Sodium imidazole

Sodium imidazolate (Naim), sodium cyanide, and other reagents smoothly deacetylate the cyclic 2,3-sulfamidate 126 (Equation 32) <1997T5863>. 

A slurry of sodium imidazole (50 mmol) in 30 ml of THF was treated with the slow addition of triethylborane (100 mmol) and then stirred for 5 hours at ambient temperature. The mixture was next concentrated and a brown oil isolated. The crude product was isolated in 98% yield and used without additional purification. 

The present approach is to prepare an imidazolate bridged bimetallic center that would prevent the two metal ions from migrating away from each other when the bridge is broken. The preparation involves the synthesis of a dinuclear cryptate macrocycle containing two Cu(II) ions and where a substrate such as sodium imidazolate is able to bind. 

Resorcinol or hydroquinone production from m- or -diisopropylben2ene [100-18-5] is realized in two steps, air oxidation and cleavage, as shown above. Air oxidation to obtain the dihydroperoxide (DHP) coproduces the corresponding hydroxyhydroperoxide (HHP) and dicarbinol (DC). This formation of alcohols is inherent to the autooxidation process itself and the amounts increase as DIPB conversion increases. Generally, this oxidation is carried out at 90—100°C in aqueous sodium hydroxide with eventually, in addition, organic bases (pyridine, imidazole, citrate, or oxalate) (8) as well as cobalt or copper salts (9). 

Most peroxyoxalate chemiluminescent reactions are catalyzed by bases and the reaction rate, chemiluminescent intensity, and chemiluminescent lifetime can be varied by selection of the base and its concentration. Weak bases such as sodium saUcylate or imidazole are generally preferred (94). 

Deacylations are known. C-Acyl groups in 1,3,4-thiadiazoles are cleaved by sodium ethoxide in ethanol (68AHC(9)165). Imidazole-2-carbaldehyde behaves similarly, yielding imidazole and ethyl formate this reaction involves an ylide intermediate. 3-Acylisoxazoles (405) are attacked by nucleophiles in a reaction which involves ring opening (79AHC(25)147). 

Attempted diazotization in dilute acid sometimes yields primary nitroso compounds. Reactions of 3- and 5-amino-1,2,4-thiadiazoles with sodium nitrite and acid give primary nitrosamines (e.g. 432->433) (65AHC(5)n9) which can be related to the secondary nitrosamines (434) prepared in the normal way. 1-Substituted 5-aminotetrazoles with nitrous acid give stable primary nitrosamines (435). Primary nitrosamines have been isolated in the imidazole series. 

Imidazole, 2-aryl-4-phenyl-5-trifluoromethyl-synthesis, 5, 483 Imidazole, azido-reactions, 5, 442 Imidazole, 2-azido-, 5, 415 cyclization, 6, 980 reactions, 5, 96 with sodium, 5, 442 tautomerism, 5, 371 Imidazole, benzoyl-IR spectra, 5, 30 Imidazole, 2-benzoyl-4-phenyl-... 

Sulfonamides (R2NSO2R ) are prepared from an amine and sulfonyl chloride in the presence of pyridine or aqueous base. The sulfonamide is one of the most stable nitrogen protective groups. Arylsulfonamides are stable to alkaline hydrolysis, and to catalytic reduction they are cleaved by Na/NH3, Na/butanol, sodium naphthalenide, or sodium anthracenide, and by refluxing in acid (48% HBr/cat. phenol). Sulfonamides of less basic amines such as pyrroles and indoles are much easier to cleave than are those of the more basic alkyl amines. In fact, sulfonamides of the less basic amines (pyrroles, indoles, and imidazoles) can be cleaved by basic hydrolysis, which is almost impossible for the alkyl amines. Because of the inherent differences between the aromatic — NH group and simple aliphatic amines, the protection of these compounds (pyrroles, indoles, and imidazoles) will be described in a separate section. One appealing proj>erty of sulfonamides is that the derivatives are more crystalline than amides or carbamates. 

