Month: December 2022

Koutek, Bohumir published the artcileGas chromatographic determination of vapor pressures of pheromone-like acetates, Application In Synthesis of 16974-11-1, the publication is Journal of Chromatography (1992), 626(2), 215-21, database is CAplus.

The vapor pressures of nineteen Z and E monounsaturated C₁₀-C₁₆ even-carbon acetates were determined using a method based on gas chromatog. (GC) retention data. Exptl. measurements were carried out at six temperatures in the range 90-140° on a 2-m HP-1 capillary column by utilizing n-C₁₈ and n-C₂₀ hydrocarbons as vapor pressure reference compounds Corrections for the systematic errors were made by relating the exptl. determined vapor pressures P_GC to the literature values P_L through a linear regression relationship. Over a narrow temperature range of 25-45°, the GC-measured vapor pressures were found to satisfy the Clausius-Clapeyron equation. Also, for structurally similar subseries of acetates, e.g., for ω – 3 or ω – 5 unsaturated derivatives, the vapor pressures were shown to have a simple dependence on the number of carbon atoms per mol. The vapor pressures at 25° ranged from 2.633 Pa for (Z)-5-decenyl acetate to 0.005 Pa for (E)-13-hexadecenyl acetate.

Journal of Chromatography published new progress about 16974-11-1. 16974-11-1 belongs to esters-buliding-blocks, auxiliary class Aliphatic Chain, name is (Z)-Dodec-9-en-1-yl acetate, and the molecular formula is C14H26O2, Application In Synthesis of 16974-11-1.

Referemce:
https://en.wikipedia.org/wiki/Ester,
Ester – an overview | ScienceDirect Topics

Konishi, Hideyuki published the artcilePractical synthesis of axially chiral dicarboxylates via Pd-catalyzed external-CO-free carbonylation, COA of Formula: C22H12F6O6S2, the publication is Chemical & Pharmaceutical Bulletin (2016), 64(10), 1438-1441, database is CAplus and MEDLINE.

A safe and practical synthetic method for preparing axially chiral di-Ph dicarboxylates using Pd-catalyzed external-CO-free carbonylation with Ph formate as a CO surrogate was developed. Optimized conditions consisted of axially chiral [1,1′-binaphthalene]-2,2′-diyl ditriflate and its congeners, each easily prepared from com. available enantiomerically pure diols, Pd(OAc)₂, 1,3-bis(diphenylphosphino)propane, ethyldiisopropylamine, and no solvent. To demonstrate the potential utility of these products, this method was conducted on gram-scale and the Ph ester products were converted to other useful compounds, and both processes were carried out without difficulty.

Chemical & Pharmaceutical Bulletin published new progress about 126613-06-7. 126613-06-7 belongs to esters-buliding-blocks, auxiliary class Chiral Diphenols, name is (R)-[1,1′-Binaphthalene]-2,2′-diyl bis(trifluoromethanesulfonate), and the molecular formula is C22H12F6O6S2, COA of Formula: C22H12F6O6S2.

Referemce:
https://en.wikipedia.org/wiki/Ester,
Ester – an overview | ScienceDirect Topics

Kickova, Anna published the artcileSynthesis and properties of macrocyclic diazene switch with binaphthalene unit attached via acrylamide linkers, Recommanded Product: (R)-[1,1′-Binaphthalene]-2,2′-diyl bis(trifluoromethanesulfonate), the publication is Chemical Papers (2013), 67(1), 101-109, database is CAplus.

