94-58-6

In this work, ultrasound-assisted electrocatalytic hydrogenation (US-ECHSA) of safrole was carried out in water medium, using sacrificial anode of nickel. The ultrasonic irradiation was carried out at frequency of 20 kHz ± 500 Hz with a titanium cylindrical horn (MS 73 microtip; Ti-6AI-4V alloy; 3.0 mm diameter). The optimal conditions were analyzed by statistical experimental design (fractional factorial). The influence of the sonoelectrochemical reactor design was also investigated by using computational fluid dynamics as simulation tool. Among the five parameters studied: catalyst type, use of β-cyclodextrin as inverse phase transfer catalyst, sonoelectrochemical reactor design, ultrasound mode and the temperature of the solution, only the last three were significant. The hydrogenation product, dihydrosafrole, reached 94% yield, depending on the experimental conditions applied. Data of computational fluid dynamics showed that a wing shape tube added to the sonoelectrochemical reactor can work as a cooling apparatus, during the electrochemical process. The reactional solution temperature diminishes 14 °C when compared to the four-way-type reactor. Cooper cathode, absence of β-cyclodextrin, four-way-type reactor, ultrasound continuous mode (14 W) and absence of temperature control were the most effective reaction parameters for the safrole hydrogenation using US-ECHSA method. The proposed approach represents an important contribution for understanding the hydrodynamic behavior of sonoelectrochemical reactors designs and, consequently, for the reducing of the experimental costs inherent to the sonoelectrochemical process.

The present disclosure provides a process of preparation of compounds of Formula I comprising the step of : reacting an alkylenedioxybenzene compound of Formula II with an acyl halide of Formula III in presence of a solvent, wherein the step of reacting the alkylenedioxybenzene compound of Formula II with the acyl halide of Formula III is effected in presence of an amphoteric oxide and a Lewis acid so as to immediately quench the compound of formula H-X, formed during the course of the reaction, to substantially eliminate degradation of the compound of any of Formula I and II. The present disclosure also provides for process(es) for preparation of compound of Formula IVa, IVb and IVc.

A Negishi cross-coupling of alkylpyridinium salts and alkylzinc halides has been developed. This is the first example of alkyl-alkyl bond formation via cross-coupling of an alkyl amine derivative with an unactivated alkyl group, and allows both primary and secondary alkylpyridinium salts to react with primary alkylzinc halides with high functional group tolerance. When combined with formation of the pyridinium salts from primary amines, this method enables the noncanonical transformation of NH2 groups into a wide range of alkyl substituents with broad functional group tolerance.

The present disclosure generally relates to the method of preparation of compounds of Formula IV. An aspect of the present disclosure relates to a process for preparation of compound of Formula IV, said process comprising the step of reacting an alkylenedioxybenzene compound of Formula II with an acyl halide of Formula III in presence of a solvent, characterized in that the step of reacting the alkylenedioxybenzene compound of Formula II with the acyl halide of Formula III is effected in the presence of an amphoteric oxide so as to in-situ quench the compound of formula H-X formed during the course of the reaction, thereby substantially eliminating degradation of the compounds of Formula IV and Formula II.

A high-yielding and high-rate reduction method that operates with alkenes, alkynes, azides, nitriles, and nitroarenes was developed and optimized. The method makes use of sodium borohydride reduction of CoSO4 under release of hydrogen along with the formation of Co2B as a nanoparticle material. The produced Co2B activates the various functional groups for hydride reduction. The protocol was proven to operate with an assortment of functional groups to provide good to excellent yields. Furthermore, the reduction method was successfully adapted, implemented, and developed for a continuous flow approach using the multi-jet oscillating disk (MJOD) flow reactor platform at atmospheric pressure.

