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This heading includes nucleic acids and their salts. These are complex compounds which, when combined with proteins, form the nucleo-proteins found in the nucleii of animal and vegetable cells. They are combinations of phosphoric acids with sugar and pyrimidine or purine compounds. Generally in the form of white powders, soluble in water.
The acids, or more often their salts (e.g., sodium and copper nucleates), are used as tonics and stimulants for the nervous system and solvents for uric acid.
The heterocyclic compounds covered by this heading are :(A) Compounds containing an unfused thiazole ring (whether or not hydrogenated) in the structure.
The term "thiazole" includes both 1,3-thiazole and 1,2-thiazole (isothiazole). (B) Compounds containing a benzothiazole ring-system (whether or not hydrogenated), not further fused.
The term "benzothiazole" includes both 1,3-benzothiazole and 1,2-benzothiazole (benzisothiazole).
This part includes, inter alia : (1) Mercaptobenzothiazole. White-yellowish fine powder. Used as an accelerator in the rubber industry. (2) Dibenzothiazolyl disulphide. Used as an accelerator in the rubber industry. (3) Ipsapirone (INN) (2-[4-(4-pyrimidin-2-ylpiperazin-1- yl)butyl]-1,2-benzothiazol-3(2H)-one 1,1-dioxide). Used as an anxiolytic. (C) Compounds containing a phenothiazine ring-system (whether or not hydrogenated), not further fused.
This part includes, inter alia :
Phenothiazine (thiodiphenylamine). Sparkling yellowish flakes or grey-green powder; used for the preparation of dyes, etc. (D) Other heterocyclic compounds.
This part includes, inter alia : (1) Sultones. These may be considered as internal esters of hydroxysulphonic acids. They include the sulphonephthaleins, for example : (a) Phenol red (phenolsulphonephthalein). Used in medicine and as an indicator in analysis. (b) Thymol blue (thymolsulphonephthalein). Used as a reagent. (c) 1,3-Propanesultone. (2) Sultams. These may be considered as internal amides of aminosulphonic acids. They include naphthosultam-2,4-disulphonic acid, obtained from periacid, and which is used for the manufacture of SS acid (8-amino-1-naphthol-5,7-disulphonic acid or 1-amino-8-naphthol-2,4-disulphonic acid). (3) Thiophen. Found in coal and lignite tars. Also obtained synthetically. A mobile, colourless liquid with a benzene-like odour. (4) Furazolidone (INN) (3-(5-nitrofurfurylideneamino) oxazolidin-2-one). (5) Dehydrothio-p-toluidine. (6) Adenosine tri- or pyrophosphoric acid. (7) 3-Methyl-6,7-methylenedioxy-1-(3,4-methylenedioxybenzyl)isoquinoline hydrochloride. (8) 3-Methyl-6,7-methylenedioxy-1-(3,4-methylenedioxyphenyl)isoquinoline.
This heading excludes mercury nucleates answering to a description in heading 28.52, and cyclic polymers of thioaldehydes (heading 29.30). Certain substances of this heading, which are regarded as narcotic drugs or as psychotropic substances under international instruments, are indicated in the list appearing at the end of Chapter 29.
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