Chapter 2933 — Customs Tariff Headings

Aminophenazone

Aminophenazone is a derivative of phenazone (antipyrin) with an amino group substitution, retaining the unfused pyrazole ring structure. It is used primarily as an intermediate in pharmaceutical synthesis. This compound falls under tariff item 2933.11.00 as a phenazone derivative.

Isopropphenazone

Isopropphenazone is an isopropyl-substituted derivative of phenazone, maintaining the unfused pyrazole ring. It serves as a pharmaceutical intermediate in the synthesis of active ingredients. This product is classified under tariff item 2933.11.00 as a phenazone derivative.

Metamizole Sodium (Analgin)

Metamizole sodium, also known as Analgin, is a water-soluble sodium salt of a phenazone derivative. As an inorganic salt of an organic compound, it is classified with the parent phenazone compound under Chapter Note 5(C)(1). It is used as a potent analgesic and antipyretic.

N-Methylphenazone

N-Methylphenazone is an N-alkylated derivative of phenazone, retaining the unfused pyrazole ring. It is used in organic synthesis and as a pharmaceutical intermediate. This compound is classified under tariff item 2933.11.00 as a phenazone derivative.

Phenazone (Antipyrine)

Phenazone, also known as antipyrine, is a pyrazolone derivative with an unfused pyrazole ring. It has historical use as an analgesic and antipyretic. This product is explicitly named in tariff item 2933.11.00.

Phenazone Salicylate

Phenazone salicylate is a salt formed between phenazone and salicylic acid, used in topical analgesic preparations such as ear drops. Under Chapter Note 5(C)(2), salts formed between organic compounds are classified with the compound occurring last in numerical order, which is phenazone. It falls under tariff item 2933.11.00.

Phenzone (Phenylethylphenazone)

Phenzone, also known as phenylethylphenazone, is a phenazone derivative with a phenylethyl group, retaining the unfused pyrazole ring. It is used in anti-inflammatory formulations. This compound is classified under tariff item 2933.11.00 as a phenazone derivative.

Propyphenazone

Propyphenazone is an N-propyl derivative of phenazone, maintaining the unfused pyrazole ring. It is used in combination analgesics. This product is classified under tariff item 2933.11.00 as a phenazone derivative.

1-(2',5'-Dichlorophenyl)-3-methyl-2-pyrazolin-5-one

> 1-(2',5'-Dichlorophenyl)-3-methyl-2-pyrazolin-5-one is a chemically defined compound with an unfused pyrazole ring and dichlorophenyl substitution. It is used in specialty azo dyes and pharmaceutical synthesis. This product is classified under tariff item 2933.19.00 as an "Other" compound.

1-(m-Chlorophenyl)-3-methyl-2-pyrazolin-5-one

> 1-(m-Chlorophenyl)-3-methyl-2-pyrazolin-5-one is a chemically defined compound with an unfused pyrazole ring and chlorophenyl substitution. It is used as a dye intermediate and in pharmaceutical synthesis. This product is classified under tariff item 2933.19.00 as an "Other" compound.

1-(o-Ethylphenyl)-3-methyl-2-pyrazolin-5-one

> 1-(o-Ethylphenyl)-3-methyl-2-pyrazolin-5-one is a chemically defined compound with an unfused pyrazole ring and ethylphenyl substitution. It is employed in dye chemistry and polymer additives. This product is classified under tariff item 2933.19.00 as an "Other" compound.

2,4-Methylcarboxypyrazolic acid

> 2,4-Methylcarboxypyrazolic acid is a chemically defined compound with an unfused pyrazole ring and carboxy substitution. It is used in fine chemical synthesis. This product is classified under tariff item 2933.19.00 as an "Other" compound.

3-(5-Amino-3-methyl-1H-pyrazol-1-yl)-benzenesulfonic acid

> 3-(5-Amino-3-methyl-1H-pyrazol-1-yl)-benzenesulfonic acid is a chemically defined compound with an unfused pyrazole ring and sulfonic acid group. It serves as an intermediate in the synthesis of azo dyes and pharmaceuticals. This product is classified under tariff item 2933.19.00 as an "Other" compound.

3-Amino-1-(2,4,6-trichlorophenyl)-5-pyrazolone

> 3-Amino-1-(2,4,6-trichlorophenyl)-5-pyrazolone is a chemically defined compound with an unfused pyrazole ring and trichlorophenyl substitution. It is used in synthesis of dyes and pharmaceuticals. This product is classified under tariff item 2933.19.00 as an "Other" compound.