2,2′-Diiodo-1,1′-binaphthalene undergoes a tandem Heck reaction with Me acrylate to afford 2-(7H-dibenzo[c,g]fluoren-7-ylidene)acetic acid Me ester. As a consequence, a target macrocyclic diazene with binaphthalene unit attached by an acrylamide linker was prepared by a stepwise building of acrylamide at a binaphthalene moiety, including the Doebner modification of the Knoevenagel condensation, and completed by oxidative macrocyclization of aniline end-groups. The synthesis of the target compounds was achieved using (R)-2,2′-diiodo-1,1′-binaphthalene as a starting material. Despite being an equimolar mixture of monomer and dimer, it exhibited remarkable changes in CD spectra ldue to reversible (E/Z) isomerization of N=N diazene bonds upon irradiation at 365/465 nm. The title compounds thus formed included a macrocyclic azole propenamide binaphthalene (I) (monomer) and a corresponding dimer. Although the dimer isomerizes from (E) to (Z) isomer 7.4 times faster than the monomer I the latter’s contribution to the change in ellipticity at 307 nm in the photostationary state is 2.4 times greater.

Chemical Papers published new progress about 126613-06-7. 126613-06-7 belongs to esters-buliding-blocks, auxiliary class Chiral Diphenols, name is (R)-[1,1′-Binaphthalene]-2,2′-diyl bis(trifluoromethanesulfonate), and the molecular formula is C22H12F6O6S2, Recommanded Product: (R)-[1,1′-Binaphthalene]-2,2′-diyl bis(trifluoromethanesulfonate).

Referemce:
https://en.wikipedia.org/wiki/Ester,
Ester – an overview | ScienceDirect Topics

Cui, Jingrong published the artcileStereocontrolled allylation of 2-amino-2-deoxy sugar derivatives by a free-radical procedure, Safety of (3aR,5R,6R,7R,7aR)-5-(Acetoxymethyl)-2-methyl-5,6,7,7a-tetrahydro-3aH-pyrano[3,2-d]oxazole-6,7-diyl diacetate, the publication is Carbohydrate Research (1998), 309(4), 319-330, database is CAplus.

Preparative routes for anomerically specific 1-C-allylation of 2-amino-2-deoxy sugars have been evaluated in a comparative study of various N-substituents and aglycons as precursors for glycosyl radicals that effectively capture an allyl group from allyltributyltin. The crystalline triacetate of 3-(2-acetamido-2-deoxy-α-D-glucopyranosyl)-1-propene was obtained in 70% yield when 2-acetamido-3,4,6-tri-O-acetyl-2-deoxy-α-D-glucopyranosyl chloride was treated with allyltributyltin under free-radical conditions, whereas the corresponding bromide led only to an oxazolidine derivative The 2-trifluoroacetamido 1-bromide analog of 2-acetamido-3,4,6-tri-O-acetyl-2-deoxy-α-D-glucopyranosyl chloride was also an effective radical source, giving the 2-trifluoroacetamido analog in 60% yield. The free amino analog was conveniently obtained via the 2-p-methoxybenzylideneamino 1-bromide analog of 2-acetamido-3,4,6-tri-O-acetyl-2-deoxy-α-D-glucopyranosyl chloride. Use of 3,4,6-tri-O-acetyl-2-deoxy-2-phthalimido-β-D-glucopyranosyl bromide as radical precursor allowed stereospecific access to β-1-C-allyl derivatives of the amino sugar. The crystalline galactosamine analog was obtained by using the galacto analog of 2-acetamido-3,4,6-tri-O-acetyl-2-deoxy-α-D-glucopyranosyl chloride, but the corresponding manno chloride gave only an oxazoline product. The 1-C-allylated amino sugar derivatives are conformationally more mobile than derivatives not having a 1-C-linked substituent.

Carbohydrate Research published new progress about 10378-06-0. 10378-06-0 belongs to esters-buliding-blocks, auxiliary class Other Aliphatic Heterocyclic,Chiral,Ester,Inhibitor,Inhibitor, name is (3aR,5R,6R,7R,7aR)-5-(Acetoxymethyl)-2-methyl-5,6,7,7a-tetrahydro-3aH-pyrano[3,2-d]oxazole-6,7-diyl diacetate, and the molecular formula is C14H19NO8, Safety of (3aR,5R,6R,7R,7aR)-5-(Acetoxymethyl)-2-methyl-5,6,7,7a-tetrahydro-3aH-pyrano[3,2-d]oxazole-6,7-diyl diacetate.

