481-42-5

Basic information

• Product Name: PLUMBAGIN
• Synonyms: plumbagone;Plumbagin from Plumbago indica;Plumbagin,95%;1,4-Dihydro-1,4-dioxo-5-hydroxy-2-methylnaphthalene;Plumbagin (natural);PLUMBAGIN PRACTICAL GRADE;Plumbagin, 99+%;PLUMBAGIN(RG)
• CAS NO: 481-42-5
• Molecular Formula: C₁₁H₈O₃
• Molecular Weight: 188.18
• EINECS: 207-569-6
• Product Categories: Anthraquinones, Hydroquinones and Quinones;Inhibitors
• Mol File: 481-42-5.mol
• Article Data: 31

Chemical Properties

• Melting Point: 76-78 °C(lit.)
• Boiling Point: 283.17°C (rough estimate)
• Flash Point: 200.165 °C
• Appearance: Orange/Crystals or Crystalline Powder
• Density: 1.354
• Vapor Pressure: 1.92E-06mmHg at 25°C
• Refractive Index: 1.6310 (estimate)
• Storage Temp.: −20°C
• Solubility: very faint turbidity in hot Methanol
• PKA: 6.70±0.20(Predicted)
• Merck: 7538
• CAS DataBase Reference: PLUMBAGIN(CAS DataBase Reference)
• NIST Chemistry Reference: PLUMBAGIN(481-42-5)
• EPA Substance Registry System: PLUMBAGIN(481-42-5)

Safety Data

• Hazard Codes: T
• Statements: 25-34-36/37/38
• Safety Statements: 22-26-36/37/39-45-37/39-28A
• RIDADR: UN 2923 8/PG 2
• WGK Germany: 3
• RTECS: QL8500000
• HazardClass: 6.1(a)
• PackingGroup: II
• Hazardous Substances Data: 481-42-5(Hazardous Substances Data)

Usage

Description

Plumbagin is a natural 1,4-naphthoquinone first isolated from plants of the genus Plumbago. It has diverse effects in cells and animals. Plumbagin causes the generation of reactive oxygen species and induces apoptosis in cancer cells. It activates signaling through Nrf2 and the antioxidant response element, inducing the expression of Nrf2 target genes, including NQO1 and heme oxygenase-1 in cultured neuronal cells. Plumbagin also inhibits NADPH oxidase 4 in a time- and dose-dependent manner. It can be protective against peroxide stress or deprivation of glucose or oxygen.

Chemical Properties

ORANGE CRYSTALLINE POWDER OR CRYSTALS

Uses

Different sources of media describe the Uses of 481-42-5 differently. You can refer to the following data:
1. antibacterial, antifungal, tuberculostatic; antifeedant (worm)
2. Plumbagin from Plumbago indica has been used: as a reactive oxygen species agent (ROS) to induce cytotoxicity in mouse embryonic fibroblastsas an oxidative stress inducer to generate superoxide anion in Saccharomyces cerevisiaeas a reference standard in thin layer chromatography and in spectrophotometric analysis for quantification of plumbagin in Plumbago auriculate samples

Definition

ChEBI: A hydroxy-1,4-naphthoquinone that is 1,4-naphthoquinone in which the hydrogens at positions 2 and 5 are substituted by methyl and hydroxy groups, respectively.

General Description

Plumbagin is a bioactive naphthoquinone present majorly in Plumbago indica L. It is a quinoid and is also derived from the roots of Plumbago zeylanica?roots.

Biochem/physiol Actions

Plumbagin exhibits various pharmacological activities including antimicrobial, anticancer, anti-atherosclerotic, antidiabetic, anti-inflammatory, hypolipidemic, and neuroprotective activities. It inhibits the signal transducer and activator of transcription 3 (STAT3) signaling and halts the proliferation of esophageal squamous cell carcinoma (ESCC). Plumbagin elicits protective antioxidative functionality in 4-nitroquinoline-N-oxide (NQNO) induced stress in lymphoma. Plumbagin in a nanoemulsion formulation has antiproliferative effect towards prostate cancer.

in vitro

plumbagin exhibited effective cell growth inhibition via inducing cancer cells to undergo g2/m phase arrest and apoptosis. blockade of cell cycle was associated with increased levels of p21 and reduced amounts of cdc2, cdc25c and cyclinb1. plumbagin treatment also found to enhance the levels of inactivated phosphorylated cdc2 and cdc25c. blockade of p53 activity partially decreased plumbagin-induced apoptosis and g2/m arrest, indicating it might be operated by p53-dependent and independent pathway [1].

in vivo

to determine whether plumbagin inhibited the in vivo tumor growth, a549 cells were injected into nude mice. tumor growth inhibition was most evident in mice treated with plumbagin at 2 mg/kg/day, where around 80% reductions in tumor size were observed, in contrast with mice treated with the vehicle. no sign of toxicity was observed in plumbagin-treated mice as judged by monitoring body weight [1].

