12results about "Preparation by hydrogenolysis" patented technology

The invention relates to the technical field of organic synthesis, in particular to a preparation method of cyclopropyl formaldehyde, which comprises the following steps: by taking methyl cyclopropyl formate as a raw material, red aluminum as a reducing agent and toluene as a solvent, carrying out heat preservation reaction under the protection of nitrogen and controlling the reaction temperature to be not more than-78 DEG C; after the reaction is finished, firstly carrying out quenching reaction by using absolute ethyl alcohol, then adding a saturated ammonium chloride solution for further quenching reaction, then adjusting the pH value to be acidic, layering, collecting a water phase, extracting, combining the collected organic phase, drying, filtering, and then carrying out distillation treatment on the material liquid, so as to obtain the product. And rectifying the material liquid without the extracting agent to obtain a cyclopropyl formaldehyde product. The process method can reduce the cost, is suitable for industrial production, and greatly improves the yield and purity of the cyclopropyl formaldehyde product.

Disclosed are a fluorenylaminoketone photoinitiator, a preparation method thereof, and a UV photocurable composition containing same. The photoinitiator comprises a compound having a structure as shown in general formula (I) or a derivative compound thereof. The fluorenylaminoketone photoinitiator provided in the present invention may effectively improve the solubility of traditional photoinitiators and reduce the use of micromolecular active diluents, and also has high sensitivity and good effect of deep-layer curing. It has very good promotion effect on popularization and application of photocurable compositions, particularly colored ink systems, in the field of photocuring. The UV photocurable composition containing a fluorenylaminoketone photoinitiator of the present invention has advantages of high sensitivity, no residue after development, good pattern integrity, and no or little odor of coating layers after curing, as well as excellent yellowing resistance.

A method of preparing a triterpenoid compound of formula (I):including a step of converting a compound of formula (II) into the compound of formula (I),wherein R1 and R2 independently represent hydrogen or a protecting group selected from the group consisting of C1-C8 alkyl, allyl, C2-C8 alkenyl, C2-C8 alkynyl, (C6-C12)aryl(C1-C8)alkyl, tri(C1-C8)alkylsilyl, di(C1-C8)alkyl(C6-C12)arylsilyl, di(C6-C12)aryl(C1-C8)alkylsilyl ,tri(C6-C12)arylsilyl, —C(O)R7, and —C(O)OR8, and each of which is substituted with from 0 to 4 substituents independently selected from the group consisting of hydroxy, cyano, halo, halo(C1-C6)alkyl, halo(C1-C6)alkyloxy, (C1-C6)alkylthio, C1-C6 alkyl, C2-C6 alkenyl, C2-C6 alkynyl, C3-C7 cycloalkyl and C1-C6 alkoxy, wherein R7 and R8 are independently C1-C8 alkyl or C6-C12 aryl.

Provided: A method for manufacturing bisphenol A capable of efficiently removing coloring components derived from polycarbonate resin and producing bisphenol A with good color tone. In the bisphenol A manufacturing method of the present invention, a crude solution A obtained by decomposing polycarbonate resin (PC) in step A and removing the solvent by distillation, and a portion of a mother liquor D obtained in step D of steps B to E (where bisphenol A (BPA) is manufactured by dehydration condensation of acetone and phenol), are used to obtain solution H1 or solution H2. Solution H1 or solution H2 is supplied to step B or step C. Solution H1 is a solution containing BPA obtained by decomposing BPA contained in crude solution A and mother liquor D into phenol and isopropenylphenol, and then recombinating the phenol and isopropenylphenol. Solution H2 is a solution containing phenol obtained by decomposing BPA contained in crude solution A and mother liquor D into phenol and acetone.

The present disclosure relates to a method for preparing a compound as an intermediate for synthesizing the drug posaconazole and the intermediate compounds prepared thereby. The method for preparing a compound of Formula I provided in the present disclosure comprises: firstly reacting 4-(2,4-difluorophenyl)pent-4-enoate or its reduction product 4-(2,4-difluorophenyl)pent-4-enal as a starting material with formaldehyde or paraformaldehyde in the presence of a chiral catalyst, and then subjecting the reaction product to a characteristic oxidation, an esterification, a halogenation and cyclization reaction, finally a hydrolysis and an acid treatment. The preparation method of the present disclosure has advantages such as mild reaction conditions, simple reaction process, and high overall yield and high purity of target products, and thus is suitable for industrial production.

This invention relates to the field of electrochemistry, specifically disclosing a method for the selective electrooxidation of polyhydroxy compounds. More specifically, it involves the selective electrooxidation of compound (Ⅰ) to obtain compound (Ⅱ). This invention reduces the large number of byproducts caused by the simultaneous oxidation of multiple pairs of hydroxyl groups in traditional oxidation methods. By selectively electrooxidizing to obtain compound (Ⅱ), and then reducing compound (Ⅱ) to obtain compound (Ⅲ), for example, selectively electrooxidizing hydroxycitronellol (3,7-dimethyl-1,7-octanediol, compound 1a) to obtain (7-hydroxy-3,7-dimethyloctanoic acid, compound 2b), and then reducing it with compound 1b to obtain compound 1c. Compound 1c is hydroxycitronellol (CAS: 107-75-5), which has a strong floral fragrance. By changing the number of carbon atoms in hydroxycitronellol without changing the functional groups, a series of small molecule compounds with different fragrances can be produced efficiently and with low pollution.