Referemce:
https://en.wikipedia.org/wiki/Ester,
Ester – an overview | ScienceDirect Topics

Wilke, Olaf published the artcileVolatile organic compounds from building products-Results from six round robin tests with emission test chambers conducted between 2008 and 2018, Name: Dimethyl adipate, the publication is Indoor Air (2021), 31(6), 2049-2057, database is CAplus and MEDLINE.

Emission testing of volatile organic compounds (VOC) from materials and products is commonly based on emission test chamber measurements. To ensure the comparability of results from different testing laboratories, their measurement performance must be verified. For this purpose, Bundesanstalt fuer Materialforschung und -pruefung (BAM) organizes an international proficiency test (round robin test, RRT) every two years using well-characterized test materials (one sealant, one furniture board, and four times a lacquer) with defined VOC emissions. The materials fulfilled the requirements of homogeneity, reproducibility, and stability. Altogether, 36 VOCs were included of which 33 gave test chamber air concentrations between 13 and 83μg/m³. This is the typical concentration range to be expected and to be quantified when performing chamber tests. Three compounds had higher concentrations between 326 and 1105μg/m³. In this paper, the relative standard deviations (RSD) of BAM round robin tests since 2008 are compared and the improvement of the comparability of the emission chamber testing is shown by the decrease of the mean RSD down to 28% in 2018. In contrast, the first large European interlaboratory comparison in 1999 showed a mean RSD of 51%.

Indoor Air published new progress about 627-93-0. 627-93-0 belongs to esters-buliding-blocks, auxiliary class Ploymers, name is Dimethyl adipate, and the molecular formula is C11H10O, Name: Dimethyl adipate.

Referemce:
https://en.wikipedia.org/wiki/Ester,
Ester – an overview | ScienceDirect Topics

Yamamoto, Takeshi published the artcileQuantitative structure-activity relationship study of N-(3-Oxo-3,4-dihydro-2H-benzo[1,4]thiazine-6-carbonyl)guanidines as potent Na/H exchange inhibitors, Safety of Ethyl 2-mercaptopropanoate, the publication is Chemical & Pharmaceutical Bulletin (2000), 48(6), 843-849, database is CAplus and MEDLINE.

The authors have previously reported that N-(4-isopropyl-2,2-dimethyl-3-oxo-3,4-dihydro-2H-benzo[1,4]oxazine-6-carbonyl)guanidine methanesulfonate salt (KB-R9032) is a potent and highly water-soluble Na/H exchange inhibitor. In a series of studies on Na/H exchange inhibitors, the authors designed and synthesized N-(3-oxo-3,4-dihydro-2H-benzo[1,4]thiazine-6-carbonyl)guanidines (I, R¹ = H, R² = H or Me and R³ = H, Me, Et, iso-Pr, Pr, Bu or pentyl) as more potent inhibitors with high water-solubility The design strategy for I was based on a quant. structure-activity relation (QSAR) study, involving the proportional relation between the biol. activity and hydrophobicity of the ring structure of N-(2H-benzo[1,4]oxazine-6-carbonyl)guanidines (II). As expected, I showed more potent activity than II. It was found by using the QSAR anal. that I were about five-fold more potent than II. The increase in potency of I well agreed with the authors previous QSAR anal. result. The most potent derivative was the methanesulfonate salt of the 4-iso-Pr derivative of I (IC₅₀=0.0091 μM). In addition to the in vitro study, the 4-iso-Pr derivative of I showed significant protective activity against ventricular fibrillation in a rat acute myocardial infarction model.

Chemical & Pharmaceutical Bulletin published new progress about 19788-49-9. 19788-49-9 belongs to esters-buliding-blocks, auxiliary class Thiol,Aliphatic hydrocarbon chain,Ester, name is Ethyl 2-mercaptopropanoate, and the molecular formula is C19H21N3O3S, Safety of Ethyl 2-mercaptopropanoate.

