Shipping to 128 countriesCOA and SDS with every lotQuotes within one business day
contact@zemixal.com
Bulk CASAccount
Pharmaceutical Intermediates

Heterocyclic Building Blocks

Nitrogen, oxygen and sulphur heterocycles, including pyridines, pyrimidines, indoles, piperazines and triazoles, for medicinal and process chemistry.
2,832 products11 sub-categories83 in stockCOA + SDS with every lot
2,832 products · page 1 of 118
GridList

Most small-molecule drugs contain at least one heterocycle, which makes this sub-category a daily resource for medicinal chemists. It is divided by ring system: pyridines, pyrimidines and pyrazines, indoles, quinolines, imidazoles and benzimidazoles, triazoles and tetrazoles, thiophenes and thiazoles, furans and coumarins, saturated rings such as piperidines, piperazines and morpholines, and pyrroles and pyrazoles. Examples include 2,4,6-Trichloropyrimidine, 1-(4-Pyridyl)piperazine, 2-Methyl indole and 1,2,4-Triazole.

Heterocycle selection usually turns on substitution pattern and the handle for the next step, such as a halogen for cross-coupling or a protected amine. Regioisomer purity is worth checking, because closely related isomers are hard to separate after coupling. Each listing gives the substitution pattern clearly with CAS and structure.

Items ship from small research packs to kilogram quantities, each with a COA and SDS. Custom heterocycles can be made to order when a substitution pattern is not in stock.

Heterocyclic Building Blocks: questions buyers ask

Why does regioisomer purity matter for heterocycles?
Many heterocycles are made by reactions that give mixtures of positional isomers. These isomers have similar properties and often carry through coupling steps, ending up as hard-to-remove impurities in the final compound. Checking isomer content on the COA early avoids difficult purification and misleading biological results.
Which halogenated heterocycles work best for cross-coupling?
Bromides and iodides couple readily under Suzuki and Buchwald conditions, while chlorides are cheaper but need more active catalysts. In polyhalogenated heterocycles such as trichloropyrimidine, positions react at different rates, allowing selective sequential substitution. Choose the halogen pattern that fits your planned order of reactions.
Can you supply heterocyclic intermediates at kilogram scale?
Many listed heterocycles are produced in India at kilogram scale and above. For larger orders we confirm the route, impurity profile and lead time, and can share a recent COA and sample in advance. Send quantities and specifications through the quote panel for a scale-up offer.

Have a list of compounds to price?

Paste up to 200 CAS numbers into Bulk CAS lookup, or send one enquiry for everything in your quote list. We reply with price, lead time and documents.

Bulk CAS lookup Open quote list
Compare 0 of 4Compare now