Tag: M.W=200-250

Harwood, Stephen J. published the artcileModular terpene synthesis enabled by mild electrochemical couplings, Name: (4-Bromobut-1-yn-1-yl)trimethylsilane, the publication is Science (Washington, DC, United States) (2022), 375(6582), 745-752, database is CAplus and MEDLINE.

The synthesis of terpenes is a large field of research that is woven deeply into the history of chem. Terpene biosynthesis is a case study of how the logic of a modular design can lead to diverse structures with unparalleled efficiency. This work leverages modern nickel-catalyzed electrochem. sp²-sp³ decarboxylative coupling reactions, enabled by silver nanoparticle-modified electrodes, to intuitively assemble terpene natural products and complex polyenes by using simple modular building blocks. The step change in efficiency of this approach is exemplified through the scalable preparation of 13 complex terpenes, which minimized protecting group manipulations, functional group interconversions, and redox fluctuations. The mechanistic aspects of the essential functionalized electrodes are studied in depth through a variety of spectroscopic and anal. techniques. Safety: numerous safety warnings are provided, including hazards associated with RVC dust and pyrophoric Pd/C catalysts.

Science (Washington, DC, United States) published new progress about 69361-41-7. 69361-41-7 belongs to bromides-buliding-blocks, auxiliary class PROTAC Linker,Aliphatic Linker, name is (4-Bromobut-1-yn-1-yl)trimethylsilane, and the molecular formula is C7H13BrSi, Name: (4-Bromobut-1-yn-1-yl)trimethylsilane.

Referemce:
https://en.wikipedia.org/wiki/Bromide,
bromide – Wiktionary

Khorsand Kheirabad, Atefeh published the artcileColloidal dispersion of poly(ionic liquid)/Cu composite particles for protective surface coating against SAR-CoV-2, Name: 1-Bromododecane, the publication is Nano Select (2022), 3(1), 227-232, database is CAplus and MEDLINE.

Herein, we report a waterproof anti-SARS-CoV-2 protective film prepared by spray-coating of an aqueous colloidal dispersion of poly(ionic liquid)/copper (PIL/Cu) composite nanoparticles onto a substrate. The PIL dispersion was prepared by suspension polymerization of 3-dodecyl-1-vinylimdiazolium bromide in water at 70°C. The copper acetate salt was added into the PIL nanoparticle dispersion and in situ reduced into copper nanoparticles anchoring onto the PIL nanoparticles. Despite being waterborne, the PIL in bulk is intrinsically insoluble in water and the formed coating is stable in water. The formed surface coating by PIL/copper composite nanoparticles was able to deactivate SARS-CoV-2 virions by 90.0% in 30 min and thus may effectively prevent the spread of SARS-CoV-2 through surface contact. This method may provide waterborne dispersions for a broad range of antivirus protective surface coatings for both outdoor and indoor applications.

Nano Select published new progress about 143-15-7. 143-15-7 belongs to bromides-buliding-blocks, auxiliary class Bromide,Aliphatic hydrocarbon chain, name is 1-Bromododecane, and the molecular formula is C12H25Br, Name: 1-Bromododecane.

Referemce:
https://en.wikipedia.org/wiki/Bromide,
bromide – Wiktionary

Chun, Yong-Jin published the artcileSynthesis of ω-phthalimidoalkylphosphonates, Application of Diethyl (bromomethyl)phosphonate, the publication is Synthesis (1994), 909-10, database is CAplus.

Di-Et phthalimidoalkylphosphonates I (n = 1,2,3,4) were synthesized by the reaction of di-Et bromoalkylphosphonates with N-(tert-butyldimethylsilyl)phthalimide in the presence of tetrabutylammonium fluoride.

Synthesis published new progress about 66197-72-6. 66197-72-6 belongs to bromides-buliding-blocks, auxiliary class Aliphatic Chain, name is Diethyl (bromomethyl)phosphonate, and the molecular formula is C5H12BrO3P, Application of Diethyl (bromomethyl)phosphonate.

