Measurements and modeling for the density of 2-methoxy-2,4,4-trimethylpentane,HE for (methanol + 2-methoxy-2,4,4-trimethylpentane), LLE for (water + 2-methoxy-2,4,4-trimethylpentane) and LLE for (water + methanol + 2-methoxy-2,4,4-trimethylpentane)

Oxygenates are used in gasoline to increase the octane number and reduce carbon monoxide emission. 2-methoxy-2,4,4-trimethylpentane (TOME) is a tertiary ether which can potentially be used in addition with current oxygenates. This compound can be produced by etherification of diisobutylene with methanol. During the etherification, water is formed due to the dehydration of methanol. The appearance of water can cause (liquid + liquid) phase split in the production process. In this work, several physical properties of systems containing water, methanol and TOME are studied for the first time. The liquid density of 2-methoxy-2,4,4-trimethylpentane is presented from T = (298.15 to 408.16) K. Excess enthalpies are reported for the binary system of (methanol + 2-methoxy-2,4,4-trimethylpentane) at (T = 298.15 K). The (liquid + liquid) equilibrium (LLE) for (water + 2-methoxy-2,4,4-trimethylpentane) from T = (283.15 to 318.15) K is determined. The LLE is also reported for the ternary system of (water + methanol + 2-methoxy-2,4,4-trimethylpentane) at T = (283.15 and 298.15) K. The UNIQUAC parameters were regressed to model VLE, excess enthalpy and LLE for the binary and ternary data with one set of parameters.     

Stereostructure of 2-ethynyl-substituted 2,4,4-trimethyl-1,3-dioxanes

It has been shown by PMR spectrometry and x-ray structure analysis that the six-membered 1,3-dioxane ring of 2-ethynyl-substituted 2,4,4-trimethyl-1,3-dioxanes, either in solution or in the solid state, exists in a nearly ideal chair conformation with an axial position of the ethynyl substituent. Kuban State Technological University, Krasnodar 350072, Russia. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 2, pp. 163–169, February, 1998.     

2,4,4‐Tri­methyl‐2‐phenyl‐3‐pentanone oxime

The title compound, C₁₄H₂₁NO, has two mol­ecules in the asymmetric unit. Each mol­ecule forms hydrogen‐bonded dimers about inversion centers via O—H?N hydrogen bonds between oxime groups. The N—O distances in the oxime groups are 1.4160 (15) and 1.4131 (14) Å.     

Zur Synthese des 2-Chlor-2,4,4-Trifluor-1,3-Dithietans und seiner S-Oxide

The series of 2-chloro-2,4,4,-trifluoro-1,3-dithietane-S-oxides could be synthesized, e.g. the 1-oxide 3, 1,1,-dioxide 4, 1,3-dioxide 6, 1,1,3-trioxide 7 and 1,1,3,3,-tetroxide 5. From 7 the sulfone HF₂C-SO₂-CClFH (8) could be obtained by hydrolysis in methanol. All compounds were identified by MS-, NMR-, IR-spectra and elementary analyses. The sulfines F₂C=SO and ClFC=SO were detected in an argon matrix after vacuum pyrolysis of 6.     

沸石催化的2,4,4-三甲基-1-戊烯的酰化反应

通过HY沸石与某些传统催化剂的比较，发现HY在2，4，4-三甲基-1-戊烯与乙酸酐的酰化反应中比那些传统催化剂更有效．用HY沸石作催化剂，室温下通过2，4，4-三甲基-1-戊烯与乙酸酐的酰化反应，合成了三种异构体，即4-（2，2-二甲基丙基）-4-戊烯-2-酮、（E）-4，6，6-三甲基-4-庚烯-2-酮和（Z）-4，6，6-三甲基-4-庚烯-2-酮．考察了HY沸石的用量对该酰化反应的影响．当2，4，4-三甲基-1-戊烯／乙酸酐／HY沸石=1mmol／10mmol／0．250g，反应温度25℃、反应时间2h时，生成的三种异构体产率之和为72％，HY沸石对于该反应具有极好的选择性和优良的活性稳定性，不同阳离子交换的Y沸石也用于催化2，4，4-三甲基-1-戊烯的酰化反应。     

Measurements and modeling of LLE and HE for (methanol + 2,4,4-trimethyl-1-pentene), and LLE for (water + methanol + 2,4,4-trimethyl-1-pentene)

Excess enthalpy (H^E) for the binary system of (methanol + 2,4,4-trimethyl-1-pentene) (TMP-1) is reported at T = 298.15 K and 101 kPa. (Liquid + liquid) equilibrium (LLE) for the same system is measured at atmospheric pressure (101 kPa). LLE for ternary system of (water + methanol + 2,4,4-trimethyl-1-pentene) is measured at T = (283 and 298) K.The parameters of Non-Random Two-Liquid (NRTL) model were regressed for the system of (methanol + TMP-1) using H^E and LLE from this work combined with isobaric (101 kPa) and isothermal (T = 331 K) VLE data from literature. The NRTL parameters for the binary system of (water + TMP-1) were fitted to a binary LLE data set from literature. NRTL parameters for the binary system of (water + methanol) were taken from ASPEN PLUS. The LLE for the ternary system was modeled by the three binary NRTL interaction parameters systems. The binary and ternary models were compared against the measured data.     