The invention belongs to the technical field of catalytic conversion of bulk chemicals, and particularly relates to a method for preparing acetaldehyde and co-producing ethanol from synthesis gas and a preparation method of a catalyst thereof. The method for preparing acetaldehyde and co-producing ethanol from synthesis gas provided by the invention comprises the following steps: (1) a first stage: under the action of a CuZnAl catalyst and a molecular sieve, carrying out hydrogenation on the synthesis gas to generate methanol, dehydrating the methanol to generate dimethyl ether, and carrying out carbonylation on the dimethyl ether to synthesize methyl acetate; and (2) a second stage: under the action of the Mn-based catalyst, hydrogenating methyl acetate to prepare acetaldehyde and co-produce ethanol. The catalyst adopted by the method is low in cost, simple in synthesis, high in acetaldehyde selectivity, simple in technological process, high in safety coefficient and less in three wastes.

A method for preparing a triterpenoid compound represented by formula (I), comprising the step of converting a compound of formula (II) into a compound of formula (I). JPEG2025511059000047.jpg7864 During the ceremony, R1 and R2 are independently hydrogen or a C1-C8 alkyl group, an aryl group, a C2-C8 alkenyl group, a C2-C8 alkynyl group, (C6-C 12 )Aryl(C1-C8)alkyl group, tri(C1-C8)alkylsilyl group, di(C1-C8)alkyl(C6-C 12 )arylsilyl group, di(C6-C 12 )aryl(C1-C8)alkylsilyl group, tri(C6-C 12 ) an arylsilyl group, -C(O)R7, and -C(O)OR8, each of which is substituted with 0 to 4 substituents independently selected from the group consisting of a hydroxy group, a cyano group, a halo, a halo(C1-C6)alkyl group, a halo(C1-C6)alkyloxy group, a (C1-C6)alkylthio group, a C1-C6 alkyl group, a C2-C6 alkenyl group, a C2-C6 alkynyl group, a C3-C7 cycloalkyl group, and a C1-C6 alkoxy group; R7 and R8 are independently a C1-C8 alkyl group or a C6-C 12 It is an aryl group.

The invention belongs to the technical field of organic synthesis, and particularly relates to a preparation method of octadecanedioic acid monobenzyl ester. The preparation method comprises the following steps: firstly, reacting dodecanedioic acid with dichloromethane and N, N-dimethylformamide, adding an acylation reagent, and performing vacuum concentration to obtain a compound 1; secondly, reacting the compound 1 with dimethylbenzene, palladium carbon and organic alkali in a hydrogen atmosphere to obtain a compound 2; then, benzyl acrylate reacts with the compound 2 in an acetic acid aqueous solution to obtain a compound 3; and finally, reacting the compound 3 with Lewis acid and a reducing agent in dichloromethane, performing filtration, pH adjustment, liquid separation and concentration to obtain an octadecanedioic acid monobenzyl ester crude product, and performing recrystallization to obtain a final product. According to the method, cheap dodecanedioic acid is adopted as a starting material, the reaction process is simpler, safer and more efficient, the production cost is greatly reduced, and commercial production is facilitated.

A method of preparing a triterpenoid compound of formula (I): formula (I), including a step of converting a compound of formula (II) into the compound of formula (I), formula (II) wherein R1 and R2 independently represent hydrogen or a protecting group selected from the group consisting of C1-C8 alkyl, allyl, C2-C8 alkenyl, C2-C8 alkynyl, (C6-C12)aryl(C1-C8)alkyl, tri(C1-C8)alkylsilyl, di(C1-C8)alkyl(C6-C12)arylsilyl, di(C6-C12)aryl(C1-C8)alkylsilyl,tri(C6-C12)arylsilyl, -C(O)R7, and -C(O)OR8, and each of which is substituted with from 0 to 4 substituents independently selected from the group consisting of hydroxy, cyano, halo, halo(C1-C6)alkyl, halo(C1-C6)alkyloxy, (C1-C6)alkylthio, C1-C6 alkyl, C2-C6 alkenyl, C2-C6 alkynyl, C3-C7 cycloalkyl and C1-C6 alkoxy, wherein R7 and R8 are independently C1-C8 alkyl or C6-C12 aryl.

A system and method for the production of formaldehyde from electrocatalytically generated formic acid can include using a highly energy efficient electro-catalytic conversion step for producing aqueous formic acid, combined with a thermocatalytic reaction step to produce formaldehyde.

The invention belongs to the technical field of organic chemical industry, and particularly relates to a method for preparing chlorotrifluoroethylene. The method for preparing trifluorochlor oethylene comprises the following steps: step 1, catalytic reduction: in the presence of a ruthenium-tin bimetallic catalyst, under a hydrogen atmosphere and a heating condition, trifluoroacetic acid is subjected to a reduction reaction, and a product containing trifluoroacetaldehyde is generated; step 2, chlorination reaction: under cooling and illumination conditions, chlorine is introduced into the product containing trifluoroacetaldehyde obtained in the step 1 for chlorination reaction, and 2, 2-dichloro-1, 1, 1-trifluoroethane is obtained; and step 3, catalytic elimination: under the condition of a solid base catalyst, heating to enable the 2, 2-dichloro-1, 1, 1-trifluoroethane obtained in the step 2 to be subjected to a dehydrochlorination reaction to generate chlorotrifluoroethylene. According to the method for preparing the chlorotrifluoroethylene, the trifluoroacetic acid is adopted as the raw material, the raw material is easy to obtain, the process route is efficient and clean, and the prepared chlorotrifluoroethylene is high in yield and purity.