An environmentally benign and practical preparation method for the Vilsmeier-Haack reagent (VH) has been developed by using phthaloyl dichloride with DMF in toluene or 2-chlorotoluene. Phthalic anhydride as the byprod...An environmentally benign and practical preparation method for the Vilsmeier-Haack reagent (VH) has been developed by using phthaloyl dichloride with DMF in toluene or 2-chlorotoluene. Phthalic anhydride as the byproduct was recovered in high yield by simple filtration. Some aromatic acids have been transformed into the corresponding acid chlorides in good yields by employing the isolated VH. Treatment of primary or secondary alcohols with VH gave alkyl formates or alkyl chlorides by depending on the reaction conditions.展开更多
Nitration of aromatic Compounds is triggered by Vilsmeier-Haack reagent (DMF/POCl3) or (DMF/SOCl2) in the presence of KNO3 or NaNO2 under conventional and non-conventional conditions. The reactions af- forded correspo...Nitration of aromatic Compounds is triggered by Vilsmeier-Haack reagent (DMF/POCl3) or (DMF/SOCl2) in the presence of KNO3 or NaNO2 under conventional and non-conventional conditions. The reactions af- forded corresponding Nitro derivatives in very good yield with high regioselectivity. The results obtained in non-conventional methods (Micro wave irradiation, Grinding, Sonication) are comparable with those ob- tained under conventional conditions, but the reaction times of former conditions are substantially shorter than that of the latter.展开更多
Sulfonation of aromatic compounds (Phenols, Anilines) is triggered by Vilsmeier Haack (VH) reagent (DMF/POCl3) or (DMF/SOCl2) in the presence of NaHSO3 under Sonication and conventional stirred conditions at room temp...Sulfonation of aromatic compounds (Phenols, Anilines) is triggered by Vilsmeier Haack (VH) reagent (DMF/POCl3) or (DMF/SOCl2) in the presence of NaHSO3 under Sonication and conventional stirred conditions at room temperature. The reactions afforded corresponding Sulfonic acid derivatives in very good yields. The results obtained under Sonication were enhanced when compared with the yields of the conventional method.展开更多
Acetylation and benzoylation reactions of certain aromatic aldehydes, ketones with Vilsmeier-Haack Re- agents using Acetamide and Oxychloride (SOCl2 or POCl3) under conventional (thermal) and non conven- tional [micro...Acetylation and benzoylation reactions of certain aromatic aldehydes, ketones with Vilsmeier-Haack Re- agents using Acetamide and Oxychloride (SOCl2 or POCl3) under conventional (thermal) and non conven- tional [microwave irradiated (MIR), ultrasonic assisted and solvent free mortar pestle (grinding)] conditions. Reactions afforded good to excellent yields of products with both the VH reagents, reaction times were fairly less in the case of [amide/POCl3] than those of [amide/SOCl2] reagent. Reactions are dramatically acceler- ated in under sonicated and microwave irradiations with a trend: MIR (few seconds) >> Sonication (minutes) > Grinding (min) >> thermal (several hrs).展开更多
Formamidine derivatives could be used as the building blocks for substituted heterocyclic compounds with various biological activities. N＇-Aryl-N,N-dimethylformamidinium chlorides have been synthesized in high yields...Formamidine derivatives could be used as the building blocks for substituted heterocyclic compounds with various biological activities. N＇-Aryl-N,N-dimethylformamidinium chlorides have been synthesized in high yields by reaction of aromatic primary amines with Vilsmeier-Haack reagent at room temperature. The structures of all the new compounds were identified by ESI-MS, IR and NMR spectra. The steric structures of some of these compounds were clarified by X-ray single crystal analysis.展开更多
