Abstract
Sodium fomaldehyde sulphoxylate is a reducing reagent which has been used widely in the paper and textile industries, but its use as a reagent for organic synthesis has been little explored until now. This thesis describes several novel applications of the use of sodium formaldehyde sulphoxylate to organic synthesis.The reductive dehalogenation of a-halo carbonyl compounds and the reductive desulphonation of acyl sulphones are important reactions in synthesis but there are few convenient reagents available for carrying them out on a large scale. Most of the reported methods use expensive, toxic or harzardous reagents. An investigation was performed into the use of sodium formaldehyde sulphoxylate for reductive dehalogentation and it was demonstrated that the reagent can be used in ethanol or DMF as solvent. For example phenacyl chloride was reduced to acetophenone in high yield in ethanol after 1h at reflux. The reagent is not useful for the reductive desulphonation reaction, however, it has been shown that sodium dithionite can be used for this reaction.
Dibenzyl sulphones can be prepared from benzyl halides using sodium dithionite in low yield. An investigation into the formation of dibenzyl sulphones using sodium formaldehyde sulphoxylate has been performed. Moderate yields of sulphones are obtained when DMF is used as solvent.
It was thought that since sodium formaldehyde sulphoxylate is a mild reducing agent it may find applicability in the selective reduction of aldehydes in the presence of other functionalities. This has been shown to be the case, with only aromatic aldehydes with electron donating groups in the ring, and benzils, readily reduced by the reagent. Other ketones, nitriles and acides are unaffected, or only very slowly reduced, by the reagent.
In all it has been demonstrated that sodium formaldehyde sulphoxylate is a potentially useful reagent for organic chemistry, being inexpensive and not hazardous to use.
| Date of Award | 1989 |
|---|---|
| Original language | English |
| Supervisor | Timothy Mason (Supervisor) |