Heading 2933
Heterocyclic compounds with nitrogen hetero-atom(s) only
128 declarable lines
Heading 2933 covers heterocyclic compounds that contain only nitrogen as the hetero-atom, meaning the ring system has nitrogen but no oxygen, sulfur or other hetero-atom in the ring. The heading is split by ring type: unfused pyrazole, imidazole, pyridine, quinoline and isoquinoline, pyrimidine and piperazine, triazine, then lactams, then a residual Other group. Within each ring group the lines separate aromatic from non-aromatic forms and then break out pesticides, drugs, photographic chemicals and specific named compounds.
Products in this heading
- Melamine (2933.61.00.00)
- Diazepam (2933.91.00.50)
- 6-Hexanelactam, also called caprolactam (2933.71.00.00)
- N-Methyl-2-pyrrolidone (2933.79.20.00)
- Hexamethylenetetramine (2933.69.50.00)
- Cyanuric chloride (2933.69.60.10)
- Benzotriazole (2933.99.82.10)
- Piperidine (2933.32.10.00)
How to choose the right subheading
- Identify the ring system in the molecule: pyrazole, imidazole, pyridine, quinoline or isoquinoline, pyrimidine or piperazine, triazine, lactam, or none of these.
- Decide whether the compound is aromatic or modified aromatic, because each ring group splits on that basis before any use-based lines.
- Check whether the specific chemical name is listed in a basket line, such as the named pyrazolones in 2933.19.08.00.
- Determine the principal use when a use-based line applies: pesticide, drug, photographic chemical, or rubber processing.
- For lactams, confirm the ring is a lactam and note the separate lines for caprolactam, N-methyl-2-pyrrolidone and N-vinyl-2-pyrrolidone.
Often confused with
- Heading 2941Penicillin and other antibiotics
Antibiotics sit in their own heading even when the molecule contains a nitrogen heterocycle.
- Heading 2925Saccharin and its salts
Saccharin is a carboxyimide-function compound and is named in heading 2925.
- Heading 2939Caffeine and other alkaloids
Alkaloids of natural origin are classified in heading 2939, not with synthetic nitrogen heterocycles.
- Heading 2936Vitamin B6 and other vitamins
Vitamins and provitamins go to heading 2936 even though several have nitrogen heterocycles.
- Heading 2937Insulin and other polypeptide hormones
Hormones are classified in heading 2937 rather than by ring structure.
Frequently asked questions
What is the HTS code for melamine?
Melamine is classified under 2933.61.00.00, the line for melamine in the unfused triazine group. The general (MFN) rate for that line is 3.5%.
What is the duty on diazepam imported into the United States?
Diazepam falls under 2933.91.00.50, the residual line for the named benzodiazepines and their salts. The general (MFN) rate on that line is Free.
How do I classify caprolactam?
Caprolactam, described as 6-hexanelactam, is a lactam and is named in 2933.71.00.00. The general (MFN) rate for that line is 6.5%.
Guide written from the official schedule text. Rates quoted are general (MFN) rates; check the line page for trade agreement rates and the classification of your exact product.