Referemce:
https://en.wikipedia.org/wiki/Bromide,
bromide – Wiktionary

Salman, Abbas Abdulameer published the artcileHybrid emulsifier systems: Alkyl imidazolium lactoside surfactants derived from natural resources, Synthetic Route of 143-15-7, the publication is Carbohydrate Research (2022), 108634, database is CAplus and MEDLINE.

A new series of hybrid surfactants comprising an imidazolium as a cation and a disaccharide as a non-ion were synthesized, and their aggregation behavior was also investigated. The synthetic approach used alkylation as an easily accessible route on an imidazole to attempt an economic production followed by coupling with bromoethyl lactoside to form lacto-imidazolium salts surfactants. The coupled surfactants were obtained in almost quant. yield over several steps. The surfactant surface properties in aqueous media were investigated, including critical micelle concentration (CMC), Krafft temperature, and emulsion stability were studied. The CMC measurements of the alkyl imidazolium lactoside surfactants are significantly lower than normal imidazolium surfactants, while the emulsion investigations encourage the use of alkyl imidazolium lactoside surfactants owing to stabilized assemble behavior as good as APGs.

Carbohydrate Research published new progress about 143-15-7. 143-15-7 belongs to bromides-buliding-blocks, auxiliary class Bromide,Aliphatic hydrocarbon chain, name is 1-Bromododecane, and the molecular formula is C12H25Br, Synthetic Route of 143-15-7.

Referemce:
https://en.wikipedia.org/wiki/Bromide,
bromide – Wiktionary

Sampayo, Luiz de Mello Vaz de published the artcileThe structure of 1,2-dibromotetramethylethane, Application In Synthesis of 594-81-0, the publication is Revista Portuguesa de Quimica (1961), 3(2), 57-66, database is CAplus.

It was demonstrated by x-ray diffraction that 1,2-dibromotetramethylethane crystallizes in the tetragonal system (symmetry group 4mm) with a 7.39 and c 8.14 A. The centered unit cell has Z = 2. The symmetry of the unit cell requires that the 2 mols. in it have their lowest axis of inertia along a 4-fold axis of the crystal. Under these circumstances the space group is of maximum symmetry I4/mmm, and the centers of the 2 mols. are at the origin and at the center of the unit cell. The observed intensities, to which the usual corrections including temperature and absorption corrections were applied, diverge slightly from the calculated ones. This was probably due to an imperfect determination of the crystal shape.

Revista Portuguesa de Quimica published new progress about 594-81-0. 594-81-0 belongs to bromides-buliding-blocks, auxiliary class Bromide,Aliphatic hydrocarbon chain, name is 2,3-Dibromo-2,3-dimethylbutane, and the molecular formula is C6H12Br2, Application In Synthesis of 594-81-0.

Referemce:
https://en.wikipedia.org/wiki/Bromide,
bromide – Wiktionary

Skatteboel, L. published the artcileReactions of tertiary acetylenic halides with Grignard reagents. Preparation of cumulenes, Computed Properties of 594-81-0, the publication is Tetrahedron (1965), 21(6), 1357-67, database is CAplus.