IC 50

11.69 μm for a549 cells

Purification Methods

It crystallises in yellow needles from aqueous EtOH. It is soluble in organic solvents, it is steam volatile and it sublimes on heating in a vacuum. [Fieser & Dunn J Am Chem Soc 58 572 1936, Beilstein 8 III 2576, 8 IV 2376.]

references

[1] hsu yl,cho cy,kuo pl,huang yt,lin cc. plumbagin (5-hydroxy-2-methyl-1,4-naphthoquinone) induces apoptosis and cell cycle arrest in a549 cells through p53 accumulation via c-jun nh2-terminal kinase-mediated phosphorylation at serine 15 in vitro and in vivo. j pharmacol exp ther.2006 aug;318(2):484-94.

InChI:InChI=1/C11H8O3/c1-6-5-9(13)10-7(11(6)14)3-2-4-8(10)12/h2-5,12H,1H3

Synthetic route

2-bromo-5-hydroxy-[1,4]naphthoquinone (69008-03-3) + tetramethylstannane (594-27-4) → 5-hydroxy-2-methyl-1,4-naphthoquinone (481-42-5)

Conditions	Yield
tetrakis(triphenylphosphine) palladium(0); copper(I) bromide In 1,4-dioxane for 15h; Heating;	100%
tetrakis(triphenylphosphine) palladium(0); copper(I) bromide In 1,4-dioxane for 15h; Heating; Yield given;

6-methyl-5,8-dioxo-5,8-dihydronaphthalen-1-yl acetate (116752-29-5) → 5-hydroxy-2-methyl-1,4-naphthoquinone (481-42-5)

Conditions	Yield
With hydrogenchloride In methanol at 50℃; for 1h;	100%

5-methoxymethoxy-2-methyl-1,4-naphthoquinone (106914-49-2) → 5-hydroxy-2-methyl-1,4-naphthoquinone (481-42-5)

Conditions	Yield
With toluene-4-sulfonic acid In neat (no solvent, solid phase) at 20℃; for 0.583333h; Green chemistry;	97%
With hydrogenchloride In methanol for 0.0833333h; Heating;	95%

2,2,5-trimethylnaphtho-[1,8-de]-1,3-dioxin-6-ol → 5-hydroxy-2-methyl-1,4-naphthoquinone (481-42-5)

Conditions	Yield
With cerium(IV) ammonium sulphate In water; acetonitrile for 0.25h; Cooling with ice;	95%
With ammonium cerous sulfate In water; acetonitrile at 0℃; for 0.25h;	95%

2-methyl-5-methoxy-1,4-naphthoquinone (22266-99-5) → 5-hydroxy-2-methyl-1,4-naphthoquinone (481-42-5)

Conditions	Yield
With aluminium trichloride	90%
With aluminium trichloride In dichloromethane 1.) 1 h, room temp., 2.) 15 min, water;	90%
With aluminium trichloride In dichloromethane at 20℃; for 2h;	75%

diomuscinone → 5-hydroxy-2-methyl-1,4-naphthoquinone (481-42-5)

Conditions	Yield
With sodium hydride In tetrahydrofuran for 15h; Ambient temperature;	82%

2-Methyl-1,5-naphthalindiol-5-acetat (116752-27-3) → 5-hydroxy-2-methyl-1,4-naphthoquinone (481-42-5)

Conditions	Yield
With oxygen; methylene blue In methanol at 20℃; for 4h; Irradiation;	69%
Multi-step reaction with 2 steps 1: 74 percent / aq. ON(SO3K)2, KH2PO4 / methanol / 2 h 2: 100 percent / conc. HCl / methanol / 1 h / 50 °C View Scheme

menadione (58-27-5) → 5-hydroxy-2-methyl-1,4-naphthoquinone (481-42-5)

Conditions	Yield
With [ruthenium(II)(η6-1-methyl-4-isopropyl-benzene)(chloride)(μ-chloride)]2; trifluoroacetic acid; trifluoroacetic anhydride; bis-[(trifluoroacetoxy)iodo]benzene at 80℃; for 12h; Sealed tube; chemoselective reaction;	61%
With ammonium peroxydisulfate; sulfuric acid

5-acetyloxy-3-bromo-2-methyl-1,4-naphthoquinone (101927-36-0) + Bu3SnH → 5-hydroxy-2-methyl-1,4-naphthoquinone (481-42-5)