Referemce:
https://en.wikipedia.org/wiki/Ester,
Ester – an overview | ScienceDirect Topics

Yamamoto, Takeshi published the artcileSynthesis and quantitative structure-activity relationships of N-(3-oxo-3,4-dihydro-2H-benzo[1,4]oxazine-6-carbonyl)guanidines as Na/H exchange inhibitors, Product Details of C11H11NO4, the publication is Chemical & Pharmaceutical Bulletin (1998), 46(11), 1716-1723, database is CAplus and MEDLINE.

N-(3-Oxo-3,4-dihydro-2H-benzo[1,4]oxazine-6-carbonyl)guanidines I [R = H, Cl, OMe; R¹ = H, Me; R² = H, Me, Et, Ph; R³ = H, Me, Et, CHMe₂, Pr, Bu, CH₂CH₂OEt, hexyl] were prepared and tested for Na/H exchange inhibitory activities in order to clarify the structure-activity relationship (SAR). QSAR anal. of I indicated that the length of the 4-substituent was parabolically related to activity and that the calculated optimum 4-substituents were Pr, Et and iso-Pr groups. This SAR was similar to the SAR of the 2- and 4-substituents of 7-carbonylguanidine derivatives, although the position relative to the essential guanidinocarbonyl group was different. Larger 2-substituents, such as a Ph group were unfavorable. The most potent derivative in this series was I [R = H, R¹, R² = Me, R³ = CHMe₂] with an IC₅₀ value of 0.12 μM. The methanesulfonate salt (KB-R9032) of this compound had excellent water-solubility and showed anti-arrhythmic activity against a rat acute myocardial infarction model. KB-R9032 was selected for further investigation as a therapy for ischemia-reperfusion induced injury.

Chemical & Pharmaceutical Bulletin published new progress about 179950-77-7. 179950-77-7 belongs to esters-buliding-blocks, auxiliary class Other Aromatic Heterocyclic,Ester,Amide, name is Methyl 2-methyl-3-oxo-3,4-dihydro-2H-benzo[b][1,4]oxazine-6-carboxylate, and the molecular formula is C7H10BNO3, Product Details of C11H11NO4.

Referemce:
https://en.wikipedia.org/wiki/Ester,
Ester – an overview | ScienceDirect Topics

Gevorgyan, Ashot published the artcileFormal C-H Carboxylation of Unactivated Arenes, Safety of 3-(Methoxycarbonyl)benzoic acid, the publication is Chemistry – A European Journal (2020), 26(27), 6064-6069, database is CAplus and MEDLINE.

A formal C-H carboxylation of unactivated arenes e.g., I using CO₂ in green solvents is described. The present strategy combines a sterically controlled Ir-catalyzed C-H borylation followed by a Cu-catalyzed carboxylation of the in situ generated organoboronates. The reaction is highly regioselective for the C-H carboxylation of unactivated arenes e.g., I (1,3-disubstituted and 1,2,3-trisubstituted benzenes, 1,2- or 1,4-sym. substituted benzenes, fluorinated benzenes and different heterocycles). The developed methodol. was applied to the late-stage C-H carboxylation of com. drugs and ligands.

Chemistry – A European Journal published new progress about 1877-71-0. 1877-71-0 belongs to esters-buliding-blocks, auxiliary class Carboxylic acid,Benzene,Ester, name is 3-(Methoxycarbonyl)benzoic acid, and the molecular formula is C9H8O4, Safety of 3-(Methoxycarbonyl)benzoic acid.

Referemce:
https://en.wikipedia.org/wiki/Ester,
Ester – an overview | ScienceDirect Topics

Palagummi, Sri Vikram published the artcileThermal shrinkage reveals the feasibility of pulse-delay photocuring technique, Formula: C11H15NO2, the publication is Dental Materials (2021), 37(12), 1772-1782, database is CAplus and MEDLINE.