Me₂C(OH)CCCCMe (0.25 mole), 0.25 ml. CaCl₂, and a small amount of hydroquinone in 104 ml. concentrated HCl mechanically shaken 3.5 hrs. yielded 90% Me₂CClCCCCMe (I), b₁₀ 64-9°, n²⁰_D 1.5116. I (14.8 g.) in 15 ml. dry Et₂O added dropwise in 1 hr. to 170 ml. MeMgBr (0.70M) with stirring at 20°, the mixture stirred 16 hrs. and refluxed 1 hr. with collection of evolved gases trapped at -78° over H₂O, the mixture hydrolyzed with dilute aqueous HCl and the isolated product distilled gave 6.1 g. liquid, b₁₂ 50-2°, n²⁶_D 1.4998. The residue yielded 4.1 g. crystalline compound, purified by chromatography and recrystallization from MeOH to give [MeC CCCCMe₂]₂ (II), m. 140°. as chromatography of the liquid showed the presence of 64, 27, and 9% of 3 compounds (III, IV, V), separated by preparative gas chromatography. On the basis of analysis, spectroscopic data, and identity with a compound prepared by reduction of I with Zn in alc. III was shown to be Me₂C:C:CHC CMe, b₁₃ 50°, n²⁵_D 1.5023. Repeated preparative gas chromatography gave a liquid, n²⁵_D 1.4792, recrystallized at low temperature from C₅H₁₂ to give IV, Me₂CHCCCCMe, m. 27°. I (5 g.) in 30 ml. dry MeOH containing 1.5 g. Na kept 2 hrs. at 20° and refluxed 15 min., treated with H₂O and extracted with C₅H₁₂ yielded 53% V, H₂C:CMeCCCCMe, b₁₃ 53°, n²⁵_D 1.5402, extremely unstable except at low temperature under N. In one experiment the reaction mixture from the Grignard reaction was decomposed with D₂O and the compounds separated Both II and V were unchanged but the product from III, ν 2225 cm.^-1, N.M.R. lacking the band at 4.99 due to the allenic proton, was III-4-d. The new IV lacked the ir band at 1320 cm.^-1 and it was evident that D was actually incorporated at the tertiary C atom of the Me₂CH group. The gas evolved in the reaction analyzed by gas chromatography consisted of 99.9% C₂H₆ with traces of CH₄. Use of EtMgBr gave 61% C₂H₆, 39% H₂C:CH₂, with traces of CH₄. Although no cumulene was formed, the isolation of III showed that rearrangement had occurred and the reaction of Grignard reagents with tertiary acetylenic dihalides was studied. Me₂CClCCCClMe₂ (VI) (5.4 g.) in 15 ml. dry Et₂O added dropwise in 30 min. to 50 ml. MeMgBr (1.54M) with stirring at 20° and the mixture stirred 1 hr., refluxed 1 hr., and hydrolyzed with dilute HCl (all operations under N) yielded 92% Me₂C:C:C:CMe₂ (VII), m. 40°. The gas evolved was 99.9% C₂H₆, but with EtMgBr consisted of 51:49 C₂H₆-H₂C:CH₂. VII was also produced by treatment of VI with Zn. VII was extremely sensitive to O with formation of a polymeric peroxide, isolated by extraction with hot CH₂Cl₂ to CHCl₃ to give crystalline material, C₈H₁₂O₂, m. 112-13° ozonized in CCl₄ followed by treatment with Zn and H₂O to give Me₂CO. Me₂CCl(C:C)₂CClMe₂ (VIII) (10.1 g.) in 15 ml. dry Et₂O added dropwise in 1 hr. to 80 ml. MeMgBr (1.5M) with stirring at 20°, the mixture kept 1 hr. at 20° and decomposed with dilute HCl, the Et₂O solution separated and dried gave ir spectrum, ν 2002 1625 cm.^-1, and uv maximum 215, 228, 308, 321 mμ. Any attempt to isolate the cumulene gave highly unstable polymeric material, explosive at 70-80°, ν 1140 cm.^-1, and containing considerably less O than the above peroxide. On the basis of the assembled data the cumulene structure, Me₂C:C:C:C:C:CMe₂ was assigned to the compound In the reaction of both VI and VIII dehalogenation had occurred and it was shown that the vicinal dihalide, Me₂CBrCBrMe₂ (IX) readily reacted with MeMgBr to yield Me₂C:CMe₂ (X) as the sole isolable product. Production of C₂H₆ from reactions with MeMgBr suggested that the dehalogenation reaction with IX to give the volatile X might be useful as a way of dimerizing Grignard reagent radicals. MeMgBr (140 ml., 1.4M) in Et₂O added dropwise in 2 hrs. to 19.5 g. IX in 25 ml. dry Et₂O and the mixture refluxed 1 hr., cooled, and hydrolyzed with dilute HCl and the washed and dried Et₂O layer fractionated yielded 76% X, b. 70-2°, n²⁰_D 1.4101. The evolved gases contained 99.9% C₂H₆. Similar reaction of IX with EtMgBr gave X and evolved 52% C₂H₆, 48% H₂C:CH₂, and traces of CH₄. Reaction of IX with PhMgBr gave only X and 71% Ph₂, m. 69-70°. PhCCH (5.1 g.) in 20 ml. dry Et₂O treated with 34 ml. 1.48M MeMgBr and the mixture refluxed 6 hrs., the mixture worked up as usual and the Et₂O distilled under reduced pressure, the residue recrystallized from MeOH to yield 63% PhCCCPh, m. 87-8°, and the Et₂O distillate analyzed by gas chromatography showed the presence of 62% X and PhCCH. Distillation of the distillate recovered 1.4 g. PhCCH. The formation of the allene and cumulenes was rationalized by a functional exchange-elimination mechanism involving radicals.

