68367-32-8

Upstream product

• 106-44-5 p-cresol 
• 334-48-5 1-decanoic acid 
• 79674-07-0 Bis disulfide 

Downstream Products

• 76115-96-3 1-(2-hydroxy-5-methylphenyl)decan-1-one 
• 100780-66-3 2-Decyl-4-methyl-phenol 

Relevant academic research and scientific papers

Diacyl Disulfide: A Reagent for Chemoselective Acylation of Phenols Enabled by 4-(N,N-Dimethylamino)pyridine Catalysis

A general and excellent acylation reagent, diacyl disulfide, was uncovered for efficient ester formation enabled by DMAP (4-(N,N-dimethylamino)pyridine) catalysis. This protocol offered a promising synthetic platform on site-selective acylation of phenolic and primary aliphatic hydroxyl groups, which greatly expanded the realm of protecting group chemistry. The importance of the reagent was also reflected by its excellent moisture tolerance, high efficiency, and potential in synthetic chemistry and biologically meaningful natural product modification.

The active site accessibility aspect of montmorillonite for ketone yield in ester rearrangement

The removal of Al from the octahedral layer of montmorillonite by organic acid treatment results in increased microporosity generating a material with different surface features from the virgin clay. The micropores thus generated are found to be responsible for ester to ketone transformation. Various parameters of the newly generated pores such as the pore diameter, pore structure, pore volumes and acidity by pyridine-FTIR were evaluated with respect to ester to ketone formation. The best correlation was found between the volume accessibility factors (VAF) and the ketone yield. The VAF reflects the extent of volume space available around the acid site for the reactant to orient in a specific way for the transformation to occur within the pore to form a specific product. This acid site accessibility aspect was further verified by extending to micropores with large VAF generated by treatment with phenoldisulfonic acid (PDSA).

Active and deactive modes of modified montmorillonite in p-cresol acylation

para-Toluene sulphonic acid (p-TSA)-treated montmorillonite clay used as heterogeneous catalyst in acylation of para-cresol (PC) with aliphatic carboxylic acids. Reactions were studied under microwave and conventional modes of heating and reaction conditions were optimized by varying mole ratio, temperature, amount of catalyst and reaction time. Under optimized conditions the reaction was carried out involving p-cresol and decanoic acid. The reaction involved two steps, O-acylation involving ester formation followed by the Fries rearrangement involving C-acylation resulting in ketone product. Microwave heating mode showed higher conversion and the catalytic activity almost retained in repeated use. On the other hand the catalytic activity dropped by more than 50% in the case of conventional heating indicating rapid deactivation. A change in the color of the used catalyst was more intense in the case of conventional than in the microwave heating. Used catalysts were characterized for surface area and pore volume by BET technique, acidity by FTIR spectroscopy and amount of coke by TGA. Further investigations on the catalyst used in conventional heating revealed that the deactivation occurred during the O-acylation and not in the subsequent Fries rearrangement. However, the catalyst in the microwave irradiated reaction, exhibited a retarded rate of formation of coke precursors on the surface during O-acylation, thus preventing any decrease in catalytic activity. Present study indicates that the technique chosen for heating the reaction medium plays an important role in suppressing deactivation.

Microwave-induced deactivation-free catalytic activity of BEA zeolite in acylation reactions

Solventless liquid-phase acylation of p-cresol with different aliphatic carboxylic acids like acetic, propionic, butyric, hexanoic, octanoic, and decanoic acids was investigated over BEA zeolite under conventional as well as microwave heating. An unanticipated huge difference in activity was observed between two modes of heating. Under conventional heating, conversion of all the acids was less than 20%, while under microwave heating, the conversion was in the range of 50-80%. Ester formed through O-acylation and ortho-hydroxyketone formed through Fries rearrangement of the ester were the only products. Conversion of carboxylic acid increased with chain length up to hexanoic acid and then it showed a decrease in the trend. With all the acids, O-acylation occurred rapidly followed by slow conversion to ortho-hydroxyketone. The ketone/ester ratio increased with catalyst amount, temperature, and reaction time. Used catalyst samples were characterized by TGA, XRD, and IR studies to understand lower activity and deactivation behavior under conventional heating. The results showed absence of coke precursor/coke on the catalyst used in microwave-irradiated reactions in contrast to catalyst used in conventionally heated ones. Higher yield in the case of microwave-assisted reactions is attributed to the prevention of coke precursor/coke on the active sites by microwaves.

Direct esterification of carboxylic acids with p-cresol catalysed by acid activated Indian bentonite

Acid activated Indian bentonite (AAIB) catalyst is used for the first time to esterify various carboxylic acids with p-cresol in average to excellent yields. Optimisation studies have been carried out for p-cresyl stearate synthesis. The catalyst is recoverable and recyclable.

Lipase catalyzed esterification of cresols

Esters of m- and p-cresols with organic acids having carbon chain lengths C2-C18 have been prepared by using lipases from porcine pancreas and Rhizomucor miehei. Gram level conversions are carried out under non-solvent conditions in case of shake flask experiments and continuous removal of water at bench-scale levels. Addition of 0.1 mL of 0.1M phosphate buffer at pH 7.0 to the reaction mixture shows better conversions. Optimization studies have been carried out for p-cresyl laurate synthesis using Rhizomucor miehei lipase which show a maximum conversion of 74.4 %. Better conversions are obtained with larger amounts of enzyme. Porcine pancreas lipase catalyzed synthesis of m- and p-cresyl esters show that under identical reaction conditions acids with lower carbon chain lengths (C2-C4) give ester yields above 30%, while those with longer carbon chain lengths give ester yields 30%.