Tetraazafulvalenes bearing two pyrazole subunits could be prepared by an original way. Tlius, treatment of benzylidene acetophenone with iso-pentylnitrite leads to an A, A -dihydroxy-bipyrazolyl-A, A -oxide, which in turn can be oxidized to TAF of type 100 (72CC961, 79JOC3211). Another type of oxidative dimerization was observed by the reaction of the electron-rich l-methyl-2,4-bis(dimethylamino)imidazole with silver salts (83TL3563). A bis-cation was isolated in 30% yield in the presence of sodium tetrafluo-roborate an unsymmetrical structure 101 was predicted from its NMR data (Scheme 40). 

This trend is also observed in the reactions with nitrogen- and carbon-centered nucleophiles (2001H425). Thus, the reaction of 109 with sodium indolyl in DMF affords methyl 2-(indol-l-yl)indole-3-carboxylate (188, 77%). In better yield, 2-(indol-l-yl)indole-3-carbaldehyde (189, 95%) is formed in the corresponding reaction (99H1157) of 115a (Scheme 28). Sodium imidazolyl reacts with 109 in DMF at 60°C to afford methyl 2-(imidazol-l-yl)indole-3-carboxylate (190,28%), methyl indole-3-carboxylate (191,11 %), and unreacted 109 (36%). In contrast, under the same conditions, 110 and 115a provide higher yields of methyl 2-(imidazol-... 

One method to transform imidazolium salts (00AGE3773) into carbene ligands, imidazol-2-ylidenes, is by deprotonation with sodium hydride or other suitable hydride in a mixture of THE and liquid ammonia (73JCS(D)514, 96CEJ1627, 98IC6412). 

It is noteworthy that carbene function may be manifested in the derivatives of tris(imidazol-l-yl)borate 44 (96AGE310). Its reaction first with n-butyllithium, then with iron(II) chloride, and finally with sodium tetraphenylborate gives the iron(III) carbene derivative 45. 

Imidazole with [(T -C Hg)RuCl2]2 in the presence of sodium methylate gives most probably the tetrameric [(T) -C Hg)RuCl(p-im)]4 where the imidazolate anion performs the N, A -bridging function (93ICA(206)15). 

Displacement of bromine on phenacyl halide with imidazole gives Reduction with sodium borohydride followed by displacement with 2,6-dichloro-benzyl alcohol in HMPA then produces antifungal orconazole (37). ... 

An imidazole derivative which is also a hypotensive agent by virtue of adrenergic a-2-receptor blockade is imiloxan (75). Its synthe.sis begins by conversion of 2-cyanomethyl-1,4-benzodioxane (72) to its iminosMhylether with anhydrous HC in clhanol (73). Reaction of the latter with aminoacetaldehyde diethylacetal and subsequent acid treatment produces the imidazole ring (74). Alkylation of 74 with ethyl iodide mediated by sodium hydride completes the synthesis [251. 

Cefpimizole (51) appears to be less active in vitro than cefotaxime and cefoperazone and to have a somewhat narrower activity spectrum although some strains of Pseudomonas are susceptible. It is not orally active, but its performance in vivo appears superior to what would be expected from its in vitro data. Its synthesis begins by acylation of cephaloglycin (48) with the bis acid chloride of imidazole-4,5-dicarboxylic acid (49) to give amide 50. The acetyl moiety at C-3 of this intermediate is displaced with 4-pyridineethanesulfonic acid and sodium iodide to give cef-pimazole (51) [16]. 

N,N -dimethyloxaldiamide is reacted with PCI5 to give 4-chloro-1-methyl imidazole. This is nitrated with HNO3 to give 5-nitro-1-methyl-4-chloroimidazole. Then, a mixture of 4.6 grams of anhydrous 6-mercaptopurine, 5 grams of 1-methyl-4-chloro-5-nitroimidazole and 2.5 grams of anhydrous sodium acetate in 100 ml of dry dimethyl sulfoxide was heated at 100°C for 7 hours. 

In order to complete the reaction, heating at 50°C is carried out for 3 hours. After cooling, one liter of benzene is added and the reaction mixture is stirred, then washed salt-free with water. The benzene solution is dried over anhydrous sodium sulfate, filtered and concentrated by evaporation giving 167 g crude 1-(o-chlorophenylbisphenylmethyl)-imidazole. By recrystallization from acetone, 115 g (= 71% of the theory) of pure 1-(o-chlorophenyl-bisphenylmethyD-imidazole of MP 154° to 156°C are obtained. 

