Product Overview

Bis(4-nitrophenyl) carbonate commonly abbreviated BNPC or PNP carbonate, and also catalogued as 4,4′-dinitrodiphenyl carbonate is an off-white to pale yellow crystalline powder used as a phosgene-free carbonylating and activating reagent.

Structurally it is carbonic acid esterified twice with 4-nitrophenol, and that arrangement is the whole point: the central carbonyl is strongly electrophilic and 4-nitrophenolate is an excellent leaving group.

React BNPC with an amine or an alcohol and one nitrophenyl group is displaced, giving an activated 4-nitrophenyl carbamate or carbonate.

Introduce a second nucleophile and the remaining nitrophenol departs, delivering a carbamate or an unsymmetrical urea.

It replaces phosgene, triphosgene and chloroformates across all of that chemistry, under mild conditions and without gas handling or chloride residues.

What separates BNPC from other phosgene substitutes is the stability of the intermediate.

The activated 4-nitrophenyl carbamate formed in the first step is a stable, isolable, storable solid.

It can be made, purified, characterised and held as a building block, then reacted with the second partner in a separate controlled operation.

That is very different from reagents whose activated species must be generated and consumed in situ, and it is the reason PNP carbonate activation became the standard approach in antibody-drug conjugate linker chemistry and in PEGylation, where the activated building block is often manufactured and shipped as its own article.

There is a second practical advantage.

The released 4-nitrophenol absorbs strongly in the visible region, so reaction progress and conjugation efficiency can be followed spectrophotometrically rather than by pulling samples for chromatography.

For bioconjugation work at small scale, that is a genuine workflow benefit.

We supply BNPC in a Technical / Non-GMP Grade for process development and non-regulated synthesis, and in a GMP Starting Material Grade produced under ICH Q7 principles for regulated routes. Every consignment carries a batch Certificate of Analysis and a GHS-format MSDS.

Actiza has over 12 years of B2B pharmaceutical export experience, 500+ global clients and a supply footprint across 40+ countries, backed by WHO-GMP and ISO-certified group manufacturing infrastructure in Gujarat, India.

Key Highlights

Technical / Non-GMP and GMP Starting Material grades available from one source.

Assay ≥ 98.0% by HPLC, verified on every batch.

Phosgene-free carbonylation no gas handling, no licensing burden, no chloride residues.

Forms stable, isolable activated carbamate intermediates suited to building-block workflows.

Mild GHS profile skin and eye irritation only, not toxic or corrosive.

Certificate of Analysis (COA) and MSDS supplied with every batch.

Cold-chain, light- and moisture-protected packing.

Application in Synthesis

BNPC has no therapeutic activity of its own.

It is consumed as an activating reagent, and its value lies in the controlled, two-stage way it delivers a carbonyl group between two different nucleophiles.

Reaction Chemistry at a Glance

Transformation	What Happens	Why It Matters
Amine + BNPC → activated carbamate	One nitrophenol displaced; activated 4-nitrophenyl carbamate formed	The intermediate is stable and isolabl, it can be purified and stored as a building block
Activated carbamate + amine → unsymmetrical urea	Second nitrophenol displaced	Clean route to unsymmetrical ureas without phosgene
Alcohol + BNPC → activated carbonate	One nitrophenol displaced	The activation step used in PEG and linker chemistry
Activated carbonate + amine → carbamate	Second nitrophenol displaced	Forms the carbamate linkage used in prodrugs and conjugates
Amino alcohol + BNPC → cyclic carbamate	Intramolecular closure	Oxazolidinone-type ring construction
N-protected amino acid + BNPC	Forms the 4-nitrophenyl active ester	Classical activated ester for peptide coupling

