WCO Explanatory Notes reproduced for reference. © World Customs Organization. Verify against official WCO publication.
29.25 - Carboxyimide-function compounds (including saccharin and its salts) and iminefunction compounds. 2925.11 2925.12 2925.19 2925.2 1 2925.29 - Imides and their derivatives; salts thereof : - - Saccharin and its salts - - Glutethimide (INN) - - Other - Imines and their derivatives; salts thereof: - - Chlordimeform (ISO) - - Other (A) IMIDES Imides have the general formula (R=NH), where R is a dibasic acyl radical. (1) Saccharin or 1,2-benzisothiazolin-3-one 1,l-dioxide and its salts. Saccharin is an odourless, white crystalline powder having a very sweet taste; its sodium and ammonium salts have a lower sweetening power but are more soluble. Tablets consisting solely of one of these products remain in this heading. Pre arations, used in human diets, consisting of a mixture of saccharin or its salts and a foodstuff, as lactose, are however excluded fiom this heading and fall in heading 21.06 (see Note L @) to Chapter 38 Those pr arations consisting of saccharin or its salts and substances, other than a foodstuff, suc as sodium ydrogencarbonate (sodium bicarbonate) and tartaric acid fall in heading 38.24. sue! h. TI (2) Succinimide, used in chemical synthesis. (3) Phthalimide, used in chemical synthesis. (4) Glutethimide. A psychotropic substance - see the list at the end of Chapter 29. Organic imide derivatives of inorganic acids are classified in heading 29.29. (B) IMINES Imines, like imides, are characterised by the group =NH, but it is linked to a non-acidic organic radical : (R,C=NH). (1) Guanidines. The action of cyanamide on ammonia gives an imino-urea known as yanidine; this can be regarded as derived from urea by replacing the oxygen of the , ( C=O) group by an imino group (=NHJ: J 3 2 N C O ~......................................................................................... (H2N) 2 c = m urea guanidine Guanidine is also formed in the oxidation of proteins; it can also be obtained synthetically. It is crystalline, colourless and deliquescent. Its derivatives include : (a) Diphenylguanidine. Rubber accelerator. (b) Di-o-tolylguanidine.Rubber accelerator. (c) o-Tolyldiguanide.Rubber accelerator. (2) Aldimines. These have the general formula (RCH=NR1) where R and R' are alkyI or aryl radicals (methyl, ethyl, phenyl, etc.) or sometimes hydrogen. They constitute the products known as Schfff's bases, the most important of which are : (a) Ethylideneaniline. (b) Butylideneaniline. (c) Aldol-a- and -,B-naphthylamines. (d) Ethylidene-p-toluidine. All these products are used in the rubber industry. (3) Imino ethers. (4) Amidines. (5) 2,6-Dichlorophenolindophenol. This heading excludes, however, cyclic polymers of aldimines (heading 29.33). -
1.- Except where the context otherwise requires, the headings of this Chapter apply only to : (a) Separate chemically defined organic compounds, whether or not containing impurities; (b) Mixtures of two or more isomers of the same organic compound (whether or not containing impurities), except mixtures of acyclic hydrocarbon isomers (other than stereoisomers), whether or not saturated (Chapter 27); (c) The products of headings 29.36 to 29.39 or the sugar ethers, sugar acetals and sugar esters, and their salts, of heading 29.40, or the products of heading 29.41, whether or not chemically defined; (d) The products mentioned in (a), (b) or (c) above dissolved in water; (e) The products mentioned in (a), (b) or (c) above dissolved in other solvents provided that the solution constitutes a normal and necessary method of putting up these products adopted solely for reasons of safety or for transport and that the solvent does not render the product particularly suitable for specific use rather than for general use; (f) The products mentioned in (a), (b), (c), (d) or (e) above with an added stabiliser (including an anti- caking agent) necessary for their preservation or transport; (g) The products mentioned in (a), (b), (c), (d), (e) or (f) above with an added anti-dusting agent or a colouring or odoriferous substance or an emetic added to facilitate their identification or for safety reasons, provided that the additions do not render the product particularly suitable for specific use rather than for general use; (h) The following products, diluted to standard strengths, for the production of azo dyes : diazonium salts, couplers used for these salts and diazotisable amines and their salts. 2.- This Chapter does not cover : (a) Goods of heading 15.04 or crude glycerol of heading 15.20; (b) Ethyl alcohol (heading 22.07 or 22.08); (c) Methane or propane (heading 27.11); (d) The compounds of carbon mentioned in Note 2 to Chapter 28; (e) Immunological products of heading 30.02; (f) Urea (heading 31.02 or 31.05); (g) Colouring matter of vegetable or animal origin (heading 32.03), synthetic organic colouring matter, synthetic organic products of a kind used as fluorescent brightening agents or as luminophores (heading 32.04) or dyes or other colouring matter put up in forms or packings for retail sale (heading 32.12); (h) Enzymes (heading 35.07); (ij) Metaldehyde, hexamethylenetetramine or similar substances, put up in forms (for example, tablets, sticks or similar forms) for use as fuels, or liquid or liquefied-gas fuels in containers of a kind used for filling or refilling cigarette or similar lighters and of a capacity not exceeding 300 cm3 (heading 36.06); (k) Products put up as charges for fire-extinguishers or put up in fire-extinguishing grenades, of heading 38.13; ink removers put up in packings for retail sale, of heading 38.24; or (l) Optical elements, for example, of ethylenediamine tartrate (heading 90.01). 3.- Goods which could be included in two or more of the headings of this Chapter are to be classified in that one of those headings which occurs last in numerical order. 4.- In headings 29.04 to 29.06, 29.08 to 29.11 and 29.13 to 29.20, any reference to halogenated, sulphonated, nitrated or nitrosated derivatives includes a reference to compound derivatives, such as sulphohalogenated, nitrohalogenated, nitrosulphonated or nitrosulphohalogenated derivatives. Nitro or nitroso groups are not to be taken as “nitrogen-functions” for the purposes of heading 29.29. For the purposes of headings 29.11, 29.12, 29.14, 29.18 and 29.22, “oxygen function”, the characteristic organic oxygen-containing group of those respective headings, is restricted to the oxygen-functions referred to in headings 29.05 to 29.20.