N-Isopropyl Tadalafil: Structure, Identity, and Analytical Reference

kimerachems

June 9, 2026

N-Isopropyl Tadalafil belongs to the tetrahydro-β-carboline (pyrazinopyridoindole-dione) class of PDE5-inhibitor scaffolds, and it shares the tadalafil core with a single structural change. Kimera supplies it strictly for research use only (RUO), so it carries no approval for human or veterinary use and serves no diagnostic or therapeutic purpose. This page covers its identity, its structure, and the analytical methods that confirm it.

Identity and Nomenclature

Property	Value
Common name	N-Isopropyl Tadalafil
Primary synonym	Isopropylnortadalafil
Other names	N-Isopropyl Nortadalafil; 2-Isopropyl tadalafil; 2-(propan-2-yl) tadalafil
CAS number	171596-30-8
Molecular formula	C24H23N3O4
Molecular weight	417.46 g/mol (avg)
Monoisotopic mass	417.169
Parent scaffold	Tadalafil (C22H19N3O4)
Class	PDE5-inhibitor analog (tetrahydro-β-carboline)

IUPAC name: (6R,12aR)-6-(1,3-benzodioxol-5-yl)-2-(propan-2-yl)-2,3,6,7,12,12a-hexahydropyrazino[1′,2′:1,6]pyrido[3,4-b]indole-1,4-dione

Structural Relationship to Tadalafil

N-Isopropyl Tadalafil differs from tadalafil at just one position. Specifically, an N-isopropyl group replaces the N-methyl group on the terminal nitrogen of the piperazinedione (diketopiperazine) ring, while the benzodioxole and indole portions stay unchanged. Because of this single swap, the formula gains C2H4 and shifts from C22H19N3O4 to C24H23N3O4, a mass increase of 28.05. The scaffold also keeps the (6R,12aR) configuration as its reference, so analogs with different stereochemistry count as distinct compounds, and each one needs independent characterization.

Analytical Characterization

N-Isopropyl Tadalafil sits very close, both structurally and by mass, to several other tadalafil derivatives: Nortadalafil, the N-ethyl and N-propyl homologs, and the hydroxyalkyl variants. As a result, a single assay rarely settles its identity, so labs combine orthogonal methods:

HPLC / HPLC-DAD measures purity and separates the compound from related analogs.
LC-HRMS confirms the C24H23N3O4 formula (monoisotopic 417.169) and maps the fragmentation pattern.
NMR pins down the N-isopropyl group and tells it apart from the N-methyl, N-ethyl, N-propyl, and N-hydroxyalkyl variants that often co-elute or share a nominal mass.

One point matters most here: mass alone cannot resolve the N-substituent. The N-propyl isomer carries the same formula and nearly the same mass, so NMR becomes the deciding method. Every lot therefore ships with third-party COA verification that documents identity and purity.

Literature Context

Analysts first described N-Isopropyl Tadalafil in the analytical literature, and they coined the name isopropylnortadalafil, after they isolated it from consumer products and then elucidated its structure by LC-HRMS and NMR. Today it appears mainly in forensic and pharmaceutical-analysis work that tracks designer PDE5-inhibitor analogs. This history explains why careful confirmation matters so much: vendors easily mislabel or substitute compounds in this series, so a competent lab verifies identity directly rather than trusting a supplier label.

N-Isopropyl Tadalafil belongs to Kimera’s Analytical Reagents lineup of tadalafil analogs. Researchers who compare analogs across this series often also examine Nortadalafil, Aminotadalafil, and N-ethyl Tadalafil, since each keeps the tetrahydro-β-carboline core but differs at the N2 position or in ring substitution. For background on how labs confirm analog identity.

Handling and Storage

N-Isopropyl Tadalafil ships as a solid powder, much like tadalafil itself, which forms a white crystalline solid. Store it sealed and shield it from light and moisture, and for long-term storage keep the solid at -20°C. Because the tadalafil scaffold dissolves poorly in water, researchers usually prepare stock solutions in an organic solvent such as DMSO. Always confirm lot-specific guidance against the accompanying COA.

Availability

You will find lot-specific COAs, purity data, and current pricing on the N-Isopropyl Tadalafil product page, which Kimera opens to registered account holders.

Research Use Only

Kimera sells N-Isopropyl Tadalafil only for in-vitro laboratory research. It is not a dietary supplement, a drug, or a medical product, and it must not enter any human or animal use.tution guidance against the accompanying COA.

Research Use Only
All products supplied by Kimera Chems LLC are intended strictly for laboratory research use. They are not drugs, dietary supplements, food, cosmetics, or veterinary products, and are not for human or animal consumption.

Regulatory Status
Kimera Chems LLC is a chemical supplier. Kimera Chems is not a compounding pharmacy or chemical compounding facility as defined under Section 503A of the Federal Food, Drug, and Cosmetic Act, and is not an outsourcing facility as defined under Section 503B of that Act.

Intended Use and Handling
The products we offer are not intended for human use. They are intended for in-vitro and pre-clinical research purposes only. The customer acknowledges that risks exist in the handling, use, and distribution of these products, and certifies that it has the proper equipment, facilities, and personnel to manage those risks, and knowingly accepts them. These chemicals are not intended to be used, and should not be used, in inappropriate applications — including, without limitation, as food additives, drugs, cosmetics, or household chemicals, or in any application outside of in-vitro laboratory research, pre-clinical research, or laboratory chemical synthesis and materials testing.

Customer Responsibility
By purchasing these products, the customer agrees to the above. In the event the customer uses, or causes others to use, these products outside of these restrictions, the customer accepts all risk of doing so, absolves Kimera Chems of any responsibility for such actions, and agrees to indemnify and hold Kimera Chems harmless against any third-party claims arising from them.