Nopol

• CAS: 35836-73-8
• Catalog Number: ACM35836738
• Category: Main Products
• Molecular Weight: 166.26
• Molecular Formula: C₁₁H₁₈O
• Synonyms: AZD7687
• IUPAC Name: 2-[(1S,5R)-6,6-dimethyl-4-bicyclo[3.1.1]hept-3-enyl]ethanol
• SMILES: CC1(C2CC=C(C1C2)CCO)C
• InChI Key: ROKSAUSPJGWCSM-UWVGGRQHSA-N
• Boiling Point: 230ºC
• Flash Point: 98.9ºC
• Density: 0.978g/cm³
• Appearance: colorless viscous liquid
• EC Number: 252-744-2
• Exact Mass: 166.13600
• Hazard Statements: Xn: Harmful
• Safety Description: 26-37/39

Case Study

Synthesis of Nopol-Based Cationic Photopolymerizable Polysiloxane Oxacyclobutanes

Hu Y, et al. Progress in Organic Coatings, 2022, 163, 106681.

In this study, a series of bio-based cationic photopolymerizable polysiloxane oxacyclobutanes, derived from nopol with varying silicone chain lengths (Nopol-Sin, n = 3, 6, 9), were synthesized.
The synthesis procedure for Nopol-Sin is as follows:
First, a mixture of 9.6 g (240 mmol) NaH and paraffin wax (with NaH content at 60 wt%) was washed with 50 mL petroleum ether to remove the paraffin. The NaH was then added to a three-necked flask containing 150 mL anhydrous tetrahydrofuran (THF). Next, 200 mmol of nopol and 220 mmol of 3-ethyl-3-chloromethyloxybutane were introduced into the flask, and the mixture was stirred thoroughly before being heated to 50°C under reflux. After 6 hours of reaction, 50 mL of water was added to quench the reaction, and the solvent was removed using a rotary evaporator. The reaction mixture was then extracted three times with 100 mL ethyl acetate. The organic phase was washed three times with 50 mL water, followed by the addition of anhydrous magnesium sulfate, and the mixture was stirred overnight. Finally, the fraction collected at 140-150°C under reduced pressure via rotary evaporation yielded Intermediate 1.
Next, a three-necked flask equipped with a drop funnel, thermometer, and reflux condenser was purged with nitrogen three times. 20 mmol of Intermediate 1 and 40 mL of anhydrous toluene were added to the flask, followed by 1.32 g (for Si₃H), 2.32 g (for Si₆H), or 3.32 g (for Si₉H) of Karstedt catalyst (at a concentration of 100 ppm). After heating the mixture to 55°C, 20 mmol of hydrogen-containing methylsilicone oil was introduced into the reaction solution. The reaction proceeded at 90°C for 4 hours, completing the reaction. Finally, the solvent was removed under vacuum to obtain the desired Nopol-Sin product.

Synthetic Precursor, Broad-Spectrum Antifungal and 3D-QSAR Predictable Properties of Nopol

Chen M, Duan WG, Lin GS, et al. Molecules, 2021, 26(6):1708.