Conditions	Yield
at 145℃; for 12h;	60%

1,8-Dihydroxy-3-methylnaphthalin (1130-61-6) → 5-hydroxy-2-methyl-1,4-naphthoquinone (481-42-5) + 7-methyljuglone (14787-38-3)

Conditions	Yield
With salcomine; oxygen In N,N-dimethyl-formamide at 20℃; for 1h; Inert atmosphere;	A 51% B 30%

2-bromo-5-hydroxy-[1,4]naphthoquinone (69008-03-3) + <2,6-dimethoxy-4-methylphenyl>trimethylstannane (126421-39-4) → 5-hydroxy-2-methyl-1,4-naphthoquinone (481-42-5) + 2-(2,6-Dimethoxy-4-methylphenyl)-5-hydroxy-1,4-naphthoquinone (137057-03-5)

Conditions	Yield
tetrakis(triphenylphosphine) palladium(0) In 1,4-dioxane for 3h; Heating;	A 6% B 46%

2-bromo-5-hydroxy-[1,4]naphthoquinone (69008-03-3) + lithium dimethylcuprate (15681-48-8) → 5-hydroxy-2-methyl-1,4-naphthoquinone (481-42-5)

Conditions	Yield
In tetrahydrofuran at -78℃;	42%

1-methoxy-2-methyl-4,5-naphthylene diacetate (848141-72-0) → 5-hydroxy-2-methyl-1,4-naphthoquinone (481-42-5) + 8,8'-dihydroxy-3,3'-dimethyl[2,2']binaphthalenyl-1,4,1',4'-tetraone (34341-27-0)

Conditions	Yield
Stage #1: 1-methoxy-2-methyl-4,5-naphthylene diacetate With potassium hydroxide In methanol for 0.5h; Heating; Stage #2: With lead dioxide In chloroform for 0.5h; Heating;	A 23% B 0.3%

1,5-Dihydroxy-2-methylnaphthalin (79786-99-5) → 5-hydroxy-2-methyl-1,4-naphthoquinone (481-42-5) + 5-hydroxy-6-methyl-1,4-naphthoquinone (60011-38-3)

Conditions	Yield
With potassium dihydrogenphosphate; potassium nitrososulfonate In methanol for 2h;	A n/a B 15%
With potassium dihydrogenphosphate; potassium nitrososulfonate In methanol for 2h;	A n/a B 15%

(3R,4R)-4,8-dihydroxy-3-methyl-3,4-dihydro-1(2H)-naphthalenone (39626-94-3, 72058-77-6, 92694-13-8, 39626-91-0) → 5-hydroxy-2-methyl-1,4-naphthoquinone (481-42-5) + 1,2(3)-tetrahydro-3,3'-biplumbagin

Conditions	Yield
With 2,3-dicyano-5,6-dichloro-p-benzoquinone In 1,4-dioxane for 12h; Heating;	A n/a B 0.005%
With 2,3-dicyano-5,6-dichloro-p-benzoquinone In 1,4-dioxane for 12h; Heating;

ethanol (64-17-5) + 5-hydroxy-2-methyl-[1,4]naphthoquinone; compound with hydroquinone → 5-hydroxy-2-methyl-1,4-naphthoquinone (481-42-5) + hydroquinone (123-31-9)

ethanol (64-17-5) + 5-hydroxy-2-methyl-[1,4]naphthoquinone; compound with naphthol-(1) → α-naphthol (90-15-3) + 5-hydroxy-2-methyl-1,4-naphthoquinone (481-42-5)

2-methyl-1,4,5-naphthalenetriol (58274-93-4) → 5-hydroxy-2-methyl-1,4-naphthoquinone (481-42-5)

Conditions	Yield
With dihydrogen peroxide

5-hydroxy-2-methyl-[1,4]naphthoquinone; compound with hydroquinone + acetic acid (64-19-7) → 5-hydroxy-2-methyl-1,4-naphthoquinone (481-42-5) + hydroquinone (123-31-9)

5-hydroxy-2-methyl-[1,4]naphthoquinone; compound with naphthol-(1) + acetic acid (64-19-7) → α-naphthol (90-15-3) + 5-hydroxy-2-methyl-1,4-naphthoquinone (481-42-5)

(3R,4R)-4,8-dihydroxy-3-methyl-3,4-dihydro-1(2H)-naphthalenone (39626-94-3, 72058-77-6, 92694-13-8, 39626-91-0) → 5-hydroxy-2-methyl-1,4-naphthoquinone (481-42-5)

