Category: 18928-94-4

Yokohama, Shuichi published the artcileSynthesis and antiallergy activity of [1,3,4]thiadiazolo[3,2-a]-1,2,3-triazolo[4,5-d]pyrimidin-9(3H)-one derivatives. II. 6-Alkyl- and 6-cycloalkylalkyl derivatives, HPLC of Formula: 18928-94-4, the publication is Chemical & Pharmaceutical Bulletin (1992), 40(9), 2391-8, database is CAplus and MEDLINE.

A series of 6-alkyl- or 6-(cycloalkylalkyl)-[1,3,4]thiadiazolo[3,2-a]-1,2,3-triazolo[4,5-d]pyrimidin-9(3H)-ones, including I (R = cyclopentylethyl, cyclopentylpropyl, cyclohexylmethyl, cyclohexylpropyl, cycloheptylethyl, cyclooctylethyl, cyclododecylethyl), was synthesized from the corresponding 1,3,4-thiadiazol-5-amines II and the antiallergic activities of the products were evaluated. Among these compounds 6-(2-cyclohexylethyl)-[1,3,4]thiadiazolo[3,2-a]-1,2,3-triazolo[4,5-d]pyrimidin-9(3H)-one (I, R = cyclohexylethyl), whose x-ray crystallog. stereostructure was determined, is a promising new antiallergic agent, which has low toxicity and dual activity as a leukotriene D₄ receptor antagonist and as an orally active mast cell stabilizer.

Chemical & Pharmaceutical Bulletin published new progress about 18928-94-4. 18928-94-4 belongs to bromides-buliding-blocks, auxiliary class Bromide,Aliphatic cyclic hydrocarbon, name is (2-Bromoethyl)cyclopentane, and the molecular formula is C9H6N2O2, HPLC of Formula: 18928-94-4.

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

Abiru, Toichi published the artcileNucleosides and nucleotides. 107. 2-(Cycloalkylalkynyl)adenosines: adenosine A₂ receptor agonists with potent antihypertensive effects, Safety of (2-Bromoethyl)cyclopentane, the publication is Journal of Medicinal Chemistry (1992), 35(12), 2253-60, database is CAplus and MEDLINE.

Adenosine receptor-binding profiles in rat brain tissues and antihypertensive effects in spontaneously hypertensive rats (SHR) of a series of 2-(cycloalkylalkynyl)adenosines, e.g. I [R = Ph, CH₂CH₂Ph, C(OH)Me₂, cyclopentyl, cyclohexyl], and their congeners are described. MSBAR of this series of compounds I is discussed, focusing on the length of the alkynyl side chain, and bulkiness of the terminal cycloalkyl substituents in terms of binding activity and cardiovascular effects. I had a preferential affinity of for A₂ receptors. Of these derivatives, 2-(3-cyclopenyl-1-propyn-1-yl)adenosine (II) exhibited the most selective affinity for A₂ receptors. In the C-2 binding region of adenosine, compounds often have potent and/or selective A₂ activity from introduction of an acetylenic group at the C-2 position followed by one methylene residue further followed by a hydrophobic substituent such as a cycloalkyl ring at the terminal position of the alkynyl side chain. I.v. injection of II up to 100 μg/kg had a potent hypotensive effect without a marked decrease in heart rate in anesthetized SHR. These compounds caused a marked bradycardia upon i.v. administration in anesthetized SHR. Oral administration of II (0.1-1 mg/kg) had a potent and long-lasting antihypertensive effect in conscious SHR.

Journal of Medicinal Chemistry published new progress about 18928-94-4. 18928-94-4 belongs to bromides-buliding-blocks, auxiliary class Bromide,Aliphatic cyclic hydrocarbon, name is (2-Bromoethyl)cyclopentane, and the molecular formula is C7H13Br, Safety of (2-Bromoethyl)cyclopentane.

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

v. Braun, Julius published the artcileTransformations of cyclopentadiene, Application of (2-Bromoethyl)cyclopentane, the publication is Berichte der Deutschen Chemischen Gesellschaft [Abteilung] B: Abhandlungen (1937), 1750-60, database is CAplus.