The synthetic versatility and plant pathogen inhibitory bioactivities of nopol (2-(6,6-dimethylbicyclo[3.1.1]hept-2-enyl)ethanol, derived from β-pinene Prins condensation) were studied via multi-step heterocyclic synthesis and in vitro mycelial growth inhibition assays. Its bicyclic terpene skeleton with reactive hydroxyl and C=C double bonds serves as the core parent scaffold for constructing 1,3,4-thiadiazole-thiourea hybrid antifungal molecules, whose steric and electrostatic molecular features determine pathogen suppression potency.
Nopol exhibited outstanding multi-step heterocyclic synthetic precursor activity for agrochemical fungicides: Starting from raw β-pinene feedstock, nopol was first obtained via ZnCl₂-catalyzed Prins reaction at 110 °C with 60% isolation yield; sequential Dess-Martin oxidation, thiosemicarbazide condensation and iodine-mediated ring closure converted nopol into 5-nopyl-2-amino-1,3,4-thiadiazole key intermediate at 65% cyclization yield, followed by nucleophilic addition with diverse substituted isothiocyanates to afford 18 target thiourea derivatives with 45-70% product recovery. It demonstrated potent broad-spectrum antifungal effects against eight common crop pathogenic fungi at 50 μg/mL test concentration: All nopol-derived hybrid compounds produced average mycelial inhibition rates over 64% against Physalospora piricola, Cercospora arachidicola and Alternaria solani; Compound 6j (m,p-dichlorophenyl substituent) synthesized from nopol achieved overall average 51.9% inhibition across all eight test pathogens, while nopol parent raw material only delivered weak fungistatic activity below 25% inhibition rate. Additionally, nopol-derived fungicidal molecules displayed quantifiable structure-activity relationships predictable by 3D-QSAR CoMFA modeling: Steric field contributed 52.9% and electrostatic field contributed 47.1% to antifungal potency variance; meta/para halogen-substituted phenyl groups grafted onto nopol-thiadiazole-thiourea skeleton enlarged molecular dipole moment (6j reached 8.2789 D vs parent nopol analog 6a at 5.7380 D), significantly lifting inhibitory efficiency-6c and 6q recorded 86.1% inhibition against apple ring rot P. piricola, superior to commercial chlorothalonil positive control at 75.0% inhibition. Mycelium morphological observation revealed nopol hybrid derivatives disrupted fungal hyphal elongation and cell wall formation, while unmodified nopol barely interfered with pathogen vegetative growth. These studies demonstrate that nopol possesses valuable terpene heterocyclic synthetic precursor, broad-spectrum crop antifungal and CoMFA 3D-QSAR predictable structural activity properties for botanical agrochemical development.
The synthetic and antifungal evaluation experiment was separated into terpene synthesis batches, heterocyclic derivatization groups and in vitro pathogen inhibition test groups. Nopol synthesis adopted β-pinene and paraformaldehyde raw materials with Lewis acid catalysis, followed by four-step sequential oxidation, condensation, cyclization and thiourea formation to generate 18 nopol-based target molecules with distinct aromatic/alkyl terminal substituents. For antifungal testing, eight plant pathogenic strains (Fusarium oxysporum f. sp. cucumerinum, Cercospora arachidicola, Physalospora piricola, Alternaria solani, Gibberella zeae, Rhizoctonia solani, Bipolaris maydis, Colleterichum orbicalare) were cultured on PSA medium; 50 μg/mL compound solutions prepared with acetone emulsifier were added to culture plates, mycelial expansion diameters measured after 48 h to calculate relative inhibition percentage, chlorothalonil set as positive control and blank solvent as negative blank. CoMFA 3D-QSAR modeling used 15 training-set nopol derivatives and one test compound, ED activity coefficient as dependent variable, Tripos force field for geometric optimization, cross-validation q² and non-cross-validation r² calculated to verify model predictability, contour maps analyzed steric/electrostatic substitution rules. One-way ANOVA was used to compare inhibition rate differences between nopol parent and its hybrid derivatives at α=0.05 significance threshold. The results verified nopol's dual reactive functional groups enable modular construction of high-efficiency terpene antifungal agents, and phenyl halogen substitution optimizes steric-electrostatic characteristics to strengthen pathogen growth suppression capacity.

Biobased Precursor, High Photoreactive and Thermally Tunable Cycloaliphatic Epoxy Properties of Nopol

Ortiz R A, Valdez A E G, Cruz D H, et al. Journal of Polymer Research, 2020, 27(1):144.

