overview[1]
3-iodobenzyl alcohol can be used as a pharmaceutical synthesis intermediate. It can be prepared from m-iodobenzoic acid methyl ester as the reaction raw material. It can be used to prepare new dihaloacetylated heterocythrins. At present, pyrethroids are almost used in All crops, nurseries, various urban structures and landscaping sites, construction sites (pre-construction termiticides), home/garden environments and many other locations.
Preparation[1]
Put m-iodomethyl benzoate (1.0eq.) into a 100mL round-bottomed flask, add a magnetic stirrer, remove oxygen with N2, plug the rubber stopper, and insert N2 balloon, use a syringe to add an appropriate amount of dried toluene as the solvent, stir evenly, then use a syringe to add LiBH4(inTHF) (2.0M, 1.0~2.0eq.), and then move the system into React for 1 hour in an oil bath at 100°C, and confirm whether the reaction is complete by spotting (TLC method). When the reaction is complete, slowly add excess 5% dilute hydrochloric acid as a quencher until no bubbles are generated in the reaction system. Then, the reaction system was distilled under reduced pressure using a rotary evaporator and the solvent was almost completely dried, and then extracted three times with ethyl acetate. The organic phase was collected, dried over anhydrous magnesium sulfate, filtered, the filtrate was collected, and the solvent was evaporated to dryness under reduced pressure. The crude product was purified by column chromatography (dry loading, eluent: petroleum ether/ethyl acetate = 3/1 (volume ratio) Rf = 0.) to obtain a clear light yellow liquid, that is, the product 3-iodine was obtained Benzyl alcohol.
Apply[1]
3-iodobenzyl alcohol can be used to prepare new dihaloacetylated heterocythrins: Weigh a certain amount of dibromethrin (1.0eq.) into a 100mL round-bottomed flask, add a magnetic stirrer, Use N2 to remove oxygen, plug the rubber stopper, and insert the N2 balloon. Use a syringe to add an appropriate amount of anhydrous dichloromethane (DCM) as the solvent, and then Add oxalyl chloride (1.5g/mL, 1.0~3.0eq.) and 0.1mL anhydrous N,N-dimethylformamide (DMF) with a syringe, and activate at room temperature for 3 hours. Directly evaporate the solvent under reduced pressure without taking out the magnetic stirrer. Quickly plug in the rubber stopper and insert the N2 balloon. Then dissolve it with an appropriate amount of anhydrous dichloromethane and add pyridine ( 0.9827g/mL, 1.0~3.0eq.), reaction for 1h. Subsequently, 3-iodobenzyl alcohol (0.5~1.0eq.) obtained after reduction was added, the reaction was carried out at room temperature for 24 hours, and the reaction end point was detected by TLC. Subsequently, remove the reaction flask, use a magnet to take out the magnetic stirrer, and wash the stirrer multiple times with methylene chloride. The washing liquid is filled in the original reaction flask. The reaction system is distilled under reduced pressure using a rotary evaporator and the solvent is basically completely dried. Extract three times with ethyl acetate, collect the organic phase, dry with anhydrous magnesium sulfate, filter, collect the filtrate, evaporate the solvent under reduced pressure, and then perform silica gel column chromatography purification (dry loading, eluent: petroleum Ether/ethyl acetate = 30/1 (volume ratio) Rf = 0.417) to obtain C15H15Br2IO2.
References
[1] CN201910044358.7 A new type of dihaloacetylated heterocythrin and its preparation method and application