All lines in heading 2933
- 2933.11.00.00Phenazone (Antipyrine) and its derivatives6.5%
- 2933.19.04.00Aminomethylphenylpyrazole (Phenylmethylaminopyrazole); and 3-Methyl-1-(p-tolyl)-2-pyrazolin-5-one (p-Tolyl methyl pyrazolone)Free
- 2933.19.08.003-(5-Amino-3-methyl-1H-pyrazol-1-yl)- benzenesulfonic acid; Amino-J-pyrazolone; 3-Amino-1-(2,4,6-trichlorophenyl)-5- pyrazolone; 3-Carboxy-1,4-sulfophenylpyrazol-5-one; 4-Chloro-3-(3-methyl-5-oxo-2-pyrazolin-1- yl)benzenesulfonic acid; 1-(m-Chlorophenyl)-3-methyl-2-pyrazolin- 5-one;p-Chloropyrazolone; 1-(2',5'-Dichlorophenyl)-3-methyl-2- pyrazolin-5-one; 1-(o-Ethylphenyl)-3-methyl-2-pyrazolin- 5-one; 5-Imino-3-methyl-1-phenylpyrazole; 5-Imino-3-methyl-1-(m-sulfophenyl)- pyrazole; 2,4-Methylcarboxypyrazolic acid; Methylphenylpyrazolone; and Sulfinpyrazone5.8%
- 2933.19.15.001,2-Dimethyl-3,5-diphenyl-1H-pyrazolium methyl sulfate (Difenzoquat methyl sulfate)Free
- 2933.19.18.002-Chloro-5-sulfophenylmethylpyrazolone; 2,5-Dichloro-4-(3-methyl-5-oxo-2- pyrazolin-1-yl) benzenesulfonic acid; Phenyl carbethoxypyrazolone;m-Sulfaminopyrazolone (m-Sulfamido- phenyl methyl pyrazolone); and 1-(p-Sulfophenyl)-3-methyl pyrazoloneFree
- 2933.19.23.00Heterocyclic compounds with nitrogen hetero-atom(s) only / Aromatic or modified aromatic / Pesticides6.5%
- 2933.19.30.10Couplers, for use in color negative photographic paper6.5%
- 2933.19.30.95Aromatic or modified aromatic / Photographic chemicals / Other6.5%
- 2933.19.35.00Heterocyclic compounds with nitrogen hetero-atom(s) only / Aromatic or modified aromatic / Drugs6.5%
- 2933.19.37.00Products described in additional U.S. note 3 to section VI6.5%
- 2933.19.43.00Heterocyclic compounds with nitrogen hetero-atom(s) only / Aromatic or modified aromatic / Other6.5%
- 2933.19.45.00Heterocyclic compounds with nitrogen hetero-atom(s) only / Drugs3.7%
- 2933.19.70.00Heterocyclic compounds with nitrogen hetero-atom(s) only / 3-Methyl-5-pyrazoloneFree
- 2933.19.90.00Heterocyclic compounds with nitrogen hetero-atom(s) only / Other6.5%
- 2933.21.00.00Heterocyclic compounds with nitrogen hetero-atom(s) only / Hydantoin and its derivatives6.5%
- 2933.29.05.001-[1-((4-Chloro-2-(trifluoromethyl)phenyl)- imino)-2-propoxyethyl]-1H-imidazole (Triflumizole); and Ethylene thioureaFree
- 2933.29.10.00Heterocyclic compounds with nitrogen hetero-atom(s) only / Aromatic or modified aromatic / 2-Phenylimidazole5.8%
- 2933.29.20.00Heterocyclic compounds with nitrogen hetero-atom(s) only / Aromatic or modified aromatic / Drugs6%
- 2933.29.35.00Products described in additional U.S. note 3 to section VI6.5%
- 2933.29.43.00Heterocyclic compounds with nitrogen hetero-atom(s) only / Aromatic or modified aromatic / Other6.5%
- 2933.29.45.00Heterocyclic compounds with nitrogen hetero-atom(s) only / Drugs3.7%
- 2933.29.60.00Heterocyclic compounds with nitrogen hetero-atom(s) only / ImidazoleFree