A suspension of 10.3 parts of a-(2,4-dichlorophenyl)-imidazole-1-ethanol and 2.1 parts of sodium hydride in 50 parts of dry tetrahydrofuran is stirred and refluxed for 2 hours. 

To a stirred mixture of 140 parts nitric acid (d = 1.37), 1 part sodium nitrate and 240 parts water are added portionwise 89 parts dl-1-(1-phenylethyl)-2-mercapto-5-(ethoxycarbonyl)-imidazole. After the addition is complete, the whole is stirred for 2 hours at room temperature. The free base Is liberated by addition of solid sodium carbonate and the whole is extracted with 120 parts anhydrous ether while heating. The aqueous layer is separated and extracted twice with 80 parts anhydrous ether. 

To a stirred and refluxing solution of 40 parts of benzene and 35 parts of dimethylformamide (both solvents previously dried azeotropically) are added successively 1.6 parts of sodium hydride and 7.7 parts of Ct-(2,4-dichlorophenyl)imidazole-1-ethanol, (coolingon ice is necessary). After the addition is complete, stirring and refluxing is continued for 30 minutes. Then there are added 7.8 parts of 2,6-dichlorobenzyl chloride and the whole is stirred at reflux for another 3 hours. The reaction mixture is poured onto water and the product 1-[2,4-dichloro-/3 (2,6-dichlorobenzyloxy)phenethyl] imidazole, is extracted with benzene. The extract is washed twice with water, dried, filtered and evaporated in vacuo. The bese residue is dissolved in a mixture of acetone and diisopropyl ether and to this solution is added an excess of concentrated nitric acid solution. The precipitated nitrate salt is filtered off and recrystallized from a mixture of methanol and diisopropyl ether, yielding 1-[2,4-dichloro- (2,6-dichlorobenzyl-oxv)phenethyl] imidazole nitrate melting point 179°C. 

B) A mixture of 2.4 parts of 1 acetyl-4-(4-hydroxyphenyl)piperazine, 0.4 part of sodium hydride dispersion 78% 75 parts of dimethylsulfoxide and 22.5 parts of benzene is stirred for one hour at 40°C. Then there are added 4.2 parts of cis-2-(2,4-dichlorophenyl)-2-(1 H-imidazol-1 -ylmethyl)-1,3-dioxolan-4-ylmethyl methane sulfonate and stirring is continued overnight at 100°C. The reaction mixture Is cooled and diluted with water. The product is extracted with 1,1 -oxybisethane. The extract is dried, filtered and evaporated. The residue Is crystallized from 4-methyl-2-pentanone. The product is filtered off and dried, yielding 3.2 parts (59%) of cis-1-acetyl-4-[2-(2,4-dichlorophenyl)-2-(1 H-imidazol-1-ylmethyl)-13-di-oxolan-4-ylmethoxy] phenyl] piperazine MP 146°C. 

Imidazole is reacted with o -bromo-2,4-dichloroacetophenone and that product reduced with sodium borohydride. 

A suspension of 10.3 parts of the a-(2,4-dichlorophenyl)imidazole-1-ethanol thus obtained and 2.1 parts of sodium hydride in 50 parts of dry tetrahydrofuran is stirred and refluxed for 2 hours. After this reaction time, the evolution of hydrogen is ceased. Then there are added successively 60 parts dimethylformamide and 8 parts of 2,4-dichlorobenzyl chloride and stirring and refluxing are continued for another 2 hours. The tetrahydrofuran is removed at atmospheric pressure. The dimethylformamide solution Is poured onto water. 

The action of triethylamine or 4-methylmorpholine on the imidazole derivatives 1 results in the formation of 4,5-dihydro-l/f-l,2-benzodiazepines 2, which eliminate imidazole on heating with ethanolic sodium ethoxide to give H-, 2-benzodiazepines 3.121 Details for compound 3 (R1 = Ph, R2 = Me) only were reported it was stated that other derivatives were obtained similarly but details were not given. 

In general, reduction of amides to alcohols is difficult. More commonly the amide is reduced to an amine. An exception uses LiH2NBH3 to give the alcohol. Reduction with sodium metal in propanol also gives the alcohol.Acyl imidazoles are also reduced to the corresponding alcohol with NaBH4 in aqueous HC1. °... 

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