Novel synthesis

A novel synthesis of 2-thiazolecarboxaldehyde uses the reaction of 2-thiazolyUithium with N-methylformanilide with a yield of 46% (99). Similarly, 5-thiazolecarboxaldehyde was obtained in 5% yield, the poor yield probably being a result of the low stability of 5-thiazolyllithium. These unsatisfactory yields led Iversen and Lund to investigate four new methods (97). 

The most widely used industrial synthesis of phenol is based on isopropylbenzene (cumene) as the starting material and is shown m the third entry of Table 24 3 The eco nomically attractive features of this process are its use of cheap reagents (oxygen and sulfuric acid) and the fact that it yields two high volume industrial chemicals phenol and acetone The mechanism of this novel synthesis forms the basis of Problem 24 29 at the end of this chapter... 

Methylene thiirane is obtained by thermolysis of several spirothiirane derivatives which are formally Diels-Alder adducts of methylenethiirane and cyclopentadiene or anthracene <78JA7436). They were prepared via lithio-2-(methylthio)-l,3-oxazolines (c/. Scheme 121). A novel synthesis of the allene episulfide derivatives, 2-isopropylidene-3,3- dimethylthiirane (good yield) or its 5-oxide (poor yield), involves irradiation of 2,2,3,3-tetramethyl-cyclopropanethione or its 5-oxide (81AG293). Substituents on the thiirane ring may be modified to give new thiiranes (Section 5.06.3.9). The synthesis of thiirane 1-oxides and thiirane 1,1-dioxides by oxidation is discussed in Section 5.06.3.3.8 and the synthesis of 5-alkylthiiranium salts by alkylation of thiiranes is discussed in Section 5.06.3.3.4. Thiirene 1-oxides and 1,1-dioxides may be obtained by dehydrohalogenation of 2-halothiirane 1-oxides and 1,1-dioxides (Section 5.06.4.1.2). 

A novel synthesis of nornicotyrine has been described by Lions and Ritchie, who condensed ethyl nicotinylacetate hydrochloride with a -dichlorodiethyl ether in presence of ammonia at — 10° to — 13° and then at room temperature, producing mainly ethyl 2-(3 -pyridyl)furan-3-carboxylate, but also some ethyl 2-(3 -pyridyl)pyrrole-3-carboxylate,... 

The use of 2,5-dimethoxytetrahydrofuran (20) as a succinaldehyde equivalent has expanded the PK synthesis to include unsubstituted pyrroles, for example, 21. A novel synthesis of monosubstituted succinaldehydes is also available for the PK pyrrole synthesis. ... 

Prior to the 1947 report by Cook and Heilbron on their novel synthesis, 5-aminothiazoles were mostly unknown in the literature. Previous syntheses included the Curtius degradation of ethyl thiazole-5-carboxylates which did not have general applicability there was also difficultly in obtaining the necessary starting materials. During a study on penicillin, Cook and Heilbron found that the reaction between methyl dithiophenylacetate and ethyl aminocyanoacetate gave what was initially believed to be ethyl phenylthionacetamidocyanoacetate 4. However further studies proved the compound to be 5-amino-4-carbethoxy-2-benzyl-thiazole 5, which was basic. 

A novel synthesis of 2-aminoquinoxalin-3-one 1-oxide has been effected by the hydrogenation of o-nitro-l-cyanoformanilide in ethanol in the presence of Adam s catalyst.- ... 

Recently, the pyrazole group containing bisphenols have been synthesized from activated aromatic dihalides and 3,5-bis (4-hydroxy phenyl)-4-phenyl pyrazole or 3,5-bis(4-hydroxy phenyl)-1,4-diphenyl pyrazole. A novel synthesis of imido aryl containing bisphenols has been reported [32]. N-substituted l,4-bis(4-hydroxy phenyl)-2,3-naphthalimides were prepared from phenolphthalein and copolymerized with aromatic sulfone or ketone difluorides to obtain the poly(imidoaryl ether) sulfones/ ketones. 

See M. Alajarin, R.-A. Orenes, A. Vidal, A. Pastor, Synthesis 2003, 49 for a novel synthesis of non-chiral azirines. 

A novel synthesis of optically active l-mcthyl-2-butenylboronate 4 has been achieved by... 

Wefero-Dlels-Alder reactions of 3,5-di-fe/-f-butyl-o-benzoquinone with acyclic dienes novel synthesis of 1,4-benzodioxanes [135]... 

Wu K, Yang JY, Konak C et al (2008) Novel synthesis of hpma copolymers containing peptide grafts and their self-assembly into hybrid hydrogels. Macromol Chem Phys 209 467 75... 

Fernandez, E.J., Gimeno, M.C., Jones, P.G., Laguna, A. and Olmos, E. (1997) Strong Activation of the Double Bond in (PPh2)2C CH2. Novel Synthesis of Gold (111) Methanide Complexes by Michael Addition Reactions. Organometallics, 16 (6), 1130-1136. 

Wada, M., Sakurai, Y., Akiba, K.-y. (1984) Addition of Alkynyl Anions to Aldimines Containing A-Hydrogens A Novel Synthesis offi-Aminoacetylenes. Tetrahedron Letters, 25, 1083-1084. 