- 2933.29.90.00Heterocyclic compounds with nitrogen hetero-atom(s) only / Other6.5%
- 2933.31.00.00Heterocyclic compounds with nitrogen hetero-atom(s) only / Pyridine and its saltsFree
- 2933.32.10.00Heterocyclic compounds with nitrogen hetero-atom(s) only / Piperidine and its salts / Piperidine6.5%
- 2933.32.50.00Heterocyclic compounds with nitrogen hetero-atom(s) only / Piperidine and its salts / Other6.5%
- 2933.33.01.00Alfentanil (INN), anileridine (INN), bezitramide (INN), bromazepam (INN), carfentanil (INN), difenoxin (INN), diphenoxylate (INN), dipipanone (INN), fentanyl (INN), ketobemidone (INN), methylphenidate (INN), pentazocine (INN), pethidine (INN), pethidine (INN) intermediate A, phencyclidine (INN) (PCP), phenoperidine (INN), pipradrol (INN), piritramide (INN), propiram (INN), remifentanil (INN) and trimeperidine (INN); salts thereofFree
- 2933.34.00.00Heterocyclic compounds with nitrogen hetero-atom(s) only / Other fentanyls and their derivatives6.5%
- 2933.35.00.00Heterocyclic compounds with nitrogen hetero-atom(s) only / 3-Quinuclidinol5.8%
- 2933.36.00.004-Anilino-N-phenethylpiperidine (ANPP)6.5%
- 2933.37.00.00N-Phenethyl-4-piperidone (NPP)6.5%
- 2933.39.08.001-(3-Sulfo propyl) pyridinium hydroxide;N,N'-Bis (2,2,6,6-tetra methyl-4-piperidinyl)-1,6- hexane diamine; 3,5-Dimethyl-2-hydroxy methyl-4-methoxy- pyridine (pyrmethyl alcohol); Dipenta methylene thiuram tetra sulfide; 2H-Indol-2-one,1,3-dihydro-1-phenyl-3-(4- pyridinyl methylene); 4-Picolyl chloride hydro chloride; and Piperidino ethyl chloride hydro chlorideFree
- 2933.39.10.00Collidines, lutidines and picolinesFree
- 2933.39.20.00p-Chloro-2-benzylpyridine; 4-Chloro-1-methylpiperidine hydrochloride; 1,4-Dimethyl-6-hydroxy-3-cyanopyrid-2-one; Di-(2,2,6,6-tetramethyl-4-hydroxy- piperidine)sebacate; 2-Methyl-5-ethylpyridine; 4-Phenylpropylpyridine; α-Phenylpyridylacetic acid, methyl ester; Picolinic acid; 2-Pyridinecarboxaldehyde; and 2,5-Pyridinedicarboxylic acid5.8%
- 2933.39.21.00Heterocyclic compounds with nitrogen hetero-atom(s) only / Pesticides / Fungicides6.5%
- 2933.39.23.00Heterocyclic compounds with nitrogen hetero-atom(s) only / Pesticides / Herbicides / o-Paraquat dichloride6.5%
- 2933.39.25.00Heterocyclic compounds with nitrogen hetero-atom(s) only / Pesticides / Herbicides / Other6.5%
- 2933.39.27.00Heterocyclic compounds with nitrogen hetero-atom(s) only / Pesticides / Other6.5%
- 2933.39.31.00Antidepressants, tranquilizers and other psychotherapeutic agents6.5%
- 2933.39.41.00Heterocyclic compounds with nitrogen hetero-atom(s) only / Drugs / Other6.5%
- 2933.39.61.10Products described in additional U.S. note 3 to section VI / 3-Quinuclidinyl benzilate6.5%
- 2933.39.61.201-[N,N-Dialkyl (≤C10)-N-(n-(hydroxyl, cyano, acetoxy)alkyl (≤C10)) ammonio]-n-n-[N-(3- dimethylcarbamoxy-α-picolinyl)-N,N-dialkyl (≤C10) ammonio]decane dibromide (n=1-8)6.5%
- 2933.39.61.301,n-Bis[N-(3-dimethylcarbamoxy-α-picolyl)- N,N-dialkyl (≤ C10) ammonio]-alkane-(2,(n-1)- dione) dibromide (n=2-12)6.5%