It had been found (C. A. 22, 1146) that 2-cyclopentyl chloride (I) reacts like allyl chloride with aromatic Grignard reagents and the resulting arylcyclopentenes take up HBr to form 2-arylcyclopentyl bromides As was expected, nonaromatic Grignard reagents act in the same way with I and addition of HBr to the products offers no difficulty but, contrary to the aromatic compounds, it results in the formation of 3-alkylcyclopentyl bromides. Their structure was proved by the reaction recently described (C. A. 28, 2329.3): replacement of the Br by CO₂H by means of Mg and CO₂, α-bromination of the acid, and conversion of the Br acid into the acid chloride which with NaN₃ gave a 3-alkylcyclopentanone. HBr thus adds to the alkylcyclopentenes in just the opposite way to its addition to the aryl compounds O and halogens, like Ph, attract electrons but their effect decreases rapidly with distance and, as was expected, β-2-cyclopentenylethyl alc. (II) heated with HBr gave, together with some of the unsaturated bromide (III), the saturated β-(3-bromocyclopentyl) ethyl bromide (IV). It was attempted to prove the structure of IV by replacing both Br atoms with CO₂H but the dicarboxylic acid could not be obtained pure. That, however, it was not the 2-Br compound was indicated by the fact that with 1 mol. malonic ester and 2 atoms Na it gave, along with high-mol. compounds, and a brominated ester of lower mol. weight, only a small amount (30%) of a compound C₁₄H₂₂O₂ (V). Had the ring-substituted Br in IV been in the 2-position, the strainless bicyclo (0.3.3)octane derivative would undoubtedly have been formed very smoothly. V is believed to be the bicyclo (1,2,3) octane It is decarboxylated to the monocarboxylic acid (VI) by means of which it is hoped to develop the field of these bicyclo compounds, representatives of which (with the exception of the Komppa ketone) are as yet known only in a few complex derivatives of the camphor series. Thus far it has not been possible to pass from IV to the parent hydrocarbon of the bicyclo(1.2.2.)heptane series; as was to be expected from the strain existing in the latter system, the action of Na on IV is exclusively extramol. and there results a mixture, boiling within wide limits, of hydrocarbons (C₇H₁₂)_n of varying mol. weight 2-Ethylcyclopentene (VII) (30% yield), b₇₆₈ 99-103°, d₄²⁰ 0.7874, n_D²⁰ 1.43030. It readily adds Br in CS₂ to form a liquid dibromide, b₁₂ 98-100°, faintly yellow but soon decomposing and darkening. 3-Bromo-1-ethylcyclopentane (65% from VII shaken 50 hrs. with 2-3 volumes fuming HBr), b₄₂ 84-6°, d₄²⁰ 1.2597. It reacts readily with Mg and when the product is treated with CO₂ and worked up in the usual way it gives the Na₂CO₃-insoluble 3,3′-diethylbicyclopentyl, b₁₅ 125°, d₄¹⁵ 0.8757, n_D²⁰ 1.47097, and the Na₂CO₃-soluble 3-ethylcyclopentanecarboxylic acid, b₁₅ 132-4°, whose acid chloride, b₁₁ 176-8°, with 1 mol. Br at 125° gives almost quantitatively the α-Br derivative, b₁₁ 110°, and this, in pyridine solution or suspension, heated with NaN₃, then treated with alc. and alkali, acidified with HCl after 15 min. and distilled with steam, yields 3-ethylcyclopentanone, b. 150°, forming a semicarbazone, m. 175°, and with m-O₂NC₆H₄CHO, alc. and a trace of alkali, a lemon-yellow condensation product, C₂₀H₁₈O₅N₂, m. 142°. 2-Isoamylcyclopenten (60%), b₅₉ 86-7°, does not darken on standing, d₄²² 0.7969. 3-Bromo-1-isoamylcyclopentane, b₁₅ 109-10°; 3-carboxylic acid, b₂₀ 160°, d₄^20.5 0.9566. 2-Dodecylcyclopentene (50%), b₁₅ 172°, d₄¹⁶ 0.8262, n_D²⁰ 1.45667. Addition of HBr requires long heating, a considerable part of the hydrocarbon remaining unattacked even after 15 hrs. The 3-bromo-1-dodecylcyclopentane b_0.1 163°, d₄^14.5 0.9811. Mg and CO₂ give, with some 3-carboxylic acid, m. 29°, chiefly dodecylcyclopentane, b₁₅ 175°, d₄¹⁸ 0.8280, n_D²⁰ 1.45737 and 3,3′-didodecylbicyclopentyl, b_0.2 260° (the latter is a semi-solid thick oil, probably consisting of a mixture of stereoisomers). The cyclopentene forms a dibromide, b_0.2 180° without appreciable decomposition but becomes discolored on standing. C₅H₉MgCl and I react very vigorously, yielding somewhat more than 60% 2-cyclopentenylcyclopentane, b₉ 60-4°, d₄²⁰ 0.8838; shaken 60 hrs. with fuming HBr, it gives almost 80% 3-bromobicyclopentyl, b₉ 115°, which with Mg and CO₂ yields bicyclopentyl, b₉ 67°, almost pure tetracyclopentyl, (C₅H₉C₅H_8^–)₂, b₉ 205-7°, and about 30% bicyclopentyl-3-carboxylic acid, b₁₃ 172°, d₄¹⁹ 1.0398; acid chloride, b₁₀ 125°, gives 70% of the α-Br derivative, faintly yellow, b_0.3 128-32°, which with NaN₃ yields 3-cyclopentylcyclopentanone, volatile with steam (oxime, b₁₀ 145-6°, m. 46°; semicarbazone, m. 184°; bis(m-nitro-benzal) derivative, yellow-red, m. 172°). 2-Cyclopentenyl-cyclohexane (60%), b₁₂ 80-5°, d₄¹⁸ 0.8995, n_D²⁰ 1.48698. 3-Bromo-l-cyclohexylcyclopentane (70%), b₁₁ 132-6°, becomes yellowish and splits off a little HBr on standing; Mg and CO₂ give cyclopentylcyclohexane, b₁₁ 86-8°, d₄²³ 0.8886, n_D²⁰ 1.47491, 15% 3,3′-dicyclohexylbicyclopentyl, b_0.1 180°, d₄¹⁸ 0.9592, n_D²⁰ 1.51290, and about 15% 3-cyclohexylcyclopentanecarboxylic acid, b₁₁ 180°, d₄¹⁷ 1.0343, n_D²⁰ 1.49255; the acid chloride, b₁₁ 142-4°, gives an α-Br derivative, b_0.05 140-2°, which with NaN₃ yields 3-cyclo-hexylcyclopentanone, b₁₀ 126°, d₄¹⁹ 0.9730, n_D²⁰ 1.48476 (semicarbazone, m. 186°; bis(m-nitrobenzal) derivative, orange, m. 122°). Et 2-cyclopentenylacetate, from the acid heated 3 hrs. on the water bath with 2 parts by weight of EtOH and 0.1 part concentrated H₂SO₄, b₁₂ 81°. With 10 atoms Na in EtOH it gives 70% II, b₁₅ 82-3°, d₄^23.5 0.9432, n_D²⁵ 1.4695, vigorously decolorizes KMnO₄, readily takes up 2 H atoms with Pd to give β-cyclopentylethyl alc. (also obtained from C₅H₉CH₂CO₂Et with Na and alc.), bit 84-5°,which with HBr at 100° gives almost 100% of the bromide, C₅H₉CH₂CH₂Br, b₁₁ 70-1°. The fraction b_0.4 below 100° (chiefly around 70°) of the product of the reaction of II with HBr and which consists chiefly of III with unchanged II, gives with NHMe₂ in benzene at 100° the unsaturated base, C₅H₇CH₂CH₂NMe₂, b₁₃ 66-8°, d₄²¹ 0.8291 (picrate, m. 136-8°; chloroplatinate, m. 148°; methiodide, m. 223°). IV, b_0.4 100°, darkens only on long standing. V, b₁₂ 155-60°; free dicarboxylic acid, powder, m. 189-90° (foaming) with formation of VI, b₁₃ 150-2°, d₄²⁶ 1.0603.

