The great piperonyl butoxide to piperonal debate. High yielding Chinese patent using hexamine and polyphosphoric or Preferably, the catalyst is polyphosphoric but 1 or more of phosphoric acid, acetic anhydride or polyphosphoric acid is acceptable
Ok it's first of all Chinese. And either they lie or they need lab equipment mostly not suitable for the clandestine chemist or the catalyst or reagents are unobtanium like .. yellow cake and alike either impossible or crazy watched But I don't see the breakdown of the synethsis via Lewis structures on the patent or the reaction schemes. Can anyone help or understand or is this bullshit? I have no idea how we missed this before?
The parents are based on everything we have discussed prior.
Chinese patent Aiming at the problems in the prior art, the invention provides a novel method for synthesizing piperonal, which is relatively low in price and mild in reaction conditions
the method comprises the following steps of (1) reacting piperonyl, a catalyst and urotropine in an alcohol solvent at 50-120 ℃ for 1-10 hours;
the catalyst is polyphosphoric acid;
the alcohol solvent is one or more of methanol, ethanol, propanol, isopropanol, n-butanol, isobutanol, n-pentanol or isoamylol;
the mass ratio of the catalyst to the piperonyl butoxide is 6-20: 1;
the molar ratio of the piperonyl butoxide to the urotropine is 1: 0.3-5.
2. The method according to claim 1, wherein the reaction temperature is 70 to 100 ℃.
3. The process according to claim 1, wherein the alcoholic solvent is ethanol.
4. The method according to claim 1, wherein the reaction time is 3 to 5 hours.
5. The method according to claim 1, wherein the preparation method further comprises a step of separating a product by extraction or distillation after the reaction is completed.
6. The method according to claim 1, wherein the mass ratio of the catalyst to the piperonyl butoxide is 10-15: 1.
7. The method as claimed in claim 1, wherein the molar ratio of piperonyl butoxide to urotropin is 1: 0.7-1.5.
The reaction formula of the method is as follows:
the invention has the beneficial effects that:
the invention adopts the piperonyl to prepare the piperonal by taking the piperonyl as the raw material, only needs one-step reaction, simplifies the working procedures, has higher yield, relatively lower three-waste discharge amount, is easy to treat waste water and is easy to realize industrial production.
Adding 680g polyphosphoric acid into a 2000ml three-neck flask, adding 120ml ethanol under stirring, heating to 55 ℃, slowly dropwise adding 50g (0.41mol) of piperonyl butoxide, dropwise adding 60g (0.43mol) of urotropine after 0.5 hour, starting to heat to 90-100 ℃ after the addition is finished, preserving heat for 3 hours, sampling for liquid phase analysis, cooling to 60-70 ℃, adding 700ml water, stirring for 3 hours, adding 650ml ethyl acetate for two times of extraction, combining organic phases, adding 400ml saturated salt water for washing, separating out the organic phase, adding 40g anhydrous sodium sulfate, drying for 1 hour, filtering, concentrating ethyl acetate at 40 ℃ of filtrate, and distilling the residual oil under reduced pressure by an oil pump to obtain 43g piperonal with the purity of 99%. 1H-NMR(300MHZ)：(δ6.08(s，2H)；δ6.95(d，1H)；δ7.34(s，1H)；δ7.43(d，1H)；δ9.82(s，1H)。
Adding 350g of polyphosphoric acid into a 1000ml three-neck flask, adding 100ml of ethanol under stirring, heating to 55 ℃, slowly adding 50g of piperonyl butoxide dropwise, completing dripping after 0.5 hour, adding 60g of urotropine, completing feeding, starting to raise the temperature to 70 ℃, keeping the temperature for 5 hours, sampling, analyzing a liquid phase, cooling to 60-70 ℃, adding 300ml of water, stirring for 3 hours, adding ethyl acetate for twice extraction, 400ml each time, combining organic phases, adding 300ml of saturated saline solution for washing, separating out the organic phases, adding 30g of anhydrous sodium sulfate, drying for 1 hour, filtering, concentrating ethyl acetate at 40 ℃ of filtrate, and distilling the residual oil under reduced pressure by an oil pump to obtain 40g of piperonal with the purity of 99%.
Adding 500g of phosphoric acid catalyst into a 2000ml three-neck flask, adding 150ml of methanol under stirring, heating to 55 ℃, slowly adding 50g of piperonyl, dropping after 0.5 hour, adding 82g (0.59mol) of urotropine, starting to heat to 80 ℃, preserving heat for 7 hours, sampling, carrying out liquid phase analysis, cooling to 60-70 ℃, adding 700ml of water, stirring for 3 hours, adding ethyl acetate for two-time extraction, combining organic phases, adding saturated salt solution for washing, separating out the organic phase, adding 40g of anhydrous sodium sulfate for drying, filtering, concentrating ethyl acetate at 40 ℃ of filtrate, and carrying out reduced pressure distillation on residual oil pump to obtain 31g of piperonal with the purity of 97%.