3-Carboxy-1,4-sulfophenylpyrazol-5-one

> 3-Carboxy-1,4-sulfophenylpyrazol-5-one is a chemically defined compound with an unfused pyrazole ring and sulfonic/carboxy substitution. It is an essential intermediate for acid dyes and pharmaceuticals. This product is classified under tariff item 2933.19.00 as an "Other" compound.

3-Methyl-1-(p-tolyl)-2-pyrazolin-5-one (p-Tolyl Methyl Pyrazolone)

> 3-Methyl-1-(p-tolyl)-2-pyrazolin-5-one is a chemically defined organic compound containing an unfused pyrazole ring with nitrogen hetero-atoms. It is commonly used as a dye intermediate and in pharmaceutical synthesis. This product falls under tariff item 2933.19.00 as an "Other" compound with an unfused pyrazole ring, not elsewhere specified.

Aminomethylphenylpyrazole (Phenylmethylaminopyrazole)

> Aminomethylphenylpyrazole is a chemically defined aromatic heterocyclic compound containing an unfused pyrazole ring with nitrogen hetero-atoms. It serves as a key intermediate in pharmaceutical and agrochemical synthesis. This product is classified under tariff item 2933.19.00 as an "Other" compound with an unfused pyrazole ring.

Aminomethylphenylpyrazole with Stabilizer

> Aminomethylphenylpyrazole with stabilizer is a chemically defined compound with an added anti-caking agent for preservation and transport, as permitted by Chapter 29 Note 1(f). It remains classified under tariff item 2933.19.00 as an "Other" compound with an unfused pyrazole ring. This stabilized form is used in bulk for pharmaceutical research and development.

High-Purity Aminomethylphenylpyrazole for Pharma

> High-Purity Aminomethylphenylpyrazole for Pharma is a 99.5% pure chemically defined compound with an unfused pyrazole ring. It is used as an intermediate for antiviral drug synthesis. This product is classified under tariff item 2933.19.00 as an "Other" compound with an unfused pyrazole ring, meeting Chapter 29 requirements for separate chemically defined organic compounds.

Phenylmethylaminopyrazole Technical Grade Powder

> Phenylmethylaminopyrazole Technical Grade Powder is a pure aromatic pyrazole compound with impurities that do not affect its chemical definition. It is used in fine chemical synthesis for herbicides and drugs. This product falls under tariff item 2933.19.00 as an "Other" compound with an unfused pyrazole ring, per Chapter 29 Note 1(a).

p-Tolyl Methyl Pyrazolone Aqueous Solution

> p-Tolyl Methyl Pyrazolone Aqueous Solution is a solution of the chemically defined compound in water, as permitted by Chapter 29 Note 1(d). It is used for safe lab handling in dye production. This product is classified under tariff item 2933.19.00 as an "Other" compound with an unfused pyrazole ring.

p-Tolyl Methyl Pyrazolone Crystals 99% Purity

> p-Tolyl Methyl Pyrazolone Crystals 99% Purity is a high-purity crystalline form of 3-Methyl-1-(p-tolyl)-2-pyrazolin-5-one, a chemically defined compound with an unfused pyrazole ring. It is essential for azo dye coupling and analgesic synthesis. This product is classified under tariff item 2933.19.00 as an "Other" compound.

p-Tolyl Methyl Pyrazolone Dye Coupler

> p-Tolyl Methyl Pyrazolone Dye Coupler is a specialty grade of the chemically defined compound optimized for use as a dye coupler. It remains a pure compound, not formulated, and is used in azo pigment production. This product is classified under tariff item 2933.19.00 as an "Other" compound with an unfused pyrazole ring.

5,5-Diphenylhydantoin (Phenytoin Base)

5,5-Diphenylhydantoin (Phenytoin Base) is the active pharmaceutical base form of the anticonvulsant phenytoin, a classic hydantoin derivative. It is a separate chemically defined organic compound with an unfused imidazole ring, classifiable under tariff item 2933.21.00.

Allantoin USP

Allantoin USP is a chemically defined hydantoin derivative with an unfused imidazole ring, used in cosmetics, pharmaceuticals, and wound-healing products for its soothing and keratolytic properties. It is classified under tariff item 2933.21.00 as a hydantoin derivative, meeting the chapter 29 criteria for separate chemically defined organic compounds.

Dimethylol Propylene Urea

Dimethylol Propylene Urea is a hydantoin derivative used as a formaldehyde-free crosslinking agent in textile finishing and paper treatment. It is a separate chemically defined organic compound with an unfused imidazole ring, classifiable under tariff item 2933.21.00.