To resolve the feasibility of the pulse-delay photocuring technique as a clin. strategy for reducing the detrimental polymerization stress induced in dental composites during the photocuring process.Model dental composites with high and low-filler contents were cured with the pulse-delay photocuring technique using different combinations of photocuring variables (irradiance, exposure time, and delay time). Irradiance used ranged from 0.1 W/cm² to 4 W/cm². The exposure time of the first pulse varied from 0.2 s to 27.2 s and the delay times ranged from 10 s to 120 s. The radiant exposure was varied from 4 J/cm² to 20 J/cm². A cantilever-beam based instrument (NIST Standards Reference Instrument 6005) was used to implement the photocuring technique for the measurement of the polymerization properties the degree of monomer conversion, polymerization Stress induced due to shrinkage, and temperature change due to the reaction exotherm and curing light absorbance simultaneously in real-time. These properties were compared with those obtained using the conventional photocuring technique (i.e., using a constant irradiance for a fixed exposure time, a uniform exposure).There exists a min. radiant exposure, such that a reduction In the polymerization stress can be achieved without sacrificing the degree of monomer conversion by using the pulse-delay over the conventional photocuring technique. More specifically, stress reductions of up to 19% and 32% was observed with the pulse-delay when compared with the conventional photocuring technique at an irradiance of 0.5 W/cm² and 4 W/cm², resp. The reduction occurred when the exposure time of the first pulse was greater than, but closer to, the gelation time (i.e., lower than the vitrification time) of the composite, regardless of the delay time used. Lower thermal shrinkage (contraction) during the post-curing time, rather than the stress relaxation during the delay time or lower degree of monomer conversion as claimed in the literature, is the cause of the reduction In the polymerization stress.The study clarifies a long-standing confusion and controversy on the applicability of the pulse-delay photocuring technique for reducing the polymerization stress and promotes its potential clin. success for dental restorative composites.

Dental Materials published new progress about 10287-53-3. 10287-53-3 belongs to esters-buliding-blocks, auxiliary class Amine,Benzene,Ester, name is Ethyl 4-dimethylaminobenzoate, and the molecular formula is C11H15NO2, Formula: C11H15NO2.

Referemce:
https://en.wikipedia.org/wiki/Ester,
Ester – an overview | ScienceDirect Topics

Choi, Dong Hoon published the artcileEffect of photodimerization of chalcone moiety on the temporal stability of optically induced birefringence in photoresponsive polymers bearing a p-methoxyazobenzene, HPLC of Formula: 135529-02-1, the publication is Korea Polymer Journal (1999), 7(3), 189-195, database is CAplus.

We synthesized three methacrylate monomers containing chalcone moiety, mesogenic unit, and p-methoxyazobenzene chromophore, resp., and copolymers and homopolymers were prepared Trans-to-cis photoisomerization was observed under the exposure of UV. The kinetic study of trans-to-cis photoisomerization was performed in three different polymers. Reorientation of polar azobenzene mols. induced optical anisotropy under a linearly polarized light at 365 nm. The azobenzene unit underwent photoisomerization, and photodimerization was achieved in chalcone moieties under the same range light wavelength, while reorientation of azobenzene mol. was observed followed by photodimerization of chalcone moieties and the optically induced birefringence; the temporal stability was monitored without excitation light.

Korea Polymer Journal published new progress about 135529-02-1. 135529-02-1 belongs to esters-buliding-blocks, auxiliary class azo,Alkenyl,Benzene,Ester,Ether, name is 6-(4-((4-Methoxyphenyl)diazenyl)phenoxy)hexyl methacrylate, and the molecular formula is C23H28N2O4, HPLC of Formula: 135529-02-1.

Referemce:
https://en.wikipedia.org/wiki/Ester,
Ester – an overview | ScienceDirect Topics