Berichte der Deutschen Chemischen Gesellschaft [Abteilung] B: Abhandlungen published new progress about 18928-94-4. 18928-94-4 belongs to bromides-buliding-blocks, auxiliary class Bromide,Aliphatic cyclic hydrocarbon, name is (2-Bromoethyl)cyclopentane, and the molecular formula is C16H14O6, Application of (2-Bromoethyl)cyclopentane.

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

Rudler, H. published the artcileTungsten(0) alkylidene complexes stabilized as pyridinium ylides: new aspects of their synthesis and reactivity, Recommanded Product: (2-Bromoethyl)cyclopentane, the publication is Journal of Organometallic Chemistry (2001), 571-587, database is CAplus.

The interaction of dihydropyridines with alkoxycarbene complexes of tungsten has been shown to lead to pyridinium ylide complexes: this transformation has now been applied to the synthesis of a hydroxyl-containing ylide complex by ring-opening of the pentacarbonyl (2-oxacyclopentylidene)tungsten(0) complex and to the synthesis of a series of chiral ylide complexes both from chiral and non-chiral carbene complexes by the use of dihydropyridines and dihydronicotines, resp. The transfer of the alkylidene moiety of these complexes to nucleophilic olefins will be outlined and discussed. Especially relevant is the interaction of these pyridinium ylide complexes with unsaturated substrates such as dihydropyridines, enamines, and β-alkoxy bis(trimethylsilyl) ketene acetals. This latter reaction leads to conjugated carboxylic acids, and has been be applied to a new synthesis of a honey bee pheromone, the queen substance.

Journal of Organometallic Chemistry published new progress about 18928-94-4. 18928-94-4 belongs to bromides-buliding-blocks, auxiliary class Bromide,Aliphatic cyclic hydrocarbon, name is (2-Bromoethyl)cyclopentane, and the molecular formula is C7H13Br, Recommanded Product: (2-Bromoethyl)cyclopentane.

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