4results about How to "Short reaction steps" patented technology

This invention relates to the field of compound synthesis technology, specifically disclosing a method for preparing 8-chloronaphtho[1,2-b]benzofuran. The preparation method includes the following steps: mixing compound 1 with a solvent, then adding sodium hydroxide and sodium chloride, followed by dropwise addition of an aqueous solution of sodium hypochlorite, stirring the reaction mixture to obtain the target compound 8-chloronaphtho[1,2-b]benzofuran. The preparation method provided by this invention is low-cost and has a high yield.

The invention discloses a preparation method of p-phenylene-bis-benzene trimellitate dianhydride, and relates to the technical field of preparation of organic compounds. The preparation method provided by the invention comprises the following steps: mixing chlorinated trimellitic anhydride, hydroquinone and a catalyst, and reacting to obtain a p-phenylene-bis-benzene trimellitate dianhydride crude product; and recrystallizing the p-phenylene-bis (trimellitate) dianhydride crude product, mixing with acetic anhydride, and reacting to obtain the p-phenylene-bis (trimellitate) dianhydride, the catalyst is prepared from at least one of pyridine, triethylamine, N, N-diisopropylethylamine, diethylamine and dimethylamine. The preparation method provided by the invention improves the purity and whiteness of p-phenylene-bis (trimellitate) dianhydride, and has the advantages of short reaction steps, mild conditions, simple post-treatment, high yield, simple refining steps, high product purity and the like.

The application relates to the technical field of compound synthesis, and particularly discloses a preparation method of 2-bromofluorenone. According to the method, 4-bromo-2'-iodo-biphenyl is reacted with carbon dioxide under the action of a strong base to generate 2-bromofluorenone in one step, the reaction step is short, the production cost is greatly reduced, the reaction condition is mild, the process operation is simple, the post-treatment of the reaction is simple, the product with high purity can be easily obtained, and the method is suitable for process amplification production.

The application discloses a method for preparing heliotropin, which comprises the following steps: taking piperine as a raw material, and performing chloromethylation and oxidation reaction to obtain heliotropin, wherein water is used as a solvent in the oxidation step, and oxygen-containing gas is used as an oxidant; the reaction is performed under normal pressure, the conditions are mild, the three wastes are less, the selectivity is good, and the yield is high, so the method is a better industrial production method.