Tetrahedron published new progress about 594-81-0. 594-81-0 belongs to bromides-buliding-blocks, auxiliary class Bromide,Aliphatic hydrocarbon chain, name is 2,3-Dibromo-2,3-dimethylbutane, and the molecular formula is C8H11NO, Computed Properties of 594-81-0.

Referemce:
https://en.wikipedia.org/wiki/Bromide,
bromide – Wiktionary

Streitwieser, Andrew Jr. published the artcileThe application of Taft’s equation to polar effects in solvolyses, Application In Synthesis of 594-81-0, the publication is Journal of the American Chemical Society (1956), 4935-8, database is CAplus.

The Taft equation, log (k/k₀) = σ*ρ* (cf. C.A. 48, 11888f), was applied to the solvolysis of secondary carbinyl sulfonates in AcOH, of tertiary halides in aqueous EtOH, and of primary tosylates in EtOH, with satisfactory results. Driving forces for anchimeric assistance are derived from the correlations.

Journal of the American Chemical Society published new progress about 594-81-0. 594-81-0 belongs to bromides-buliding-blocks, auxiliary class Bromide,Aliphatic hydrocarbon chain, name is 2,3-Dibromo-2,3-dimethylbutane, and the molecular formula is C10H15ClO3S, Application In Synthesis of 594-81-0.

Referemce:
https://en.wikipedia.org/wiki/Bromide,
bromide – Wiktionary

Sysoeva, N. D. published the artcileThe application of the Chugaev xanthic reaction to secondary-tertiary and ditertiary glycols. II. Experimental part. The effect of sodium xanthate on trimethylethylene dibromide, Safety of 2,3-Dibromo-2,3-dimethylbutane, the publication is Trudy Uzbekskogo Inst. Narodnogo Khoz. (1940), 1-11, database is CAplus.

The heating of the dibromides of the tri- and tetramethylethylenes with Na xanthate on a water bath at 60-70° resulted in the formation of tri- and tetramethylethylenes the separation and identification of which are described in detail. Through Khim. Referat. Zhur. 4, Number 7-8, 40-1(1941).

Trudy Uzbekskogo Inst. Narodnogo Khoz. published new progress about 594-81-0. 594-81-0 belongs to bromides-buliding-blocks, auxiliary class Bromide,Aliphatic hydrocarbon chain, name is 2,3-Dibromo-2,3-dimethylbutane, and the molecular formula is C12H15NO, Safety of 2,3-Dibromo-2,3-dimethylbutane.

Referemce:
https://en.wikipedia.org/wiki/Bromide,
bromide – Wiktionary

Wang, Ya-zhen published the artcileSynthesis of 5-bromo-1-methyl-2-phenyl-1H-benzimidazole, Safety of 4-Bromo-N-methyl-2-nitroaniline, the publication is Huaxue Yanjiu Yu Yingyong (2015), 27(11), 1721-1725, database is CAplus.

5-Bromo-1-methyl-2-phenyl-1H-benzimidazole was intermediate to prepare anti-cancer pharmaceuticals, and organic electroluminescence devices. The key intermediate N-(4-bromo-2-nitrophenyl)-N-methylbenzamide was prepared using N-methyl-2-nitroaniline as starting material which was consisted of benzene ring bromination, N-benzoylation reaction, following with reaction of nitroredn. and closed ring reaction of intramolecularly dehydration. The target product 5-bromo-1-methyl-2-phenyl-1H-benzimidazole (I) was synthesized in excellent yield. The chem. structures were characterized by ¹H-NMR, ¹³C-NMR and IR, and purity was determined by HPLC.

