Compounds of Nitrogen and Sulphur

Some methods for introducing nitrogen substituents have already been discussed (pp. 278, 284, and 297). 

Borgna and M. Mousseron-Canet, Bull. Soc. chim, France, 1970, 2210. 

Deamination of a 20a-aminopregnane gives the 20a-ol and its acetate as major products, presumably through collapse of a stereochemically defined ion-pair, but the 20)S-amine afforded the D-homo-17a)9-ol (and its acetate) in high yield. Such rearrangements are common in the heterolysis of other 20)9-derivatives (p. 279), due to the highly favourable conformational situation. 

The 2-diazo-4,4-dimethyl-5-ene-3-one (478) is a special case, one of the main products being the l-methyl-19-nor-l(10),5-dien-3-one (480). The same product was formed when boron trifluoride reacted with the l,5-dien-3-one (479), pointing to this being an intermediate in the diazo-ketone reaction. With boron trifluoride. 

---

In addition to complex halides and cyanides, the metals form many ammines. Organic compounds of nitrogen, arsenic, sulphur, selenium and tellurium arc other possible ligands. Many complexes with bidentate ligands are known. The various types of isomerism are common thus Pd(NH3)2Cl2 occurs as the pink [Pd (NH3)4] [PdCy and as the yellow cis and trans isomers ... 

In 1986, Vojvodic and colleagues reported a study of the protective effects of a number of compounds and combinations of compounds on the toxicity of nitrogen and sulphur mustards (Vojvodic et al., 1986). Protective indices similar to those obtained by Callaway and Pearce (1958) were reported. Work on the value of thiosulphate in the treatment of mustard gas poisoning has also been reported by Fasth and Sorbo (1973). Sodium thiosulphate has been recommended as a local treatment for accidentally extravasated doses of nitrogen mustards (Dorr et al., 1988). 

Recent results in the field of catalytic oxidations with hydrogen peroxide are reviewed. Most effective catalysts fall into three categories metallorganic compounds, phase-transfer catalysts, redox zeolites. Metalloporphyrins and Pt-phosphine complexes are representative of first category. Mo and W polyoxome-talates and related systems, in association with phase transfer agents, belong to the second one. Titanium silicalite (TS-1) is the most studied redox zeolite. The oxidation of nitrogen and sulphur compounds and Fenton-like reactions are not reviewed. 

Parts 2 and 3 of the comprehensive review of the chemistry of thiazole have appearedthese include chapters on meso-ionic thiazoles and on cyanine dyes derived from thiazolium salts, and also one on selenazole and its derivatives. The chemistry of selenazole is also included in a review of selenium-nitrogen heterocycles. An account of the chemistry of thiazolidin-4-ones (which includes 2,4-diones but not rhodanine and isorhodanine) updates an earlier review. Reviews on cyclic sulphur-nitrogen compounds and on the synthesis and transformations of nitrogen- and sulphur-containing bicyclic heterocycles have appeared. More general reviews, which contain chemistry relevant to this section, cover reactions based on the onium salts of aza-aromatics, the synthesis of... 

The dienophilicity of thiet 1,1-dioxide was utilized to synthesize (73) from tetracyclone, whilst it acted also as a good dipolarophile towards diazoalkanes, giving mixtures of 1-pyrazoline derivatives (74) and (75) in which the isomers (74) predominated, except in the cases of diazomethane and diazoethane, where (75) was the major isomer. Ethyl diazoacetate on the other hand gave the 2-pyrazoline (76). These compounds arc potentially useful for the synthesis of bicyclobutanes by sequential expulsion of nitrogen and sulphur, and thermolysis or photol3rsis of (74 = R =... 

Further compounds containing nitrogen and sulphur have been isolated from accelerated sulphurations of... 

Zinc dust of good quality usually contains only negligible quantities of halogen and sulphur, and is nitrogen-free. A blank for these elements should, however, be made with every fresh batch of reagent prepared if perceptible traces of halogen or sulphur are present, a blank or control test must be performed side by side with that on the organic compound, and the results compared. 

Oxides of sulphur and other sulphur compounds Oxides of nitrogen and other nitrogen compounds Oxides of carbon... 

The simultaneous analysis of orthophosphate, glycerol phosphates, and inositol phosphates has been achieved by spectrophotometric analysis of the molybdovanadate complexes. Also, a sensitive and selective chemiluminescent molecular emission method for the estimation of phosphorus and sulphur is described, which is based on passing solutions into a cool, reducing, nitrogen-hydrogen diffusion flame. For organic compounds it was usually necessary to prepare test solutions by an oxygen-flask combustion technique. 

Acid and base extractions from this material have been shown to form spontaneous structures in solution termed coercevates that could easily form the basis for protypical membranes (more of this in Chapter 9). Hydrocarbons with chain lengths C15-C30 (both straight and branched chains) and of course PAHs, predominantly pyrene and fluoranthrene, polar hydrocarbons such as aromatic ketones, alkyl and aryl ketones, nitrogen and sulphur heterocycles and most intriguingly purine and pyrimidine analogues have all been observed from this rich carbonaceous cocktail of compounds. Why ... 

The allylic ion (XI) is probably too stable to propagate the reaction. The inhibiting (poisoning) effect of oxygen, nitrogen, and sulphur compounds is also due to formation of stable ions (in so far as it is not due to sequestration of metal halide by complex formation), e.g., the reaction [98] ... 

---