- 2933.39.61.40N-phenyl-4-piperidinamine (4-AP), tert-butyl 4-(phenylamino)piperidine-1-carboxylate (tert-butyl 4-anilinopiperidine-1-carboxylate, 1-boc-4-AP), norfentanyl (N-phenyl-N-(4-piperidyl)propionamide), piperidin-4-one (4-piperidone) and tert-butyl 4-oxopiperidine-1-carboxylate (1-boc-4-piperidone); salts thereof6.5%
- 2933.39.61.92Products described in additional U.S. note 3 to section VI / Other6.5%
- 2933.39.92.00Heterocyclic compounds with nitrogen hetero-atom(s) only / Other6.5%
- 2933.41.00.00Levorphanol (INN) and its saltsFree
- 2933.49.08.00Heterocyclic compounds with nitrogen hetero-atom(s) only / 4,7-Dichloroquinoline6.5%
- 2933.49.10.00Ethoxyquin (1,2-Dihydro-6-ethoxy-2,2,4- trimethylquinoline)6.5%
- 2933.49.15.008-Methylquinoline and Isoquinoline5.8%
- 2933.49.17.00Ethyl ethyl-6,7,8-trifluoro-1,4-dihydro-4-oxo-3- quinolinecarboxylateFree
- 2933.49.20.005-Chloro-7-iodo-8-quinolinol (Iodo chlo rhydroxy quin); Deco quinate; Diiodo hydroxy quin; and Oxy quinoline sulfate6.5%
- 2933.49.26.00Heterocyclic compounds with nitrogen hetero-atom(s) only / Drugs / Other6.5%
- 2933.49.30.00Heterocyclic compounds with nitrogen hetero-atom(s) only / Pesticides6.5%
- 2933.49.60.00Products described in additional U.S. note 3 to section VI6.5%
- 2933.49.70.00Heterocyclic compounds with nitrogen hetero-atom(s) only / Other6.5%
- 2933.52.10.00Malonylurea (Barbituric acid) and its salts / Malonylurea (barbituric acid)Free
- 2933.52.90.00Malonylurea (Barbituric acid) and its salts / OtherFree
- 2933.53.00.00Allobarbital (INN), amobarbital (INN), barbital (INN), butalbital (INN), butobarbital, cyclobarbital (INN), methylphenobarbital (INN), pentobarbital (INN), phenobarbital (INN), secbutabarbital (INN), secobarbital (INN) and vinylbital (INN); salts thereofFree
- 2933.54.00.00Heterocyclic compounds with nitrogen hetero-atom(s) only / Other derivatives of malonylurea (barbituric acid); salts thereof3.7%
- 2933.55.00.00Loprazolam (INN), mecloqualone (INN), methaqualone (INN) and zipeprol (INN); salts thereofFree
- 2933.59.10.00Pesticides / Aromatic or modified aromatic / Herbicides6.5%
- 2933.59.15.00Pesticides / Aromatic or modified aromatic / Other6.5%
- 2933.59.18.00Heterocyclic compounds with nitrogen hetero-atom(s) only / Pesticides / Other6.5%
- 2933.59.21.00Antihistamines, including those principally used as anti-nauseants6.5%
- 2933.59.22.00Aromatic or modified aromatic / Anti-infective agents / Nicarbazin; and Trimethoprim6.5%
- 2933.59.36.00Aromatic or modified aromatic / Anti-infective agents / Other6.5%
- 2933.59.46.00Antidepressants, tranquilizers and other psychotherapeutic agents6.5%
- 2933.59.53.00Drugs / Aromatic or modified aromatic / Other6.5%
- 2933.59.59.00Heterocyclic compounds with nitrogen hetero-atom(s) only / Drugs / Other3.7%
- 2933.59.70.00Products described in additional U.S. note 3 to section VI6.5%