Well-characterized, ruthenium nanoparticle-intercalated montmorillonite clay was used as a catalyst in solvent-free alkene hydrogenation reactions and the corresponding products were obtained in good yields. The catalytic activity of ruthenium nanoparticle-intercalated montmorillonite clay was successfully tested with 16 different functionalized and non-functionalized alkenes. Apart from alkene reduction, the ruthenium nanoparticle-intercalated montmorillonite clay was also tested in Wittig-type reactions for obtaining dehydrobrittonin A, an important intermediate for the synthesis of brittonin A. Ruthenium nanoparticle-intercalated montmorillonite clay was found to be active in the synthesis of dehydrobrittonin A and brittonin A. The ability to recycle the catalyst nine times, together with low catalyst loading, high catalytic activity and catalytic selectivity were noteworthy advantages of the proposed protocol.

Hydrogen and deuterium gas were produced and directly applied in a two-chamber system. These gaseous reagents were generated by the simple reaction of metallic zinc with HCl in water for H2 and DCl in deuterated water for D2. The setup proved efficient in classical Pd-catalyzed reductions of ketones, alkynes, alkenes, etc. in near-quantitative yields. The method was extended to the synthesis and isotope labeling of quinoline and 1,2,3,4-tetrahydroquinoline derivatives. Finally, CX-546 and Olaparib underwent efficient Ir-catalyzed hydrogen isotope exchange reactions.

The optimum conditions for the electrocatalytic hydrogenation (ECH) of benzaldehyde in water, using a nickel sacrificial anode (SA) (referred to as ECH-SA) and β-cyclodextrin (β-CyD) as inverse phase transfer catalyst (IPTC) were determined. Four parameters were investigated: the morphology of the nickel deposited on the cathode matrix (Cu, Fe, Ni or Fe/Ni alloy (64:36)) during a pre-electrolysis, the size of the CyD cavity, the concentration of β-CyD, the supporting electrolyte concentration and the current density applied. The results showed that a Ni matrix together with ultrasound pre-electrolysis treatment allowed a nanostructured nickel deposit on the cathode surface. Under the best electrolysis conditions (2.8 mmol dm -3 of β-CyD, 1.0 mol dm-3 of NH4Cl and a current density of 330 mA dm-2), the yield of benzyl alcohol (99%) was 27% higher than that obtained under the same conditions but in the absence of β-CyD. Taking into account the hydrophobic character of the β-CyD, the best conditions of the ECH-SA method were applied to the hydrogenation of a variety of organic substrates. Excellent yields and current efficiencies were obtained with arylbenzaldehydes and acetophenone. ECH-SA of styrene gave moderate yield and current efficiency, and the hydrogenation of a terminal non-conjugated olefin (safrole) was not efficient.

A recyclable catalyst, Ni(0)-CMC-Na, composed of nickel colloids dispersed in a water soluble bioorganic polymer, sodium carboxymethylcellulose (CMC-Na), was synthesized by a simple procedure from readily available reagents. The catalyst thus obtained is stable and highly active in alkene hydrogenations.

The larvicidal activity of 18 phenylpropanoids, 1-18, including phenylpropenoate, phenylpropenal, phenylpropene, and their semisynthetic analogues, were evaluated against the tobacco armyworm, Spodoptera litura (FAB.), to identify promising structures with insecticidal activity. Amongst various phenylpropanoids, isosafrole, a phenylpropene, showed the best activity, with an LC50 value of 0.6 μg/leaf cm2, followed by its hydrogenated derivative dihydrosafrole (LC50=2.7 μg/leaf cm 2). The overall larvicidal activity of various phenylpropene derivatives was observed in the following order: isosafrole (6) >dihydrosafrole (16)>safrole (12)>anethole (4)>methyl eugenol (11)>eugenol (13)>β-asarone (8)>dihydroasarone (18)>dihydroanethole (15). Dihydrosafrole might be a promising compound, although presenting a lower larvicidal activity than isosafrole, because of its better stability and resistance to oxidative degradation (due to the removal of the extremely reactive olefinic bond) in comparison to isosafrole. Such structure-activity relationship studies promote the identification of lead structures from natural sources for the development of larvicidal products against S. litura and related insect pests.

