Abstract
The synthesis of the thiazolo -, thiazin - and thiazepino- quinazolinones (A)-(C) was achieved, by the condensation of anthranilic acid with appropriate sulphur containing lactams, in the presence of phosphoryl chloride. The quinazolinones (A) and (B) were shown to react (at the methylene group alpha to the carbon-nitrogen double bond) with a variety of electrophiles at elevated temperatures. Compound (C) was found to be inert to electrophiles under the same reaction conditions.The ability of the heterocycles (A)-(C)to react with heterocumulenes, following deprotonation with sodium hydride in DMSO, was demonstrated. Reaction of the anion derived from (B) with alkylating agents, Michael acceptors and activated halopyridines afforded novel substituted derivatives. The oxidation, Pummerer rearrangement and deacetylation of (A)-(C) was accomplished to yield analogues which were similar in structure to the biologically active compound vasicinone. A series of C-ring substituted analogues of (A) were prepared and the sulphoxides derived from these compounds subjected to Pummerer rearrangement.
(A) and (B) were oxidatively ring opened on treatment with excess peracetic acid, whilst under similar reaction conditions (C) gave a sulphone. Investigations in to the reduction of substituted derivatives of (B) led to the novel tetracyclic compound (D).
| Date of Award | Jan 1989 |
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| Original language | English |
| Awarding Institution |
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| Supervisor | A. D. Dunn (Supervisor) |