The article contains sections titled: 1. Introduction 2. Pyridine and Alkylpyridines 2.1. Properties 2.2. Production 2.2.1. Separation from Tar 2.2.2. Synthesis from Aldehydes or Ketones with Ammonia 2.2.3. Synthesis from Acrylonitrile and Ketones 2.2.4. Synthesis from Dinitriles 2.2.5. Dealkylation of Alkylpyridines 2.2.6. Synthesis of 5‐Ethyl‐2‐Methylpyridine from Paraldehyde and Ammonia 2.2.7. Synthesis from Nitriles and Acetylene 2.2.8. Other Synthetic Methods 2.3. Quality Specifications, Storage, and Transportation 2.4. Uses 2.5. Economic Aspects 3. Pyridine Derivatives 3.1. Vinylpyridines 3.2. Bipyridines 3.3. Quaternary Pyridinium Salts 3.4. Pyridine N ‐Oxides 3.5. Piperidines 3.6. Halopyridines 3.7. Pyridinecarbonitriles, Carboxylic Acids, and Carboxamides 3.8. Aminopyridines 3.8.1. 2‐Aminopyridine 3.8.2. Other Aminopyridines 3.9. Pyridinols 3.10. Pyridyl Alcohols 3.11. Pyridinecarbaldehydes 3.12. Pharmaceuticals and Agrochemicals 4. Toxicology 4.1. Acute Toxicity 4.2. Subacute and Chronic Toxicity 4.3. Mutagenicity and Ecotoxicity

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The reaction of primary and secondary alkyl halides with mercury(II) acetate in oxiranes, oxetanes, and tetrahydropyran results in ring-opening to give the corresponding alkoxyalkyl acetates. Similar reactions with mercury(II) thiocyanate in oxetanes afford alkoxyalkyl isothiocyanate and thiocyanate, ROCH2C(R′)2CH2NCS and ROCH2C(R′)2CH2SCN, where the isomer ratios (N/S ratios) are 82–96/4–18. It is suggested that the reactions involve the initial formation of a three-, four-, or six-membered O-alkyloxonium ion intermediate and subsequent attack by XHgZ2−.

Treatment of olefins with a mixture of iodine and mercury(II) thiocyanate in benzene or diethyl ether gives vic-iodo(isothiocyanato)alkanes and vic-iodo(thiocyanato)alkanes in a high yield, the former being predominant. Similar results were obtained by using silver(I) and thallium(I) thiocyanates, though both the yield and the selectivity are slightly lower. By use of potassium thiocyanate and copper(I) isothiocyanate in place of mercury(II) thiocyanate, β-iodo thiocyanates were mainly formed. A reaction scheme involving initial formation of an iodonium ion from olefin and ISCN (formed in situ) and a subsequent attack of complex anion I(SCN)2− has been proposed to account for this predominant formation of β-iodo isothiocyanates.

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