Nickel nanoparticles have been found to effectively catalyse the hydrogen-transfer reduction of a variety of non-functionalised and functionalised olefins using 2-propanol as the hydrogen donor. The heterogeneous process has been shown to be highly chemoselective for certain substrates, with all the corresponding alkanes being obtained in high yields. A synthesis of the natural dihydrostilbene brittonin A?is also reported based on the use of nickel nanoparticles.

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Direct use of the relatively inexpensive reagent, RuCl3 × H2O, as a catalyst for the reductions of olefins in the presence of water is reported. The combination of cheap and readily available sodium borohydride and a catalytic amount of RuCl3 × H2O selectively reduces mono- and disubstituted olefins, whereas trisubstituted olefins, unless activated, and benzyl ethers remain inert.

The solid state structure, phosphine dissociation rates and catalytic activity of several Rh-N-heterocyclic carbene complexes were studied. Catalytic activity for the hydrogenation of β-methylstyrene was improved by up to two orders of magnitude upon the addition of copper chloride. The catalyst with the highest inherent activity was found to be [Rh(IMes)(P-p-FC6H 4)3], although the p-methoxy derivative benefited the most from the addition of CuCl, giving turnover numbers of over 400 h-1.

Despite the generally accepted belief that carbene-metal bonds are strong and do not dissociate, the reaction of Rh-N-heterocyclic carbene complexes with triphenylphosphine in dichloroethane was determined to take place via cleavage of the Rh-carbene bond. The products of this reaction are Wilkinson's catalyst and a bisimidazolium salt derived from reaction between dichloroethane and two equivalents of the carbene. The implications of this reaction for catalysis are significant since the carbene complex shows lower activity than Wilkinson's catalyst in hydrogenation reactions. In non-halogenated solvents, the catalyst shows higher stability, such that the rate of exchange with free phosphine could be measured, and was determined to be ca. 10 times slower than in Wilkinson's catalyst.

Allyl aryl ethers can be easily cleaved by the use of 10% Pd/C under mild and basic conditions. The present reaction would involve a SET process rather than a π-allyl-palladium complex. The scope and limitation of this new deprotective methodology is also described.

The present invention regards a three-step process for the synthesis of 5-(α-hydroxyalkyl) benzo[1,3]dioxols. The process comprises: (i) the reaction of pyrocatechin (1,2-dihydroxybenzene) with a dihalo or di-alkoxyalkane, with the formation of a benzo[1,3]dioxol derivative; (ii) 5-selective catalytic acylation of the benzo[1,3]dioxol, with formation of a 5-alkanoylbenzo[1,3]dioxol and its subsequent (iii) reduction to 5-(α-hydroxyalkyl) benzo[1,3]dioxol. Also described are new benzodioxols obtainable using the above-mentioned process. The process of the invention is industrially simple and has low environmental impact; it allows to obtain in high yields derivatives of considerable interest, in particular for the perfumery industry, and in the sector of insecticides.

A bidentate rhodium phosphine complex anchored onto a mesoporous molecular sieve was shown to be an active catalyst for the hydrogenation of alkenes, with the activity dependent on the method of grafting, and in general, exceeding that of related homogeneous catalysts.

Cross-substituted derivatives of piperonyl butoxide (PBO) and MB-599 (proposed common name: verbutin) were synthesized and investigated as carbofuran and permethrin synergists against housefly, Musca domestica L. The majority of PBO and MB-599 derivatives were significantly more potent synergists for carbofuran than for permethrin. PBO, the most important representative of this series was not the most potent synergist for carbofuran or for permethrin. Cleavage of the methylenedioxy ring of methylenedioxyphenyl (MDP) polyether compounds resulted in complete loss of synergistic activity with both insecticides, but it could be restored or even improved by incorporating an alkynyl ether moiety into the molecule. The improved synergistic activity was found to be closely associated with the 2-butynyloxymethyl side-chain, suggesting that this can be regarded as a characteristic synergophore group. MB-599, one of the most promising compounds bearing this group showed considerably higher activity with carbofuran (synergist ratio, SR=37.8) than with PBO (SR=6.4). There was no significant difference between synergistic activities of MB-599 (SR=4.6) and PBO (SR=4) for permethrin.