Huaxue Yanjiu Yu Yingyong published new progress about 53484-26-7. 53484-26-7 belongs to bromides-buliding-blocks, auxiliary class Bromide,Nitro Compound,Amine,Benzene, name is 4-Bromo-N-methyl-2-nitroaniline, and the molecular formula is C9H6BrNO, Safety of 4-Bromo-N-methyl-2-nitroaniline.

Referemce:
https://en.wikipedia.org/wiki/Bromide,
bromide – Wiktionary

Wohl, A. published the artcileBromination of unsaturated compounds with N-bromoacetamide, a contribution to the study of the course of chemical processes, Computed Properties of 594-81-0, the publication is Berichte der Deutschen Chemischen Gesellschaft [Abteilung] B: Abhandlungen (1919), 51-63, database is CAplus.

It has now become quite widely accepted that substitution reactions are often preceded by addition reactions and the present investigation was carried out in the course of a search for reactions which would make it possible to decide with certainty whether there is really a primary addition and, if so, whether it is molecular or atomic. W. found, e. g., that the reaction Me₂C:CMe₂ + AcNHBr (a) → Me₂C:CMeCH₂Br + AcNH₂ occurs under such conditions (good cooling in Et₂O or Me₂CO) that the (a) is not dissociated at all or only to a very minute extent; no HBr can be detected. This reaction can in no way be explained as taking place by addition of the residues Br and AcNH of the (a) to the two C atoms of the double bond, for an acetylated bromoamine would split off HBr and not AcNH₂. Moreover, the behavior of (a) towards Me₂C:CHMe (see below) also shows that the Br does not combine with either of the unsaturated C atoms. There, therefore, remains but one possibility, that the primary addition occurs through subsidiary valences on (a) and one or both of the trivalent C atoms and the resulting unstable structure with the loosest union between Br and N then loses AcNH, forming AcNH₂ with the most labile H atom after the Br and this H atom, obeying the law of neutralization, have exchanged places. According to W.’s views, the high additive power of (a) depends on the union, the spatial proximity, of the two fields of affinity of the unsaturated negative atoms -NBr, just like H₂N.OH, H₂N.NH₂, HO.NO, (HO)₂SO, HN:C, etc. Compounds without this union, like the hydrazonium salts, H₂NNMe₃I, are quite indifferent, e. g., towards aldehydes. Me₂C:CHMe and (a) under such conditions (sufficient dilution and cooling) that AcNH₂ seps. and the Br derivative remains in solution give exclusively a di-Br compound C₅H₈Br₂. If, however, equimol. amounts of Me₂C:CHMe and (a) are brought together in cold Et₂O they combine and sep. practically quant. as an oil which, when the Et₂O is poured off, undergoes an energetic reaction just like when Me₂C:CHMe and (a) are brought together without a diluent. It is, therefore, not the addition product stable at low temperatures which determines the course of the substitution reaction but some part of it (which could not be isolated) in the mixture formed when the temperature is raised. In the substitution reaction it is one of the primary H atoms, not the tertiary atom, which is replaced. The primary addition is, therefore, determined by the coóperation of the Br-N secondary valences and the C double bond, and the further course of the reaction by the mobility of the H atoms; according to the well-known rule, the double bond loosens the H on the adjacent C atom. In harmony with these views it was found that (a) does not attack compounds saturated in the usual sense (except Me₃CBr) and a series of compounds unsaturated in the ordinary sense but lacking the conditions of easy addition or of mobile H atoms (EtBr, iso-PrBr, (CH₂Br)₂, PhCH₂Br and CH₂(CO₂Et)₂ in the first group and C₂H₄, C₂H₂, maleic and fumaric