Downstream Pharmaceutical Applications

Application Area	Where BNPC Acts	Notes
Antibody-drug conjugate linkers	Activates the cleavable dipeptide-PAB linker to its PNP carbonate before payload attachment	Documented across published ADC process patents; the activated linker is often an isolated, characterised article in its own right
PEGylated conjugates and polymer-drug conjugates	Converts PEG hydroxyl termini to activated carbonates for amine conjugation	Enables carbamate-linked PEG conjugates with defined attachment chemistry
Carbamate prodrugs	Activates the parent drug hydroxyl or amine ahead of linker attachment	Used where a carbamate offers better stability than an ester linkage
Unsymmetrical urea APIs	Sequential displacement by two different amines	Phosgene-free access to the urea motif found in several kinase-inhibitor scaffolds
Peptide and peptidomimetic synthesis	Forms 4-nitrophenyl active esters of N-protected amino acids	Long-established activated-ester coupling chemistry
Carbamate-linked nucleoside derivatives	Carbonyl donor between nucleoside and partner	Reported in oligonucleotide and nucleoside conjugate chemistry
Polycarbonate and polyurethane chemistry	Carbonate and urethane linkage formation	Non-pharmaceutical segment

How BNPC Compares to CDI

Both are phosgene-free carbonylating reagents and buyers frequently evaluate them against each other, so the honest comparison is worth stating on the page:

Consideration	Bis(4-nitrophenyl) Carbonate	Carbonyldiimidazole (CDI)
Activated intermediate	Stable, isolable, storable	Usually generated and consumed in situ
Leaving group	4-Nitrophenol, lipophilic, UV-active, must be purged	Imidazole, water-soluble, easily washed out
Reaction monitoring	Nitrophenol release can be followed spectrophotometrically	Requires conventional in-process analysis
Work-up burden	Higher, nitrophenol removal and control needed	Lower, simple aqueous wash
Best suited to	Building-block workflows, bioconjugation, ADC linkers	One-pot amide, ester and cyclic carbamate formation

Industry Segments Served

ADC, bioconjugation and linker manufacturers.

API manufacturers producing carbamate- and urea-containing molecules.

CDMOs and contract synthesis organisations executing client-owned routes.

Peptide and peptidomimetic manufacturers.

PEG and polymer-conjugate producers.

Specialty polymer manufacturers polycarbonates and polyurethanes.

Technical Specifications

The parameters below represent our standard commercial specification. Customer-specific specifications can be agreed at enquiry stage.

Parameter	Specification
Chemical Name (IUPAC)	Bis(4-nitrophenyl) carbonate
Common Synonyms	BNPC; PNP carbonate; 4-Nitrophenyl carbonate; 4,4′-Dinitrodiphenyl carbonate; Carbonic acid bis(4-nitrophenyl) ester
CAS Number	5070-13-3
EC / EINECS Number	225-775-4
Molecular Formula	C₁₃H₈N₂O₇
Molecular Weight	304.21 g/mol
Appearance	Off-white to pale yellow crystalline powder
Assay / Purity	≥ 98.0% by HPLC
Identification	IR and/or HPLC retention conforms to reference standard
Melting Range	Available on request
Stage of Synthesis	Carbonylating and activating reagent / key starting material
Downstream Product	Activated carbamates and carbonates, ADC and PEG linkers, unsymmetrical ureas, peptide active esters
Residual 4-Nitrophenol	Available on request
Related Substances	Mono-substituted and hydrolysis-related species controlled to in-house limits; reported on COA
Water Content (Karl Fischer)	Available on request
Sulphated Ash / Residue on Ignition	Available on request
Elemental Impurities	Controlled; ICH Q3D statement supplied to support the buyer’s risk assessment
Residual Solvents	As per ICH Q3C
Solubility	Practically insoluble in water (hydrolyses on contact); soluble in dichloromethane, THF, DMF, acetonitrile and ethyl acetate
Storage Condition	Store refrigerated at 2 – 8 °C in tightly closed original packing, protected from light and moisture
Shelf Life	As stated on the batch COA, in unopened original packing under recommended storage
GHS Classification	Skin Irrit. 2, Eye Irrit. 2 – H315, H319. Consult the MSDS before handling
Transport Classification	Available on request

A Practical Note on Colour

Fresh, well-stored BNPC is off-white to very pale yellow.