- 2933.59.80.00Heterocyclic compounds with nitrogen hetero-atom(s) only / Aromatic or modified aromatic / Other6.5%
- 2933.59.85.002-Amino-4-chloro-6-methoxy pyrimidine; 2-Amino-4,6-di methoxy pyrimidine; and 6-Methyl uracilFree
- 2933.59.95.00Heterocyclic compounds with nitrogen hetero-atom(s) only / Other6.5%
- 2933.61.00.00Heterocyclic compounds with nitrogen hetero-atom(s) only / Melamine3.5%
- 2933.69.20.002,4-Diamino-6-phenyl-1,3,5-triazineFree
- 2933.69.50.00Heterocyclic compounds with nitrogen hetero-atom(s) only / Hexamethylenetetramine6.3%
- 2933.69.60.10Heterocyclic compounds with nitrogen hetero-atom(s) only / Cyanuric chloride3.5%
- 2933.69.60.15Sodium dichloroisocyanurate and trichloroisocyanuric acid3.5%
- 2933.69.60.21Heterocyclic compounds with nitrogen hetero-atom(s) only / Pesticides / Other3.5%
- 2933.69.60.30Products used principally for rubber processing3.5%
- 2933.69.60.50Heterocyclic compounds with nitrogen hetero-atom(s) only / Other3.5%
- 2933.71.00.006-Hexanelactam (ε-Caprolactam)6.5%
- 2933.72.00.00Clobazam (INN) and methyprylon (INN)Free
- 2933.79.04.002,5-Dihydro-3,6-diphenylpyrrolo-(3,4-c)- pyrrole-1,4-dioneFree
- 2933.79.08.00Products described in additional U.S. note 3 to section VI6.5%
- 2933.79.15.00Lactams / Aromatic or modified aromatic / Other6.5%
- 2933.79.20.00N-Methyl-2-pyrrolidone; and 2-Pyrrolidone4.2%
- 2933.79.30.00N-Vinyl-2-pyrrolidone, monomer5.5%
- 2933.79.40.0012-Aminododecanoic acid lactamFree
- 2933.79.85.00Heterocyclic compounds with nitrogen hetero-atom(s) only / Lactams / Other6.5%
- 2933.91.00.10Lorazepam (INN); salts thereofFree
- 2933.91.00.50Heterocyclic compounds with nitrogen hetero-atom(s) only / OtherFree
- 2933.92.00.00Heterocyclic compounds with nitrogen hetero-atom(s) only / Azinphos-methylFree
- 2933.99.01.00Butyl (R)-2-[4-(5-trifluoromethyl-2- pyridinyloxy)phenoxy]propanoateFree
- 2933.99.02.002-[4-[(6-Chloro-2-quinoxalinyl)oxy]phenoxy]- propionic acid, ethyl esterFree
- 2933.99.05.00Heterocyclic compounds with nitrogen hetero-atom(s) only / Aromatic or modified aromatic / Acridine and indoleFree
- 2933.99.06.00α-Butyl-α-(4-chlorophenyl)-1H-1,2,4- triazole-1- propanenitrile (Myclobutanil); andα-[2-(4-Chlorophenyl)ethyl]-α-phenyl-1H- 1,2,4-triazole-1-propanenitrile (Fenbuconazole)6.5%
- 2933.99.08.00Aceto acetyl-5-amino benz imidazolone; 3-(2H-Benzo triazol-2-yl)-5-(tert-butyl)-4- hydroxy benzene propanoic acid, C7-C9 branched or linear alkyl esters; 2-(2H-Benzotriazol-2-yl)-6-dodecyl-4- methyl phenol, in liquid form, branched and linear; and 1,3,3-Trimethyl-2-methyleneindolineFree
- 2933.99.11.00Heterocyclic compounds with nitrogen hetero-atom(s) only / Aromatic or modified aromatic / CarbazoleFree
