John P. James

Synthesis and antispasmodic activity of nature identical substituted indanes and analogues

Abstract The synthesis of a series of substituted indanes which provide routes to nature-identical compounds and their analogues is reported. The smooth muscle relaxant activity of a series of substituted indanes and indanones together with their analogues has been measured. A compound with significant smooth muscle relaxant activity has been identified.

Azapropellanes: new fused tetra-azatriazolo[n.3.3.01,x]-dodecenes and tridecenes. Substituted 3,3a,4,5,6,6a-hexahydropyrrolo[2,3-d]-1,2,3-triazoles from a general tandem cycloaddition–rearrangement reaction of 1,2,3-triazolium imides with substituted alkenes: kinetics and mechanism: azolium 1,3-dipoles. Part 3

Reactions of substituted 1,2,3-triazolium-1-imide 1,3-dipoles with a range of substituted alkene and alkyne dipolarophiles gave rise to derivatives of the new ring systems hexahydropyrrolo[2,3-d]-1,2,3-triazoles and the azapropellanes tetra-aza-tricyclo[5.3.3.01,7]tridecenes and -tricyclo[4.3.3.01,6]dodecenes. The reactions, which are regio- and stereo-specific, are shown to be tandem 1,3-dipolar (endo) cycloadditions and sigmatropic rearrangements. X-Ray crystal structures of 6exo-ethoxycarbonyl-2,3a,4,6a-tetraphenyl-3,3a,4,5,6,6a-hexahydropyrrolo[2,3-d]-1,2,3-triazol-2-ium-3-ide (9a) and 12exo-cyano-8,10-diphenyl-7,8,9,10-tetra-azatricyclo[4.3.3.01,6]dodec-7-en-8-ium-9-ide (4a; m= 2) are reported.

Inter- and intra- molecular cyclisation reactions of azoacetates derived from aryl hydrazones of ethyl acetoacetate and acetoacetanilides

The base induced cyclisations of azoacetates to azetidinones were investigated. In addition to the isolation of the desired products, it was found that 2-iminopyrrolidine-5-one derivatives as well as N-acyl hydrazides could be isolated when metal cyanides were employed as base. These entities were further modified to form pyrrolidine-2,5-diones and diazetidinones respectively.

Photochemical transformations of cyclic azimines–X-ray crystallographic analysis of intermediates in their sequential phototransformations

A series of sequential transformations on irradiation of the readily available cyclic azimines 2 lead to saturated pyrrolo[2,3-b]indoles 3, the mechanism of which is confirmed by isolation of photolabile intermediates 4 and 7 and two crystallographic determinations.

Synthesis, characterisation and variable-temperature nuclear magnetic resonance of bis(bipyridine)ruthenium complexes containing dihydrazone ligands

A series of dihydrazone and substituted dihydrazone derivatives of biacetyl and of hydrazone and phenylhydrazone derivatives of 2-acetylpyridine bind to [Ru(bipy)2Cl2] to give [Ru(bipy)2(L–L)][PF6]2 complexes {bipy = 2,2′-bipyridine; L–L = biacetyl di(phenylhydrazone)1a, biacetyl di[methyl(phenyl)hydrazone]1b, biacetyl di(o-tolylhydrazone)1c, biacetyl di(dimethylhydrazone)1d, biacetyl dihydrazone 1e, biacetyl di(benzaldehyde azine)1f, 2-acetylpyridine phenylhydrazone 1g, or 2-acetylpyridine hydrazone 1h}. The structures of all complexes have been determined using IR, UV/VIS, NMR and microanalysis. The proton NMR spectra of 1a–1c show an unusual dependence on probe temperature with broadened aromatic resonances, sharpening at both high and low temperature in the case of 1b and 1c. No emission was observed for complexes with two hydrazone moieties, whereas it was observed for 1g and 1h with one hydrazone. The molecular structure of 1a has been determined and shows a hydrazone phenyl group lying over each of the bipyridyl rings: space group C2/c, a= 25.895(3), b= 10.505(1), c= 17.431(2)A, β= 106.03(2)° and Z= 4.

Azoacetates as synthons for the azetidinone and diazetidinone ring systems

The azoacetates derived from aryl hydrazones of α,α-disubstituted-β-ketoamides are readily transformed into azetidinones or diazetidinones.

Reactions of mercury(II) acetate with nitrogen compounds. Part 9. Oxidations of the bis-(4-nitrophenylhydrazone)s of some 1,3-diketones with mercury(II) acetate and lead(IV) acetate

Oxidation of bis-(4-nitrophenylhydrazone)s of 1,3-diketones containing an α-CH between the hydrazone chains resulted in cyclisation with fragmentation, giving pyrazoles. The reaction is considered to involve dehydrogenation of the conjugated tautomeric enamine form of the bis-hydrazone, giving a cis-azo-hydrazonoalkene intermediate. When the postulated azo-hydrazonoalkene intermediate had trans-stereochemistry, unfavourable for cyclisation, as in the oxidation of cyclohexa-1,3-dione bis-(4-nitrophenylhydrazone), the azo-alkene was stable and was the main product. When the conjugated enamine tautomeric form of the 1,3-bis-hydrazone could not exist, as with 3,3-dimethylpentane-2,4-dione bis-(4-nitrophenylhydrazone), pyrazoles were not formed and the hydrazone chains behaved as isolated monohydrazones.