Among various methods to synthesize nanometer-sized particles [1-3], the liquid-phase reduction method as the novel synthesis method of metallic nanoparticles is one of the easiest procedures, since nanoparticles can be directly obtained from various precursor compounds soluble in a solvent [4], It has been reported that the synthesis of Ni nanoparticles with a diameter from 5 to lOnm and an amorphous-like structure by using this method and the promotion effect of Zn addition to Ni nanoparticles on the catalytic activity for 1-octene hydrogenation [4]. However, unsupported particles were found rather unstable because of its high surface activity to cause tremendous aggregation [5]. In order to solve this problem, their selective deposition onto support particles, such as metal oxides, has been investigated, and also their catalytic activities have been studied. 

Zanarotti, A. Preparation and reactivity of 2,6-dimethoxy-4-allylidene-2,5-cyclohexa-dien-l-one (vinyl quinone methide). A novel synthesis of sinapyl alcohol. Tetrahedron Lett, 1982, 23, 3815-3818. 

For conversion of amide to other acid derivatives, a novel synthesis of urea glycosides in aqueous media has been reported via the reaction of Steyermark s glucosyl carbamate with amines in good yields (Eq. 9.17).38 This method was successfully applied to develop a new route to the synthesis of urea-tethered neo-glycoconjugates and pseudooligosaccharides. 

A recently discovered novel synthesis of toluenebenzylsulfoxides is based on the reaction of AT-phenylacetylbenzotriazoles with sodium toluenesulfinates [27a]... 

A novel synthesis of a germanimine involves the reaction between germane and CF3NO.36 The N-trifluoromethylgermanimine was subsequently treated with (CF3)2NO to give the mono- and the bis[bis(trifluoromethyl) nitroxy]-substituted derivatives. These derivatives were subsequently treated with hydrogen chloride to give the mono- or the dichloro derivatives, respectively. 

A review9 with more than 37 references includes an examination of symmetry groups and chirality conditions for C60 and C70 bonded to one or two metals in rf and/or rf fashion. Palladium and platinum rf complexes of C6o and C70 are described (novel synthesis, NMR spectra, electrochemistry) as well as first optically active organometallic fullerene derivatives. 

Schaefer and Honig146 and reported it as a novel synthesis of 2-oxaadaman-tanes, where the treatment of 105a with concentrated sulfuric acid afforded 104 in 35-40% yields. 

The novel synthesis of chromanocoumarans illustrated in Scheme 159 constitutes a modification of the Heck arylation process (cf. Eq. 14 in Section IV,B,1) in which arylation of a 2H-chroman is followed by intramolecular nucleophilic displacement of the palladium moiety.235... 

A novel synthesis of iodothiazole 38 takes advantage of Wiemer s protocol for the synthesis of vinyl iodides from ketones <06JOC5031>. The thiazolyl phosphate 37, prepared from 2-isopropylaminothiazoline-4-one 36, is converted to the desired iodothiazole 38 upon treatment with in situ generated trimethylsilyl iodide. This iodide is a key intermediate in the synthesis of the quinolone substructure of the protease inhibitor BILN 2061. 

A novel synthesis of alkylsulfanylisothiazoles 230 starts with sodium a-cyanoketene dithiolates 227, obtained by the reaction of cyanoacetamides 226 with carbon disulfide in the presence of sodium ethoxide <06SC825>. Treatment of 227 with sulphur and piperidine acetate generates sodium isothiazole-3,5-dithiolates 229. The formation of 229 is assumed to arise from the addition of anionic sulphur to the nitrile group in 227 to give the intermediate 228, which cyclizes upon elimination of anionic sulphur to yield 229. Salts 229 are readily alkylated to furnish 3,5-bis(alkylthio)isothiazole derivatives 230. 

A novel synthesis of isothiazolidines involves sulfonium ylides, formed by the reaction of thietanes and nitrenes <06TL1109>. Exposure of A-(/ -tolylsulfonyl)imino)phenyliodinane 232 with excess of thietanes 231 (5 equiv) in the presence of a catalytic amount of Cu(II)... 

A novel synthesis of 1,2,3-selenadiazoles 338 starts with the Michael addition of 2-nitropropane to a,P-unsaturated ketones 336 under basic conditions <06JHC149>. The resulting adducts are treated with semicarbazide hydrochloride to give semicarbazones 337, which are converted to 1,2,3-selenadiazoles 338 by reaction with selenium dioxide in THF (the choice of the solvent appears to be important in this case). 

The synthesis of (V-heterocyclic isothiocyanates has been a difficult challenge due to their propensity to oligomerize by autocatalysis. In an attempt to alleviate this issue, silver thiocyanate was used in a novel synthesis of 4-quinolyl isothiocyantes <06TL2161>. Reaction of 4-chloroquinoline with silver thiocyanate in refluxing anhydrous toluene for 12 h results in the desired product in quantitative yields and excellent purity. 

Another novel synthesis of phenazines was introduced by Vagg and co-workers <00JHC151>. The key step was the reaction of dicarboxylic acid 230 with various 1,2-diamines to give 231, 232, and 233. Each was a potential polydentate ligand capable of interacting with DNA via their extended phenanthroline or phenazine components. 

A novel synthesis of D-glucose 6-phosphate (in 55% yield) has been reported it involves alcoholysis of the cyclic phosphate of catechol with 1,2-O-isopropylidene-a-D-glucofuranose, followed by acid hydrolysis of the so-formed phosphoric diester.192 The reagent... 

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