- 2933.99.12.006-Bromo-5-methyl-1H-imidazo[4,5-b]- pyridine; 2-sec-Butyl-4-tert-butyl-6-(benzotriazol-2- yl)phenol; 2-tert-Butyl-4-methyl-6-(5-chlorobenzotri- azol-2-yl)phenol; 2,4-Di-tert-butyl-6-(benzotriazol-2-yl)phenol; 2,4-Di-tert-butyl-6-(5-chlorobenzotriazol-2- yl)phenol; 2,3-Dichloro-6-quinoxalinecarbonyl chloride; 1-Hydroxy-2-carbazolecarboxylic acid; 2-Hydroxy-3-carbazolecarboxylic acid; 2-Hydroxy-3-carbazolecarboxylic acid, sodium salt; Iminodibenzyl(10,11-dihydro-5H-dibenz- [b,f]azepine); Indoline; 3-Methylbenzo[f]quinoline; 2-Methylindoline; 2-Methylmercaptobenzimidazole; 1-Methyl-2-phenylindole; 1-Methylpyrazine; 2,4-Methylpyrazolic acid; 2-Phenylbenzimidazole; 2-Phenylindole; Tetramethylpyrazine; 2,3,5-Triphenyltetrazolium chloride;dl-Tryptophan; and Vinylcarbazole, monomer5.8%
- 2933.99.14.005-Amino-4-chloro-α-phenyl-3- pyridazinone6.5%
- 2933.99.16.00o-Diquat dibromide (1,1'-Ethylene- 2,2'-dipyridylium dibromide)Free
- 2933.99.17.01Aromatic or modified aromatic / Pesticides / Insecticides6.5%
- 2933.99.22.00Aromatic or modified aromatic / Pesticides / Other6.5%
- 2933.99.24.00Heterocyclic compounds with nitrogen hetero-atom(s) only / Aromatic or modified aromatic / Photographic chemicals6.5%
- 2933.99.26.00Aromatic or modified aromatic / Drugs / Antihistamines6.5%
- 2933.99.42.00Acriflavine; Acriflavine hydrochloride; Carbadox; and PyrazinamideFree
- 2933.99.46.00Aromatic or modified aromatic / Drugs / Anti-infective agents / Other6.5%
- 2933.99.51.00Aromatic or modified aromatic / Drugs / Cardiovascular drugs / Hydralazine hydrochlorideFree
- 2933.99.53.00Aromatic or modified aromatic / Drugs / Cardiovascular drugs / Other6.5%
- 2933.99.55.10Analgesics, antipyretics and nonhormonal anti-inflammatory agents / Tolmetin6.5%
- 2933.99.55.20Analgesics, antipyretics and nonhormonal anti-inflammatory agents / Tolmetin sodium dihydrate6.5%
- 2933.99.55.30Analgesics, antipyretics and nonhormonal anti-inflammatory agents / Tolmetin sodium (anhydrous)6.5%
- 2933.99.55.90Analgesics, antipyretics and nonhormonal anti-inflammatory agents / Other6.5%
- 2933.99.58.00Droperidol; and Imipramine hydrochlorideFree
- 2933.99.61.00Antidepressants, tranquilizers and other psychotherapeutic agents / Other6.5%
- 2933.99.65.00Anticonvulsants, hypnotics and sedatives6.5%
- 2933.99.70.00Drugs primarily affecting the central nervous system / Other6.5%
- 2933.99.75.00Aromatic or modified aromatic / Drugs / Other6.5%
- 2933.99.79.00Products described in additional U.S. note 3 to section VI6.5%
- 2933.99.82.10Benzotriazole (CAS No. 95-14-7)6.5%
- 2933.99.82.20Tolyltriazole (CAS No. 29385-43-1)6.5%
- 2933.99.82.90Heterocyclic compounds with nitrogen hetero-atom(s) only / Aromatic or modified aromatic / Other6.5%
- 2933.99.85.00Heterocyclic compounds with nitrogen hetero-atom(s) only / 3-Amino-1,2,4-triazole3.7%
- 2933.99.89.00Heterocyclic compounds with nitrogen hetero-atom(s) only / HexamethyleneimineFree
- 2933.99.90.00Heterocyclic compounds with nitrogen hetero-atom(s) only / Drugs3.7%
- 2933.99.97.01Heterocyclic compounds with nitrogen hetero-atom(s) only / Other6.5%