A distinctly deeper yellow generally indicates that free 4-nitrophenol has formed through moisture ingress.

Colour is therefore a useful first-line indicator at goods-in, though it is not a substitute for the assay and nitrophenol results on the COA.

If material arrives visibly more yellow than expected, quarantine it and contact us before charging it into a batch.

Handling, Storage & Stability Guidance

BNPC is a comparatively benign solid to handle skin and eye irritation rather than acute toxicity or corrosivity but it is moisture-sensitive, and storage practice determines the quality of the material at the point of use.

Store refrigerated at 2 – 8 °C, tightly closed, protected from light and moisture.

Allow containers to reach room temperature before opening to prevent condensation on the powder.

Dispense under dry conditions and re-seal the inner liner immediately after each withdrawal; keep desiccant in place.

Charge into anhydrous solvent systems – water in the reaction solvent hydrolyses the reagent and releases nitrophenol into the product stream.

Use standard chemical-resistant gloves and eye protection; handle with dust control during weighing.

Keep away from strong bases, nucleophilic amines and moisture during storage.

Plan nitrophenol-bearing waste streams for appropriate treatment 4-nitrophenol is an aquatic toxicant and should not enter general effluent untreated.

Regulatory & Documentation Support

BNPC is a reagent and starting material, so a DMF or CEP does not apply to it as a standalone item.

What buyers need is documented evidence of controlled manufacture and an impurity picture their own filing can rest on.

Documentation Supplied

Certificate of Analysis (COA) – batch-specific, with every consignment.

Material Safety Data Sheet (MSDS) in GHS format, with destination-language versions on request.

Technical Data Package for GMP-grade material – manufacturing flow, analytical methods, specification rationale, impurity profile.

GMP Starting Material declaration under ICH Q7 principles, where the GMP grade is ordered.

Certificate of Origin, Non-GMO declaration, BSE/TSE-free and allergen statements.

ICH Q3C residual solvent and ICH Q3D elemental impurity statements.

Documentation support where BNPC is referenced as a starting material in the buyer’s DMF, ASMF or CEP dossier.

Site audit access, subject to prior scheduling and confidentiality agreement.

Packaging, MOQ & Logistics

Parameter	Details
Standard Packing	Sealed HDPE containers with double LDPE inner liner, desiccant-protected and light-protected, in outer fibre or HDPE drums
Pack Sizes	Available on request
Minimum Order Quantity	Available on request
Production Lead Time	Available on request
Monthly Capacity	Available on request
Sampling	Analytical and working samples readily available the mild hazard profile and absence of export control make sample supply straightforward for this product
Shipping Terms	FOB / CIF / CFR / EXW, as agreed
Mode of Transport	Sea freight; air freight availability available on request, subject to DG classification
Cold Chain	Refrigerated or insulated shipping with desiccant where destination and transit time require it
Port of Loading	Available on request
Export Documentation	Standard commercial documentation

Why Choose Us as Your BNPC Supplier

Moisture-Excluded Manufacturing and Packing

Hydrolysis is the sole significant degradation pathway for BNPC, and it is what generates the nitrophenol that matters downstream.

Moisture exclusion is designed into drying, milling and packing rather than checked only at release, and containers ship desiccant- and light-protected.

Straightforward Export Documentation

Responsive at Development Scale

Bioconjugation and ADC programmes rarely start with tonnage.

We quote and ship qualification-scale quantities without treating them as a nuisance order, because the programmes that succeed scale up with the supplier who was responsive at gram scale.

Frequently Asked Questions

Request a Quote for Bulk BNPC Supply

Share your required grade, quantity, specification and destination, and our export team will respond with pricing, lead time and the documentation set for Bis(4-nitrophenyl) carbonate (CAS 5070-13-3).