Based on
C07D317/54 Radicals substituted by oxygen atoms
The present invention relates to a method capable of using p-methyl phenol as raw material and adopting the processes of esterification, dislocation, oxidation, ring-closing reaction, chlorination and hydrolysis to obtain heliotropin.
The object of the present invention is to provide a kind of with 3; 4-methylene radical dioxy benzyl chlorine is the chemical synthesis process that piperonal prepared by raw material;
https://patents.google.com/patent/CN105503814A/en
Non-Patent Citations
Synthesis by Formylation of Arene—Hydrogen Bonds forming acid derivatives DOI: 10.1055/b-003-121811
And
Research on the synthesis method of 5-nitrosalicylaldehyde; Bu Xinyu; China Excellent Doctoral and Masters Dissertations Full-text Database (Master) Engineering Science and Technology Series I; 20041215; Section 2.2.2.2.1, Section 3.2.3
5-硝基水杨醛合成方法的研究;卜鑫宇;《中国优秀博硕士学位论文全文数据库（硕士）工程科技I辑》;20041215;第2.2.2.2.1节，第3.2.3节
And
The present invention provides a kind of preparation method of piperonal, including：By piperonyl cyclonene, catalyst and methenamine in alcoholic solvent, reacts 1 ~ 10h in 50 ~ 120 DEG C and obtain piperonal.Integrated artistic only needs single step reaction, technique to simplify, and yield is higher, and three wastes discharge amount is relatively low, and waste water is also easily processed, industrialized production easy to implement.
https://patents.google.com/patent/CN108752310A/en
By piperonyl cyclonene, catalyst and methenamine in alcoholic solvent, 1 ~ 10h is reacted in 50 ~ 120 DEG C；Preferably reaction temperature is 70~100℃。 2. according to the method described in claim 1, it is characterized in that, the catalyst is in phosphoric acid, aceticanhydride or polyphosphoric acids It is one or more of. 3. according to the method described in claim 2, it is characterized in that, the catalyst is polyphosphoric acids. 4. according to the method described in claim 1, it is characterized in that, the alcoholic solvent is methanol, ethyl alcohol, propyl alcohol, isopropanol, just One or more of butanol, isobutanol, n-amyl alcohol or isoamyl alcohol. 5. according to the method described in claim 4, it is characterized in that, the alcoholic solvent is ethyl alcohol. 6. according to the method described in claim 1, it is characterized in that, the reaction time is 3 ~ 5h. 7. according to the method described in claim 1, it is characterized in that, the preparation method further includes extracting or steaming after reaction The step of fraction is from product. 8. according to the method described in claim 1, it is characterized in that, the mass ratio of the catalyst and piperonyl cyclonene is 6 ~ 20:1, It is preferred that 10 ~ 15:1. 9. according to the method described in claim 1, it is characterized in that, the molar ratio of the piperonyl cyclonene and methenamine is 1:0.3~ 5, preferably 1:0.7~1.5.
Some more digging
CN103833722B
https://patents.google.com/patent/CN103833722B/en
Classifications C07D317/50
Methylenedioxybenzenes or hydrogenated methylenedioxybenzenes, unsubstituted on the hetero ring with only hydrogen atoms, hydrocarbon or substituted hydrocarbon radicals, directly attached to atoms of the carbocyclic ring
And the method for chemosynthesis prepares the document of safrole and few, NaofumiTsukada reports (Synlett, (10), 1431-1434; 2003) be raw material by the p-toluenesulfonic esters of piperonyl cyclonene and vinyl carbinol, adopt rare metal complex compound to be catalyst preparing safrole.The rarer costliness of catalyzer that this method uses and being difficult to obtain, and its productive rate is not high yet. The people such as Lin Bin, Yang Xi report (Guangdong chemical industry, 30 (2), 6-7; 2003) be raw material with piperonyl cyclonene, first its bromo become corresponding bromide, then make Grignard reagent, then prepare safrole with allyl bromine reaction.Although the method raw material is easy to get, reaction conditions is also relatively gentle, but need piperonyl cyclonene to become corresponding Grignard reagent, obtained by grignard reaction again, a large amount of autoimmunity syndrome by products is so inevitably had to produce, bring difficulty to separation, waste a large amount of raw materials, and grignard reaction is also stricter to reagent requirement. The people such as StefanoProtti report (Organic & BiomolecularChemistry, 3 (15), 2868-2871; 2005) be raw material with chloro piperonyl cyclonene and allyltrimethylsilane alkane, under cesium carbonate and trifluoro sulfonation, prepare safrole.The raw material allyltrimethylsilane alkane costliness that the method adopts on the one hand is difficult to obtain, and the singularity of this reaction process, makes its industrialization not easily realize on the other hand. Therefore, the method finding an effective full chemosynthesis sassafras wood oil rope becomes the study hotspot of various countries' chemist. Summary of the invention
