No description available.

No description available.

No description available.

Thesis (M.Sc.) -- University of Adelaide, Dept. of Organic Chemistry, 1972.

No description available.

No description available.

Through NMR experiments of the reaction of barbituric acid with carbodiimide, a general synthetic procedure for the preparation of 5-diaminomethylenebarbiturates (DABA) was developed. This procedure is very simple and applicable to the preparation of large quantities of DABA derivatives. Through the X-ray structural study of one of the DABA derivatives it was established that these compounds have a ylide-type structure with strong charge separation inside the molecule. 5-Ylide-pyridinium-methyl barbituric acid derivatives were investigated with the isolation of 4-dimethylamino-1-(2,4,6-trioxohexahydro- pyrimidin-5-ylide-methyl)-pyridinium as well as its corresponding 1,3- dimethylbarbituric acid derivative with quantitative yields. An alternative approach was attempted in order to prepare chiral 5-ylide-pyridinium-methyl-barbituric acid derivatives thus containing a chiral center between the charge separation. The extreme instability of the derivatives under investigation afforded the unique isolation of 4-dimethylamino-1- [(1,3-dimethyl-2,4,6-trioxo-hexahydro-pyrimidin-5-yl)-phenyl-methyl]-pyridinium in quantitative yield.

Thesis (Ph. D.)--Oregon Graduate Center, 1978.

Ph.D. / Organic Chemistry / Synthesis of sulfonium ylids, 3-dimethylsulfonioindolide, 3-dimethylsulfonio- 2-methylindolide and 3-dimethylsulfonio-2-phenylindolide were accomplished. Carbon-13.and [superscript 1] H nmr of ylids and the related thioethers and sulfonium salts were studied in an attempt to describe the electronic changes occurring within the indole system to accommodate ylid stabilization. In a study of their physical properties, it was discovered that the sulfonium salt <===> ylid system displayed a hysteresis during acid - base titration. The cause for the hysteresis was shown to be a result of covalent hydration (probably of the indole C2-C3 double bond). The uv spectra of the ylid and its analogs differed in aqueous and nonaqueous solvents suggesting that a chemical reaction occurred in protic solution. The [superscript 1] H nmr of sulfonium salts in protic solvents revealed the formation of a new species in the solution. This new species, upon acid - base titration exhibited a titration hysteresis identical to that previously observed in titration of either sulfonium salt or ylid. The mass spectra of the sulfonium salts and ylids by different techniques (EI, EI with rapid sample heating and FD) were obtained; by the newly developed technique of electron ionization with rapid heating and photoplate ion recording, indole sulfonium salt "hydrates" exhibit ions assignable as sulfonium salt hydrate species.

Thesis (Ph. D.)--University of California, Riverside, 2009. / Includes abstract. Title from first page of PDF file (viewed Mar. 8, 2010). Includes bibliographical references. Issued in print and online. Available via ProQuest Digital Dissertations.