Methone (5,5-Dimethylhydantoin)

Methone (5,5-Dimethylhydantoin) is a hydantoin derivative used as an intermediate in pharmaceutical synthesis and polymer modification. It is a separate chemically defined organic compound with an unfused imidazole ring, classifiable under tariff item 2933.21.00.

Methylethylketone Peroxide Stabilized with Hydroxypropyl Methacrylate

Methylethylketone Peroxide Stabilized with Hydroxypropyl Methacrylate is a hydantoin-structured curing agent used in polymer composites and gelcoat resins. Despite the stabilizer, the core hydantoin compound is classifiable under tariff item 2933.21.00 as a hydantoin derivative, provided the stabilizer does not alter its essential character.

Nitroso-Dimethylol Urea

Nitroso-Dimethylol Urea is a hydantoin derivative used as a slow-release nitrogen source in agricultural applications and slow-cure resins. It is a separate chemically defined organic compound with an unfused imidazole ring, classifiable under tariff item 2933.21.00.

Parabanic Acid

Parabanic Acid is a simple hydantoin derivative used as an analytical reagent and synthetic intermediate. It is a separate chemically defined organic compound with an unfused imidazole ring, classifiable under tariff item 2933.21.00.

2-Imidazolidinethione (Ethylene Thiourea) Crystals

Crystalline ethylene thiourea (2-imidazolidinethione) is a heterocyclic organic compound containing an unfused imidazolidine ring with a sulfur atom. It is a key reagent in the synthesis of ethylenebisdithiocarbamate fungicides and rubber additives, qualifying under tariff item 2933.29.00 as an 'other' heterocyclic compound with nitrogen hetero-atom(s) only.

2-Phenyl-4-Methylimidazole

2-Phenyl-4-methylimidazole is a modified aromatic imidazole derivative with a phenyl group at the 2-position and a methyl group at the 4-position. It is used in photographic chemicals and contains an unfused imidazole ring, classifiable under tariff item 2933.29.00 as an 'other' heterocyclic compound.

2-Phenylimidazole

2-Phenylimidazole is a heterocyclic compound containing an unfused imidazole ring with a phenyl group at the 2-position. It is used as an epoxy resin curing agent and in chemical synthesis, classifiable under tariff item 2933.29.00 as an 'other' heterocyclic compound with nitrogen hetero-atom(s) only.

2-Phenylimidazole Hydrochloride Salt

2-Phenylimidazole hydrochloride salt is a water-soluble form of 2-phenylimidazole, used in pharmaceutical applications. Per Chapter 29 Note 5, inorganic salts of organic compounds are classified with the parent organic compound, so this salt falls under tariff item 2933.29.00.

2-Phenylimidazole Technical Grade

Technical grade 2-phenylimidazole (95-98% purity) is used in epoxy resin curing agents and corrosion inhibitors. It is a chemically defined aromatic heterocyclic compound with an unfused imidazole ring, classifiable under tariff item 2933.29.00 as an 'other' heterocyclic compound.

Clotrimazole API

Clotrimazole API is an aromatic imidazole antifungal agent with an unfused imidazole ring structure. It is used in pharmaceutical formulations for topical and oral candidiasis treatment, classifiable under tariff item 2933.29.00 as an 'other' heterocyclic compound.

Econazole Nitrate BP

Econazole nitrate BP is an imidazole derivative with an aromatic structure, used as a broad-spectrum antifungal for dermatological applications. It is a chemically defined organic compound with an unfused imidazole ring, classifiable under tariff item 2933.29.00.

Ethylene Thiourea (2-Imidazolidinethione)

Ethylene thiourea, chemically 2-imidazolidinethione, is a heterocyclic imidazolidine compound used as a chemical intermediate and accelerator in rubber vulcanization. It is a separate chemically defined organic compound with an unfused ring containing nitrogen and sulfur, falling under tariff item 2933.29.00 as an 'other' heterocyclic compound.

Ethylene Thiourea Industrial Grade

Industrial grade ethylene thiourea, featuring the 2-imidazolidinethione structure, is used as an essential intermediate for dithiocarbamate pesticides and rubber processing. It is a chemically defined organic compound with an unfused imidazolidine ring, classifiable under tariff item 2933.29.00 as an 'other' heterocyclic compound.

High Purity 2-Phenylimidazole (99%+)

High purity 2-phenylimidazole (99%+) is a pharmaceutical-grade compound used in antifungal drug synthesis and as a ligand in coordination chemistry. It is a separate chemically defined organic compound with an unfused imidazole ring, classifiable under tariff item 2933.29.00.