The synthetic derivatization and photopolymerization performance of nopol (2-(6,6-dimethylbicyclo[3.1.1]hept-2-enyl)ethanol, a renewable terpene monomer converted from β-pinene) were studied via multi-step epoxy synthesis, RT-FTIR kinetic tracking and thermal characterization tests. Its unique bicyclic skeleton equipped with terminal hydroxyl and endocyclic C=C double bonds serves as the core reactive scaffold to fabricate three distinct cycloaliphatic epoxy monomers, whose crosslinking reactivity and thermal behavior are governed by different linking backbones (glycidyl ether, triazine, acetal).
Nopol exhibited excellent biobased epoxy precursor activity via three modular synthetic routes: Route 1 epoxidized nopol's hydroxyl with epichlorohydrin to produce bifunctional epoxy N1 at 90% total yield; Route 2 realized tris-nopol grafting onto cyanuric chloride aromatic core to afford triazine-based trifunctional epoxy N2 with 70% epoxidation yield; Route 3 constructed dual-nopol acetal intermediate with cyclohexene dialdehyde, then full oxidation to generate acetal-type trifunctional epoxy N3 at 72% purification yield. All nopol-derived epoxies carried highly strained oxirane rings fused on bicyclic terpene units, delivering remarkable cationic photopolymerization reactivity under 50 mW/cm² UV irradiation: After 600 s continuous UV exposure, bifunctional N1 reached maximum epoxy group conversion of 62%, while trifunctional N3 and N2 achieved 54% and 58% conversion respectively, with N3 showing the fastest initial crosslinking rate at the early UV stage. It demonstrated adjustable thermal mechanical properties determined by backbone structure difference: After UV bulk curing, N1 crosslinked polymer displayed low glass transition temperature (Tg = 12 °C) with loose network and 214 °C thermal decomposition onset; Triazine-linked N2 resin owned the highest Tg (66 °C) and superior thermal stability with 302 °C 5% weight loss temperature; Acetal-bridged N3 had medium Tg at 61 °C and intermediate thermal onset of 268 °C. Additionally, gel fraction measurements confirmed nopol epoxy crosslinking completeness: N1 polymer attained 90% gel content after post-UV dark cationic polymerization, surpassing N2 (82%) and N3 (80%) crosslinked films. TGA thermogram analysis indicated the aromatic triazine rigid segment in N2 effectively suppressed thermal chain scission compared to acetal flexible linkages and simple glycidyl ether chains derived from nopol. These studies demonstrate that nopol possesses valuable renewable epoxy synthetic precursor, fast cationic photopolymerization reactivity and backbone-dependent tunable thermal mechanical properties for low-VOC outdoor biocoating materials.
The nopol epoxy synthesis and photothermal characterization experiment was separated into three synthetic batches (N1, N2, N3), UV curing kinetic groups and thermal analysis test groups. For monomer preparation, nopol starting material reacted with epichlorohydrin, cyanuric chloride and cyclohexene carboxaldehyde respectively under controlled temperature and catalysis, followed by Oxone-mediated neutral epoxidation of all alkene double bonds to form fully oxirane-functionalized monomers. Cationic photocuring formulations contained each pure nopol epoxy mixed with 4 mol% DPPI iodonium photoinitiator; RT-FTIR monitored epoxy band absorbance decay at 857 cm⁻¹ every second over 600 s UV irradiation to calculate crosslink conversion curves. Bulk cured polymer specimens (35 mm × 10 mm × 2 mm) were manufactured in UV chamber for 30 min at 40 mW/cm², then subjected to DSC scanning (-50 to 150 °C, 10 °C/min) to record Tg and TGA thermal ramp (30 to 600 °C) to measure degradation onset temperature. Gel content was quantified by 24 h chloroform Soxhlet extraction following ASTM D2765 standard, one-way ANOVA was used to compare conversion, Tg and thermal onset differences of three nopol epoxy polymers at α=0.05 significance threshold. The results verified that nopol's dual reactive functional groups enable diversified design of photoreactive cycloaliphatic epoxies, and aromatic triazine linking architecture significantly enhances the thermal stability of nopol-based crosslinked coating resins.

Custom Q&A

What is the molecular formula of Nopol?

The molecular formula of Nopol is C11H18O.

What is the IUPAC name of Nopol?

The IUPAC name of Nopol is 2-(6,6-dimethyl-2-bicyclo[3.1.1]hept-2-enyl)ethanol.

What is the InChI of Nopol?

The InChI of Nopol is InChI=1S/C11H18O/c1-11(2)9-4-3-8(5-6-12)10(11)7-9/h3,9-10,12H,4-7H2,1-2H3.

What is the InChIKey of Nopol?

The InChIKey of Nopol is ROKSAUSPJGWCSM-UHFFFAOYSA-N.

What is the canonical SMILES representation of Nopol?

The canonical SMILES representation of Nopol is CC1(C2CC=C(C1C2)CCO)C.

What is the CAS number of Nopol?

The CAS number of Nopol is 128-50-7.

What is the molecular weight of Nopol?

The molecular weight of Nopol is 166.26g/mol.

How many hydrogen bond donors are there in Nopol?

Nopol has 1 hydrogen bond donor.

How many hydrogen bond acceptors are there in Nopol?

Nopol has 1 hydrogen bond acceptor.

What is the topological polar surface area of Nopol?

The topological polar surface area of Nopol is 20.2Ų.