5H-Cyclopenta[H]quinazoline, 6,7,8,9-tetrahydro-7,7,8,9,9-pentamethyl- (CAS 1315251-11-6) — Woody Middle to base Note Fragrance Ingredient

Woody · Musky

5H-Cyclopenta[H]quinazoline, 6,7,8,9-tetrahydro-7,7,8,9,9-pentamethyl-

CAS 1315251-11-6

Origin
synthetic
Note
Middle to base
IFRA
Use with awareness
Data as of: Apr 2026

What Is 5H-Cyclopenta[H]quinazoline, 6,7,8,9-tetrahydro-7,7,8,9,9-pentamethyl-?

This synthetic fragrance ingredient is a specialized aromatic compound used in modern perfumery. Consumers may encounter it in niche or avant-garde fragrances seeking unique olfactory effects. As a synthetic molecule, it allows perfumers to create novel scent profiles not found in nature, contributing to innovative fragrance compositions that push creative boundaries.

Safety Profile

USE WITH AWARENESS
Generally safeUse with awarenessProfessional use
Used in commercial fragrance formulations
Limited safety data available
CAS
1315251-11-6
Formula
Mixture
MW
Variable
Odor Family
Woody · Musky
Layer 1 · Enthusiast

What Does 5H-Cyclopenta[H]quinazoline, 6,7,8,9-tetrahydro-7,7,8,9,9-pentamethyl- Smell Like?

This synthetic molecule offers a complex aromatic profile with intriguing facets. The scent evolves from an initial sharp, almost metallic top note to reveal a warm, woody-amber heart with subtle powdery undertones. In drydown, it leaves a persistent musky-balsamic trail with faint leathery nuances. The overall effect is modern and abstract, combining elements of clean musk with sophisticated woody-amber character.

Scent Profile
Layer 2

Chemistry, Properties & Perfumer Guide

The Chemistry

5H-Cyclopenta[H]quinazoline derivatives belong to the nitrogen-containing heterocyclic compounds class. The pentamethyl substitution pattern on the cyclopentaquinazoline core creates a sterically hindered structure that influences both volatility and odor characteristics. While specific synthesis routes are proprietary, such compounds are typically prepared through cyclization reactions of appropriately substituted precursors under controlled conditions.

Physical & Chemical Properties

Perfumer Guide

Note Position
Middle to base
Volatility
Moderate to low (hours)
Blending
Good
ApplicationTypical %RangeNotes
Fine Fragrance0.5-2%Up to 5%Modern woody-amber modifier
Functional Fragrance0.1-0.5%Up to 1%Long-lasting base note

Classic Accords

Tip: Use as a sophisticated woody-amber bridge between middle and base notes.

Alternatives & Comparisons

1
Ambroxan CAS 6790-58-5

For similar woody-amber character but with more transparency and diffusion.

2
Cashmeran CAS 33704-61-9

When seeking muskier facets with velvety texture.

Layer 3

Safety, Regulatory & Sustainability

⚠ Regulatory Disclaimer

General reference only. Consult current IFRA Standards Library before formulating.

IFRA Status

No specific IFRA restrictions currently listed.

RIFM Assessment

Not currently evaluated by RIFM.

Sustainability

As a synthetic material, this compound avoids natural resource depletion concerns. However, its environmental impact depends on manufacturing processes and energy inputs. The specialized nature of its production suggests moderate carbon footprint compared to commodity fragrance chemicals.

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References

    Data: PubChem (NIH), PubMed, RIFM, IFRA. Last reviewed: Apr 2026.

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