以3,4,5-三甲氧基甲苯(TMT)为原料,先由V ilsm e ier-Haack反应合成6-甲基-2,3,4-三甲氧基苯甲醛,然后在对甲基苯磺酸催化下经Dak in反应将其氧化为6-甲基-2,3,4-三甲氧基苯酚,最后用重铬酸钠催化氧化合成了辅酶Q0,过程总收率达到72.3%...以3,4,5-三甲氧基甲苯(TMT)为原料,先由V ilsm e ier-Haack反应合成6-甲基-2,3,4-三甲氧基苯甲醛,然后在对甲基苯磺酸催化下经Dak in反应将其氧化为6-甲基-2,3,4-三甲氧基苯酚,最后用重铬酸钠催化氧化合成了辅酶Q0,过程总收率达到72.3%。经正交实验得V ilsm e ier-Haack反应的最佳工艺为:n(TMT)∶n(POC l3)∶n(DMF)=1∶1.8∶2.2,反应温度70℃,反应时间7 h。在此工艺条件下,此步反应收率可达93.2%,w(6-甲基-2,3,4-三甲氧基苯甲醛)=98.5%;在Dakin反应中,以w(H2O2)=30%为氧化剂,30℃为最佳反应温度,反应时间1.5 h。展开更多
文摘An environmentally benign and practical preparation method for the Vilsmeier-Haack reagent (VH) has been developed by using phthaloyl dichloride with DMF in toluene or 2-chlorotoluene. Phthalic anhydride as the byproduct was recovered in high yield by simple filtration. Some aromatic acids have been transformed into the corresponding acid chlorides in good yields by employing the isolated VH. Treatment of primary or secondary alcohols with VH gave alkyl formates or alkyl chlorides by depending on the reaction conditions.
文摘Nitration of aromatic Compounds is triggered by Vilsmeier-Haack reagent (DMF/POCl3) or (DMF/SOCl2) in the presence of KNO3 or NaNO2 under conventional and non-conventional conditions. The reactions af- forded corresponding Nitro derivatives in very good yield with high regioselectivity. The results obtained in non-conventional methods (Micro wave irradiation, Grinding, Sonication) are comparable with those ob- tained under conventional conditions, but the reaction times of former conditions are substantially shorter than that of the latter.
基金Project supported by the National Natural Science Foundation of China(No.20572079)the Natural Science Foundation of Zhejiang Province(No.Y407079)the Foundation of Science and Technology Department of Zhejiang Province(No.2007C21116).
文摘Sulfonation of aromatic compounds (Phenols, Anilines) is triggered by Vilsmeier Haack (VH) reagent (DMF/POCl3) or (DMF/SOCl2) in the presence of NaHSO3 under Sonication and conventional stirred conditions at room temperature. The reactions afforded corresponding Sulfonic acid derivatives in very good yields. The results obtained under Sonication were enhanced when compared with the yields of the conventional method.
文摘Acetylation and benzoylation reactions of certain aromatic aldehydes, ketones with Vilsmeier-Haack Re- agents using Acetamide and Oxychloride (SOCl2 or POCl3) under conventional (thermal) and non conven- tional [microwave irradiated (MIR), ultrasonic assisted and solvent free mortar pestle (grinding)] conditions. Reactions afforded good to excellent yields of products with both the VH reagents, reaction times were fairly less in the case of [amide/POCl3] than those of [amide/SOCl2] reagent. Reactions are dramatically acceler- ated in under sonicated and microwave irradiations with a trend: MIR (few seconds) >> Sonication (minutes) > Grinding (min) >> thermal (several hrs).
基金the Chinese Postdoctoral Science Foundation for financial support(No.2004036602)
文摘Formamidine derivatives could be used as the building blocks for substituted heterocyclic compounds with various biological activities. N＇-Aryl-N,N-dimethylformamidinium chlorides have been synthesized in high yields by reaction of aromatic primary amines with Vilsmeier-Haack reagent at room temperature. The structures of all the new compounds were identified by ESI-MS, IR and NMR spectra. The steric structures of some of these compounds were clarified by X-ray single crystal analysis.
