Preparation from compounds containing

Carboxylic acids could be prepared from compounds containing an active hydrogen atom with dry carbon dioxide in the presence of 2-12 mol equiv. of DBU at ambient temperature in dimethylformamide or dimethyl sulfoxide, or without solvent (74CL427 77JAP(K)202). The yields of the carboxylic acids increased with the pressure of carbon dioxide (77JAP(K)202). 

Epoxy di(meth)acrylates (also caUed vinyl esters) are another name for the p-hydroxyester acrylates, because they are usuaUy obtained by reacting epoxy resins of glycidyl derivatives with (meth)acrylic acid. They can also be manufactured from bisphenol A and glycidyl (meth)acrylates. Although prepared from compounds containing reactive epoxy groups, completed epoxy di(meth)acrylate molecules do not contain these groups. Both aromatic and aliphatic epoxy di(meth)acrylates are available, as weU as acrylated epoxydised oUs (Jolanki 1991 Jolanki et al. 1995). 

PROBLEM 3 Describe how the following compounds could be prepared from compounds containing no more than six carbons. (You can also use triphenylphosphine.)... 

The versatility of lithium aluminum hydride permits synthesis of alkyl, alkenyl, and arylsilanes. Silanes containing functional groups, such as chloro, amino, and alkoxyl in the organic substituents, can also be prepared. Mixed compounds containing both SiCl and SiH cannot be prepared from organopolyhalosilanes using lithium aluminum hydride. Reduction is invariably complete. 

A somewhat different approach is used to prepare the compounds containing the amine at the 4 position. Condensation of the amidine from acetonitrile (138) with the enol ether from formylacetonitrile (137) leads to the requisite pyrimidine (139). 

In an alternate approach to the preparation of compounds containing the additional ring, haloamide, 41 (obtained from the aminobenzophenone and bromoacetylbromide) is alkylated with etha-nolamine to afford 42. Treatment of the amino alcohol in acetic acid affords the carbonyl addition product, 43, at the same time... 

This preparation describes a convenient and general method of synthesis of substituted pyrimidines from compounds containing a /3-dicarbonyl group, either intact or as the corresponding ketal. The usefulness of the 2-mercaptopyrimidines is enhanced by the ease of removal of the mercapto group by desulfurization 9 or oxidation 10 and its replacement by other functional groups.1 ... 

The oxidation-resistant SiC fiber was prepared from polycarbosilane containing Zr(OC4H9)4 by the same process as that used for the aforementioned tita-nia/silica fiber, except that the calcination was performed in Ar atmosphere at 1400 °C. In this case, the polycarbosilane and Zr(OC4H9)4 were effectively converted into SiC-based bulk ceramic and zirconium oxide (cubic zirconia). Before the conversion, bleed-out of the zirconium compound proceeded effectively. AES depth analysis of the fiber surface showed an increase in the concentration of zirconium towards the surface. This construction was confirmed by the TEM image of the cross-section near the fiber surface. This indicates the direct production of a SiC-based fiber covered with a Zr02 surface layer, which... 

RCu(CN)ZnI.u These new copper reagents are prepared by reaction of primary or secondary iodides with zinc that has been activated with 1,2-dibromoethane and chlorotrimethylsilane. The resulting organozinc compounds are then allowed to react with the THF-soluble CuCN-2LiCl (equation I). Because of the mild conditions, these new reagents can be prepared from iodides containing keto, ester, and nitrile groups. 

A variety of cyclic products have been prepared from educts containing carbonyl as well as carboxylic groups. Thus, Hanusch-Kompa and Ugi prepared a large number of five-membered cyclic gamma-lactam compounds like 44 from levulinic acid. Other carbonylic acids can lead to compounds like 45, which is made from phthalaldehyde acid, valine methylester, and tert-butylisocyanide. The products like 46 and 47 can result from the U-4CR and further cyclization. 

One alternative approach is to use photoisomerisable chiral compounds where the E and Z isomers have different helical twisting powers, e.g. menthone derivatives. By incorporating co-polymers, prepared from menthone containing monomers and cyano esters (5.5), as dopants into nematic LC mixtures materials, e.g. a mixture of cyanobiphenyls and cyanoterphenyls (E7 available from Merck), colour change can be effected by irradiating with UV light (365 nm). The colour obtained is dependent... 

Epoxy resins are usually prepared from compounds (or polymers) containing two or more epoxy groups that have been reacted with amines, anhydrides, or other groups capable of opening the epoxy ring and forming thermosetting products. Polymers from monoepoxy compounds have already been described in Sandler and Karo [1]. 

The oxidation of chars prepared from nitrogen-containing precursors has been investigated. Chars produced from the nitrogen-containing compounds acridine and phenanthridine were oxidized at atmospheric pressure at temperatures of 773-873 K. The relative rates of nitrogen and carbon release and the formation of NO have been determined in relation to char nitrogen content and precursor type. 

Granular anion-exchange resins have been prepared from N-containing C-vinyl heterocyclics, polyvinyl compounds and one or more aliphatic vinyl compounds in an aqueous phase in presence of water-insoluble suspension stabilizers Thus, a mixture of 4-vinylpyridine, ethylacrylate, and p-DVB on polymerization using hydroxylapatite as suspension stabilizer and AIBN as the initiator gives an anion-exchange resin. 

The preparation of compounds containing nitrogen double bonded to another heteroatom has been accomplished by a rDA pathway. Cis- and (rnns-azomethane have been synthesized from tetrahydropyrida-zine (171) by thermal retrodiene extrusion (equation 77). The anti conformation of (171) is presumed to give (rnns-azomethane and the syn conformations yields the cis-isomer. Preparation of nitrosyl hydride (173) has been accomplished under mild nonphotochemical conditions, unlike conditions used in previous preparations. The extrusion of nitrosyl hydride from anthracene adduct (172) as shown in equation (78), which occurs at a very mild temperature, was followed by microwave detection of (173). 

Compounds Prepared from Phosphorus - Containing Aldehydes and Ketones... 

SAR studies were performed on compoimds containing the 9H-isothia-zolo[5,4-fc]quinoline-3,4-dione (ITQ) nucleus and it was found that some of them are potent antibacterial agents (see Scheme 101) [114,115]. They were prepared from compound 353, which was treated with cyclopropyl isothiocyanate in DMF and then with Mel. Compound 354 (94%) was obtained and treated with in NaH in DMF to give the isothiazolo[ 5,4-fo] quinoline compound 355 (93%). Its treatment with anhydrous NaSH gave the corresponding mercaptan (84%), which was directly cychsed without purification to 356 (85%) in the presence of hydroxylamine-O-sulfonic acid. Microwave-assisted Suzuki-Miyaura cross-coupling of the ITQ nucleus 356 with the desired aryl-boronic esters or acids afforded derivatives 357, typically, in 30-50% yield after HPLC purification (Scheme 87). 

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