Gerard P. Moloney

Stability Studies of Oxazolidine-Based Compounds Using 1H NMR Spectroscopy

A series of oxazolidine-based compounds with a variety of substituents in positions 2 and 3 was synthesized and their stability studied. Ring opened intermediates formed on addition of limiting amounts of D(2)O to oxazolidine solutions, as observed by NMR. As the hydrolysis reactions proceeded, a series of novel dimeric beta-amino alcohol compounds formed via an internal reaction between ephedrine and the ring opened intermediates. 2-Phenyl substituted oxazolidine compounds containing electron withdrawing nitro substituents were more rapidly hydrolyzed than the unsubstituted derivative and methoxy substituted compounds, with the nitro substituents appearing to stabilize the ring opened intermediates. Two oxazolidine derivatives, with a methyl and proton at position 2, were found to be more stable to oxazolidine hydrolysis than the 2-phenyl substituted compounds. Oxazolidines incorporating phenyl substituents at position 3 were synthesized and found to be less stable than those incorporating a methyl substituent at position 3. These fundamental structure-activity relationships may be useful when choosing oxazolidine derivatives as synthetic intermediates and as prodrugs for the delivery of compounds containing either beta-amino alcohol or aldehyde components.

Synthesis and Cannabinoid Activity of a Variety of 2,3-Substituted 1-Benzo[b]thiophen Derivatives and 2,3-Substituted Benzofuran: Novel Agonists for the CB1 Receptor

An exploratory chemical effort has been undertaken to develop a novel series of compounds as selective CB1 agonists. It is hoped that compounds of this type will have clinical utility in pain control and cerebral ischaemia following stroke or traumatic head injury. We report here medicinal chemistry studies directed towards the investigation of several classes of 1-benzo[b]thiophen and benzofuran derivatives as novel CB1 agonists. We have discovered a novel series of compounds, which contain a 1-benzo[b]thiophen or a benzofuran group as the central aromatic group. Our investigation of this series of compounds has enhanced our understanding of the importance of binding sites within the CB1 receptor for favourable CB1 potency. Our understanding of these factors allowed us to modify the structure of a 1-benzothiophen derivative and improve its potency at the CB1 receptor.

1H NMR Spectroscopic Studies of the Stability of an Oxazolidine Condensation Product

Condensation of (–)‐norephedrine with excess formaldehyde under mild conditions leads to formation of the 2:1 condensation product N,N′‐methylenebis(4‐methyl‐5‐phenyl)oxazolidine compared with the reaction with 1 mol of formaldehyde, which leads to 4‐methyl‐5‐phenyloxazolidine. 1H and 13C NMR spectroscopy was used to monitor the stability of this compound and its decomposition products. The 2:1 condensation product is found to be stable in CDC13 but breaks down rapidly in CD3OD to yield a 50:50 mixture of 4‐methyl‐5‐phenyloxazolidine and 3‐hydroxymethyl‐4‐methyl‐5‐phenyloxazolidine. Upon addition of D2O to this equimolar mixture, the latter compound decomposes to norephedrine and formaldehyde, whereas the former compound is stable.