First synthesis of 2‐(2,4,4‐trimethyl‐3,4‐dihydro‐2H‐benzo[h]chromen‐2‐yl)‐1‐naphthol and 3‐(2,4,4‐trimethyl‐3,4‐dihydro‐2H‐benzo[g]chromen‐2‐yl)‐2‐naphthol from 1‐ and 2‐naphthol derivatives

Two new structurally isomeric, 2‐(2,4,4‐trimethyl‐3,4‐dihydro‐2H‐benzo[h]chromen‐2‐yl)‐1‐naphthol ( 1 ) and 3‐(2,4,4‐trimethyl‐3,4‐dihydro‐2H‐benzo[g]chromen‐2‐yl)‐2‐naphthol ( 3 ) have been synthesized from 2‐acetyl‐1‐naphthol and ethyl‐3‐hydroxy‐2‐naphthoate, respectively, involving Grignard reaction, dehydration of the corresponding tertiary alcohols, and hetero Diels–Alder dimerization. The two benzochromenes ( 1 and 3 ) have been fully characterized by IR, NMR, and HRESIMS data. Their structures are further supported by crystallography of their corresponding acetates ( 2 and 4 ). J. Heterocyclic Chem., (2011).     

Kinetics studies of 5-methyl-2-hexanol, 2,2-dimethyl-3-hexanol,and 2,4,4-trimethyl-1-pentanol with chlorine atoms: Photooxidation mechanism of 2,4,4-trimethyl-1-pentanol

The rate constants for the reaction between chlorine atoms and either 5-methyl-2-hexanol, 2,2-dimethyl-3-hexanol, or 2,4,4-trimethyl-1-pentanol at 298 K were determined using the relative method with 2-butanol and 1-pentanol as reference compounds. The values obtained for 5-methyl-2-hexanol, 2,2-dimethyl-3-hexanol, and 2,4,4-trimethyl-1-pentanol (k × 10¹⁰ cm³ molec⁻¹ s⁻¹) were, respectively, (2.64 ± 0.5), (2.72 ± 0.5), and (2.50 ± 0.4), in agreement with the values of the rate constants reported in bibliography for similar alcohols and the values estimated by structure activity relationship methods. The photooxidation products of 2,4,4-trimethyl-1-pentanol initiated by chlorine atoms were identified (formaldehyde, 2-propanone, 2,2-dimethyl propanal, 4,4,-dimethyl-2-pentanone, and 3,3-dimethylbutanal), and the reaction mechanism was determined.     

Effectiveness of the Natural Antioxidant 2,4,4′-Trihydroxychalcone on the Oxidation of Sunflower Oil during Storage

This study aimed to investigate the effectiveness of 2,4,4′-trihydroxychalcone as a natural antioxidant on the oxidation of sunflower oil during an 88-day storage period and to compare its strength with the synthetic antioxidant butylated hydroxytoluene (BHT). Seven groups of the sunflower oil samples were prepared: pure oil (control), oil treated with different concentrations (100, 500, and 1000 ppm) of 2,4,4′-trihydroxychalcone, and oil treated with different concentrations (100, 500, and 1000 ppm) of BHT. Specific parameters, namely, the peroxide value (PV), acid value (AV), p-anisidine value (p-AnV), thiobarbituric acid reactive substance (TBARS) value and total oxidation (TOTOX) value were used to assess the extent of the deterioration of the oil by estimating the primary and secondary oxidation products. The results showed that 2,4,4′-trihydroxychalcone effectively decreased the production of the primary and secondary oxidation products of sunflower oil during storage, as indicated by reductions in the PVs, AVs, p-AnVs, TBARS values and TOTOX values of the sunflower oil. When compared to BHT, 2,4,4′-trihydroxychalcone showed either a similar or stronger effect in inhibiting the primary and secondary oxidation products. These findings suggest that, 2,4,4′-trihydroxychalcone is a suitable natural alternative to synthetic antioxidants to improve the oxidative stability of sunflower oil.