Industrial 2-Phenylimidazole for Resin Curing

Industrial 2-phenylimidazole is bulk-packaged for epoxy resin curing applications in electronics. It is a pure aromatic heterocyclic compound, not a finished resin, and falls under tariff item 2933.29.00 as an 'other' heterocyclic compound with nitrogen hetero-atom(s) only.

Ketoconazole Base

Ketoconazole base is an aromatic imidazole derivative with an unfused imidazole ring, used systemically for fungal infections and hormonal disorders. It is a separate chemically defined organic compound, classifiable under tariff item 2933.29.00 as an 'other' heterocyclic compound.

Triflumizole 98% Technical Powder

Triflumizole technical powder (98% minimum purity) is a heterocyclic compound containing an unfused imidazole ring with a 4-chloro-2-(trifluoromethyl)phenyl group. It is used as a fungicide active ingredient for crop protection, classifiable under tariff item 2933.29.00 as an 'other' heterocyclic compound with nitrogen hetero-atom(s) only.

Triflumizole Fungicide Active Ingredient

Triflumizole active ingredient is a pure imidazole fungicide with a characteristic 4-chloro-2-(trifluoromethyl)phenyl structure. It is a chemically defined organic compound with an unfused imidazole ring, used in crop protection formulations, and falls under tariff item 2933.29.00 as an 'other' heterocyclic compound.

Triflumizole Technical Grade

Triflumizole technical grade is a specific imidazole fungicide with the chemical name 1-[1-((4-chloro-2-(trifluoromethyl)phenyl)-imino)-2-propoxyethyl]-1H-imidazole. It features an unfused aromatic imidazole ring and is used in agricultural applications, classifiable under tariff item 2933.29.00.

2-Aminopyridine (CAS 109-06-8)

2-Aminopyridine is an aromatic amine derivative featuring an unfused pyridine ring with an amino group at the 2-position. It is primarily used as an intermediate in pharmaceutical and agrochemical synthesis. Despite the amino substitution, the compound retains the pyridine ring structure, which governs its classification under this tariff item.

2-Picoline (2-Methylpyridine) (CAS 109-06-8)

2-Picoline, also known as 2-methylpyridine, is a liquid alkyl derivative of pyridine with a methyl group at the 2-position. It is widely used in the production of agrochemicals, pharmaceuticals, and rubber chemicals. The single methyl substitution does not alter the fundamental pyridine ring structure, keeping it within the scope of this tariff item.

4-Dimethylaminopyridine (DMAP) (CAS 1122-58-3)

4-Dimethylaminopyridine (DMAP) is a pyridine derivative with a dimethylamino group at the 4-position, widely used as a nucleophilic catalyst in esterification and acylation reactions. Its classification is determined by the unfused pyridine ring, which is the core structural feature. DMAP is a separate chemically defined organic compound, meeting Chapter 29 requirements.

Pyridine-3-carboxylic Acid (Nicotinic Acid) (CAS 59-67-6)

Nicotinic acid, also known as pyridine-3-carboxylic acid or vitamin B3, is a pyridine derivative with a carboxylic acid group at the 3-position. It is essential for human nutrition and used in pharmaceutical and food applications. The pyridine ring structure is the primary determinant for classification under this tariff item, despite the carboxylic acid function.

Pyridine (CAS 110-86-1)

Pyridine is the base compound of this tariff item, a flammable, colorless liquid with the formula C5H5N, containing an unfused pyridine ring. It is used as a solvent and reagent in organic synthesis for pharmaceuticals, agrochemicals, and other industrial applications. As the parent compound, it is directly covered by this tariff item.

Pyridine Hydrochloride (CAS 628-13-7)

Pyridine hydrochloride is the crystalline salt formed from pyridine and hydrochloric acid, used as a catalyst and reagent in organic reactions. It contains the pyridine ring structure and is classified with the organic base per Chapter 29 Note 5(C)(1). The salt form is a separate chemically defined compound, meeting the requirements of this tariff item.

Pyridine N-Oxide (CAS 694-59-7)

Pyridine N-oxide is a derivative of pyridine where an oxygen atom is bonded to the nitrogen, forming an N-oxide. It is used as an intermediate in organic synthesis, particularly in oxidation reactions. The compound retains the pyridine ring structure, and the N-oxide function does not exclude it from this tariff item, as it remains a separate chemically defined organic compound.

Pyridine Sulfate

Pyridine sulfate is the acidic salt formed from pyridine and sulfuric acid, used in analytical chemistry and as a reagent. Per Chapter 29 Note 5(C)(1), inorganic salts of organic compounds are classified with the organic compound, which is pyridine. The salt is a separate chemically defined compound, meeting the requirements of this tariff item.