Sulfur-nitrogen compounds acid salts

A number of nitrogen- and sulfur-containing heterocyclic compounds are effective corrosion inhibitors (62MI11502), the imidazolines and the benzotriazoles being particularly important types. The imidazolines are derived from ethyleneamines by reaction with fatty acids the free bases (53), the fatty acid salts (54), and various derivatives obtained by reaction with anhydrides, isocyanates or alkyl halides (55) are effective inhibitors. 

The flavor of fish and seafoods is composed of taste-active low molecular-weight extractives and aroma-active compounds. The taste-active compoimds are more abundant in the tissues of mollusks and crustaceans than fish. The most important non-volatile taste components are fi-ee amino acids, nucleotides, inorganic salts and quaternary ammonia bases. Alcohols, aldehydes, ketones, furans, nitrogen-containing compounds, sulfur-containing compounds, hydrocarbons, esters and phenols are the most important volatiles is shellfish. Alkyl pyrazines and sulfur-containing compounds are important contributors to the cooked aroma of crustaceans. Furans pyrazines, and Lactones have been found in heat-treated seafoods. Dimethyl disulfide, dimethyl trisulfide, heterocyclic sulfiir-containing compounds (alkylthiophenes) have been found in most thermally treated crustaceans like prawn, crab, oyster, crayfish and shrimp (52). 

The amine (0.1 mole) is diazotized in hydrochloric or sulfuric acid solution by sodium nitrite (7 g), the volume of solution being kept as small as possible. The diazonium salt solution is neutralized with calcium carbonate and filtered, and trisodium hexanitritocobaltate (15 g) is stirred into the filtrate, whereupon the trisdiazonium salt usually separates as a solid. For conversion into the nitro compound this salt (10 g), finely powdered, is added in portions, at room temparature, with good stirring, to a solution of sodium nitrite (lOg) and copper sulfate (10 g) in water (60 ml) in which copper(i) oxide (4 g) is suspended. When evolution of nitrogen ceases the nitro compound is isolated either by extraction with a solvent, e.g., chloroform, or by basification of the solution and steam-distillation.172... 

By ammoniating mixtures of sulfuric and nitric acid or by combining their ammonium salts in special ways, it is possible to produce compounds containing both ammo-niacal and nitrate nitrogen in the form of true double salts. Three double salts have been identified ... 

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