Aqueous reactions glycols

Of greater versatility is an extension of Albert and Royer s acridine synthesis. The first successful use of this in the quinazoline series was for the removal of the chlorine atom in 2-chloro-4-phenylquin-azoline, although it had been used previously to prepare 8-nitro-6-methoxyquinazoline in very poor yield. The 4-chloroquinazoline is converted to its 4-(A -toluene-p-sulfonylhydrazino) quinazoline hydrochloride derivative which is decomposed with alkali in aqueous ethylene glycol at lOO C (Scheme 13). The yields are high (60-70%) when R is Me, Cl, OMe but low when R is NO2, and in the latter case it is preferable to use dilute sodium carbonate as the base. This reaction is unsatisfactory if the unsubstituted pyrimidine ring is unstable towards alkali, as in 1,3,8-triazanaphthalene where the pyrimi-... 

Pb(C2H303)2 (aq.). de Forcrand3 measured the heat of reaction of aqueous lead glycollate with aqueous hydrogen sulfide to be 11.5. 

Perbenzoic acid is an important reagent for the preparation of epoxides from olefinic compounds (method 126). When the epoxides are unstable in aqueous solution, glycols ate formed directly. The over-all reaction results in trans addition of hydrcscy groups to the double bond for crotonic and isocrotonic acids. ... 

Hydrolysh-deearboxylation. The Organic Syntheses procedure for the conversion of diethyl 2,5-diketocyclohexane-l,4-dicarboxylate (I) to cyclohexane-1,4 iione (2) calls for treatment with water in a steel autoclave at 185 195° for 1015 min. (yield 72-80%). The reaction can be carried out more conveniently and in higher yield by refluxing in aqueous ethylene glycol containing some p-toluenesulfonic acid. ... 

The cationic palladium(II) complex [Pd(24a)3Cl]+ of the para-isomer of 24a (M = Na) catalyzes the carbonylation of benzyl chloride in basic medium to give phenyl-acetic acid in high yields. The Pd(0) complex [Pd(24a)3], formed by reduction of [Pd(24a)3Cl]+ with CO, is asumed to be the catalytic species [93] (see Scheme 1). Palladium complexes of ligands related to 24a (M = Na) have also been employed in aqueous ethylene glycol phases as catalysts for Suzuki-type C—C cross-coupling reactions for the syntheses of substituted biphenyls (cf. Section 6.6) [97]. 

Preparation of 1-[L-(-)-y-Benzyloxycarbonylamino-ot-Hydroxybutyryl]-6 -Carbobemoxy-kanamycin A A solution of 1.6 grams (4.6 mmol) of L-(-)-7-benzyloxycarbonylamino-a-hydroxybutyric acid in 40 ml of ethylene glycol dimethyl ether (DME) was added drop-wise to a stirred solution of 2.6 grams (4.2 mmol) of 6 -monobenzyloxycarbonylkana-mycin A in 40 ml of 50% aqueous ethylene glycol dimethyl ether and the mixture was Stirred overnight. The reaction mixture was evaporated under reduced pressure to give a brown residue 1-[L-(-)-7-benzyloxycarbonylamino-cr-hydroxybutyryl]-6 -carbobenzoxykana-mycin A which was used for the next reaction without further purification. 

The copper-catalyzed N-arylation of sulfoximines was realized in aqueous polyethylene glycol at room temperature acceleration in an ultrasound bath resulted in excellent yields within 10 min reaction time [113]. A one-pot synthesis of triazoles was accomplished under similar conditirais by arylation of sodium azide followed by click coupling with terminal alkynes [114]. 

Viscosity. The reaction between ferroprotoporphyrin IX and carbon monoxide is diffusion controlled in glycerol, but is under normal chemical activation control in aqueous ethylene glycol, as mentioned in the previous Volume of this Report. The balance between the two modes of control of activation has now been investigated for a range of glycerol-water mixtures over a range of temperatures, in other words... 

Also obtained by reaction of 2-hydroxy-5-nitrobenzaldehyde with iodobenzene by using a catalyst system of palladium chloride/lithium chloride in the presence of sodium carbonate in N,N-di-methylfonnamide at 120° for 22 h (58%) [51], Preparation by dealkylation of 2-(2-hydroxyethoxy)-5-nitrobenzophenone (SM) in methylene chloride with boron tribromide at r.t. for 18 h (94%) [523], SM was obtained by reaction of potassium hydroxide with 2-chloro-5-nitrobenzophe-none in refluxing aqueous ethylene glycol (135°) for 6 h (65%). 

The preparation of a-hydroxyphosphonates in a mixture of water and polyethylene glycol has been reported (Scheme 4.144) [183]. The chemistry was operationally trivial and involved simply stirring the reagents in the solvent mixture at room temperature. These aqueous reactions generated moderate to excellent yields of the compounds. The method was tolerant of a variety of functional groups including nitro, amino, and an unprotected phenol. Heteroarenes such as imidazole were also successfully functionalized. As with many related reactions, ketones were unreactive under the reaction conditions. This approach is one of the most practical syntheses of a-hydroxyphosphonates due to the simplicity of the reaction and the ability to promote the reaction in water at room temperature. 

The reaction represented is that with hydrazine solution, produced from hydrazine sulphate and sodium acetate in the presence of aqueous alcohol. Excellent results are also obtained by interaction of the commercially available 60-64 per cent, hydrazine solution with a solution of 2 4 dinitrochloro-benzene in triethylene glycol or in diethylene glycol at about 20°. 

Another method for the hydroxylation of the etliylenic linkage consists in treatment of the alkene with osmium tetroxide in an inert solvent (ether or dioxan) at room temperature for several days an osmic ester is formed which either precipitates from the reaction mixture or may be isolated by evaporation of the solvent. Hydrolysis of the osmic ester in a reducing medium (in the presence of alkaline formaldehyde or of aqueous-alcoholic sodium sulphite) gives the 1 2-glycol and osmium. The glycol has the cis structure it is probably derived from the cyclic osmic ester ... 

Acetals andKetals. Acetals of 1,3-diols are prepared by refluxing the diol with the aldehyde in the presence of an acid catalyst, even in an aqueous medium. The corresponding ketals are more difficult to prepare in aqueous solution, but cycHc ketals of neopentyl glycol, eg, 2-butyl-2-ethyl-5,5-dimethyl-l,3-dioxane (3), can be prepared if the water of reaction is removed azeotropicaHy (34). 

Ethynylation. Base-catalyzed addition of acetylene to carbonyl compounds to form -yn-ols and -yn-glycols (see Acetylene-DERIVED chemicals) is a general and versatile reaction for the production of many commercially useful products. Finely divided KOH can be used in organic solvents or Hquid ammonia. The latter system is widely used for the production of pharmaceuticals and perfumes. The primary commercial appHcation of ethynylation is in the production of 2-butyne-l,4-diol from acetylene and formaldehyde using supported copper acetyHde as catalyst in an aqueous Hquid-fiHed system. 

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