The following description refers to a new process for the synthesis of 5-alkylated benzo[1,3]dioxole, comprising the following steps in sequence: catalytic hydrogenation of 4-acylphenol; acylation; displacement catalysed by Lewis acids; treatment with an inorganic basic compound and hydrogen peroxide; reaction with alkyl dihalides or dialkoxyalkanes. The process described herein, which yields 5-alkylbenzo[1,3]dioxoles, is economic and can be easily scaled up to industrial size.

The following description refers to a new process for the synthesis of 5-alkylated benzo[1,3]dioxole, consisting in the following steps in sequence: catalytic hydrogenation of 4-acylphenol; acylation; displacement catalysed by Lewis acids; treatment with an inorganic basic compound and hydrogen peroxide; reaction with alkyl dihalides or dialkoxyalkanes. The process described herein, which yields 5-alkylbenzo[1,3]dioxoles, is economic and can be easily scaled up to industrial size.

A well-characterized primary rat hepatocyte culture system was used to examine induction patterns of cytochrome 450 gene expression by a series of 4-n-alkyl-methylenedioxybenzene (MDBs) derivatives. Hepatocytes were treated for 24, 48, or 72 hours with 0-500 microM of the MDB compounds, and total cellular RNA and protein from each treatment was evaluated by hybridization and immunochemical techniques. Exposure to MDB congeners possessing increasing 4-n-alkyl side-chain length (C0-C8) resulted in dose- and structure-dependent activation of CYP2B1, 2B2, 3A1, 1A1, and 1A2 gene expression. At equivalent 100 microM concentrations, the C6 and C8 MDB congeners were more effective than the prototypical inducer phenobarbital (PB) with respect to induction potency of CYP2B1, CYP2B2, and CYP3A1 gene expression. In contrast to PB, longer side-chain-substituted MDBs effectively induced CYP1A1 and CYP1A2 gene expression, in addition to the CYP2B and CYP3A genes. At equivalent molar concentrations, the catechol derivative of C6-MDB was ineffective in its ability to induce CYP gene expression, indicating the importance of the intact methylenedioxy bridge in the induction mechanism. Levels of MDB-inducible CYP2B1 and CYP2B2 mRNA were highly correlated with CYP2B1/2 apoprotein levels, ascertained by immunoblot analysis of cultured hepatocyte S9 fractions. Compared with results from previous in vivo analysis (12), the current data indicate that pharmacodynamic factors may influence MDB induction profiles and that differences in MDB effects on CYP gene expression result depending on distinct structure-activity relationships.

A reducing system, NaBH4-Cu2Cl2/MeOH, was developed for dehalogenation of aryl halides, conjugate reduction of α,β-unsaturated esters, and deuterium labeling in a chemo- and regioselective manner.These reactions proceeded without reduction of isolated olefins.The Cu2Cl2 is assumed to function as the catalyst which generates a transient species of copper hydride as an active reducing agent, on contact with NaBH4.Deuterium-labeling studies indicated that (i) the hydrogen which is transferred to the 4-position of methyl 4-iodobenzoate originates from MeOH and (ii) thehydrogens which were transferred to the α- and β-positions of the conjugated ester originate from MeOH and NaBH4, respectively.

Secondary and tertiary benzylic alcohols are reduced conveniently to the corresponding aryl alkanes by using Me3SiCl-NaI-CH3CN reagent in hexane.The reaction was successfully applied to a short step synthesis of (+/-)-ar-turmerone.

Cation radicals derived from the title compounds by oxidation with thallium tristrifluoroacetate have been characterized.The structures assigned to these radicals suggest that initial oxidation occures at the phenethyl ring in the compounds examined.Oxidation of homolaudanosine in this way gave the expected homoaporphine.

Steganacin and Steganangin, dibenzocyclooctadiene lignan lactones, have been reported to possess antileukemic activity. This invention describes the first total synthesis of these compounds and other relevant intermediates.

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