acids, PhCH:CHCO₂H, PhCH:CHCO₂Et and PhCH:CHCHO in the second group). Malonic ester, in spite of the mobile H atoms, lacks a grouping appropriate for the primary addition; this, however, is present in the derivative EtO₂CCH₂CONH₂ which in Me₃CO smoothly forms the compound EtO₂CCHBrCONH₂, the transient yellow color appearing during the course of its preparation indicating the formation of a Br-N compound with pentavalent N in which the migration of the Br from N to C occurs by intramol. substitution. The indifference of the other compounds of the second group is easily explained by the absence of a reactively influenced H atom. On the other hand, AcCH₂CO₂Et, PhOH and, to a less marked degree, PhOMe react with (a) just like Me₂C:CMe₂ and Me₂C:CHMe. The same is true of Me₃CBr, PhCH:CH₂, MeCH:CHCO₂H, NCCH₂CO₂Et, AcH, HCO₂H and HCO₂Et. The (a) used was recrystallized from C₆H₆, m. 108° and was colorless; as diluents were used Et₂O (in which it is not soluble but dissolves as the reaction proceeds and AcNH₂ seps.) or Me₂CO which dissolves (a) readily without being itself markedly brominated in the cold. In general, as soon as the starch-iodide reaction was no longer given, the AcNH₂, was removed, after addition of Et₂O, by shaking with Na₂CO₃ and washing with H₂O and the H₂O-insoluble layer was dried with Na₂SO₄ and fractionated in vacuo. Without a diluent (a) acts on easily brominated compounds with much evolution of heat, darkening and violent decomposition, the unattacked (a) itself being thereby decomposed with liberation of Br. From 10 g. cold Me₂C:CHMe treated with four 10-g. portions of (a) in 60 cc. Me₂CO was obtained 9 g. of a compound, C₅H₈Br₂ (b) (found 69.74% Br; calculated, 70.14), b₁₂ 54-5°, decolorizes KMnO₄ and Br-H₂O in alc.; no mono-Br derivative is formed, even when a large excess of Me₂C:CHMe is used (20 g. to 20 of Br). Me₂C:CBrMe, prepared by Bauer’s method (Bull. soc. chim. 2, 149(1860)) but from pure Me₂C:CHMe instead of amylene, b₇₆₆ 119-20°; it reacts much more slowly than Me₂C:CHMe with (a); 14.9 g. added at room temperature to 13.8 g. (a) in 60 cc. Me₂CO and allowed to stand 24 hrs. without cooling, gave, besides unchanged Me₂C:CBrMe, a fraction b₂₅ 96-8° with 69.43% Br. This dibromotrimethylethylene partly polymerizes on cooling and unlike (b) has an intense odor and attacks the eyes. From 10 g. Me₂C:CMe₂ in 36 cc. cold Et₂O and 16 g. (a) is obtained about 3 g. of not quite pure bromotetramethylethylene (found 46.3% Br; calculated 49.0%), b₁₅, 60-90°, decolorizes KMnO₄, easily decomposes and polymerizes. Me₃CBr (37 g.) in 10 cc. cold Et₂O slowly treated with 37 g. (a) yields 7 g. Me₂C(CH₂Br)Br, b₃₆ 60-1°, b. 149°. From 44.3 g. PhOH in 145 cc. cold Et₂O treated at 12 hr. intervals With, 20, 20 and 25 g. (a) is obtained p-BrC₆H₄OH, m. 64°, b₂₁ 1.39°, b, 236°. PhOMe (10.8 g.) and 13.8 g. (a) in 65 cc. Me₂CO after 24 hrs. at room temperature gave 17 g. p-BrC₆H₄OMe, m. 11-1.5°, b. 215°. AcCH₂CO₂Et (21.7 g.) in 100 cc. cold Et₂O treated in the course of 1 day with 8 + 8 + 7 g. (a) yields 15 g. AcCHBrCO₂Et, b₁₈ 106-8°. From 2 g. EtO₂CCH₂CONH₂ (prepared by heating EtO₂CCH₂C(OEt):NH.HCl at 125-30°) in 5 cc. cold Me₂CO, slowly treated with 2 g. (a) in 5 cc. Me₂CO and allowed to stand 24 hrs. to disappearance of the yellow color and the starch-iodide reaction, is obtained a mixture of AcNH₂ and EtO₂CCHBrCONH₂

Berichte der Deutschen Chemischen Gesellschaft [Abteilung] B: Abhandlungen published new progress about 594-81-0. 594-81-0 belongs to bromides-buliding-blocks, auxiliary class Bromide,Aliphatic hydrocarbon chain, name is 2,3-Dibromo-2,3-dimethylbutane, and the molecular formula is C19H24BNO2, Computed Properties of 594-81-0.

Referemce:
https://en.wikipedia.org/wiki/Bromide,
bromide – Wiktionary