Conditions	Yield
With 2,3-dicyano-5,6-dichloro-p-benzoquinone In 1,4-dioxane for 18h; Heating;	22 mg
With pyridine; chromium(VI) oxide In chloroform for 24h;

plumbazeylanone (94410-15-8) → 5-hydroxy-2-methyl-1,4-naphthoquinone (481-42-5) + methylene-3,3'-diplumbagin (58275-00-6)

Conditions	Yield
at 240℃; under 4.5 Torr; for 0.0833333h;

(4aR,5R,8aR)-4a-Chloro-2-methyl-5-trimethylsilanyloxy-4a,5,8,8a-tetrahydro-[1,4]naphthoquinone → 5-hydroxy-2-methyl-1,4-naphthoquinone (481-42-5)

Conditions	Yield
With chromium(VI) oxide; acetic acid for 1.5h; Heating; Yield given;

5-hydroxynaphtho-1,4-quinone (481-39-0) + acetic acid (64-19-7) → 5-hydroxy-2-methyl-1,4-naphthoquinone (481-42-5) + isoplumbagin (14777-17-4) + 2,3-dimethyl-5-hydroxy-1,4-naphthoquinone (80596-51-6)

Conditions	Yield
With ammonium peroxydisulfate; silver nitrate 1.) Acetonitril, 80 deg C, 2.) H2O, Rueckfluss, 2 h; Multistep reaction;

1,4,5-Triacetoxy-8-chlor-2-methylnaphthalin (89475-06-9) → 5-hydroxy-2-methyl-1,4-naphthoquinone (481-42-5)

Conditions	Yield
Yield given. Multistep reaction;

2-methyl-5-amino-1,4-naphthoquinone (116415-35-1) → 5-hydroxy-2-methyl-1,4-naphthoquinone (481-42-5)

Conditions	Yield
With nitrosylsulfuric acid; sulfuric acid; water 1.) 4 h, 2.) 2 h, reflux; Yield given. Multistep reaction;
Multi-step reaction with 2 steps 1: 48 percent / NaNO2 / 3 h / Heating 2: 1.) ON(SO3K)2, 0.167 M K2HPO4, 2.) H2O / 1.) 4 h, 2.) 2 h, reflux View Scheme

5-Acetamido-2-methyl-1,4-naphthochinon (116415-36-2) → 5-hydroxy-2-methyl-1,4-naphthoquinone (481-42-5)

Conditions	Yield
With dipotassium hydrogenphosphate; potassium nitrososulfonate; water 1.) 4 h, 2.) 2 h, reflux; Yield given. Multistep reaction;

(S)-4,8-Dihydroxy-3-methyl-3,4-dihydro-2H-naphthalen-1-one → 5-hydroxy-2-methyl-1,4-naphthoquinone (481-42-5)

Conditions	Yield
With 2,3-dicyano-5,6-dichloro-p-benzoquinone In 1,4-dioxane for 8h; Heating;

(-)-5-hydroxy-2-methyl-2,3-dihydro-1,4-naphthoquinone → 5-hydroxy-2-methyl-1,4-naphthoquinone (481-42-5)

Conditions	Yield
With chromium(VI) oxide; sulfuric acid In sodium hydroxide for 0.0333333h;	12 mg

rel-(10S,1S,4R,4aS,9aR)-5,10-Dihydroxy-5,10-di-O-isopropylidene-1,4-methano-9a-methyl-9-oxo-1,4,4a,9,9a,10-hexahydroanthracene → 5-hydroxy-2-methyl-1,4-naphthoquinone (481-42-5)

Conditions	Yield
With hydrogenchloride; iron(III) chloride 1.) toluene, 270 deg C, 30 min, 2.) MeOH, 3 h; Yield given. Multistep reaction;

5-hydroxy-2-methyl-1,4-naphthoquinone (481-42-5) + methyl iodide (74-88-4) → 2-methyl-5-methoxy-1,4-naphthoquinone (22266-99-5)

Conditions	Yield
With silver(l) oxide In dichloromethane at 20℃; for 48h; Inert atmosphere;	99%
With silver(l) oxide	94%
With silver(l) oxide In chloroform Ambient temperature;	93%

5-hydroxy-2-methyl-1,4-naphthoquinone (481-42-5) + n-hexadecanoyl chloride (112-67-4) → plumbagin palmitate

Conditions	Yield
Stage #1: 5-hydroxy-2-methyl-1,4-naphthoquinone With triethylamine In diethyl ether at 20℃; for 0.5h; Stage #2: n-hexadecanoyl chloride In diethyl ether at 20℃; for 1h;	99%

n-dodecanoyl chloride (112-16-3) + 5-hydroxy-2-methyl-1,4-naphthoquinone (481-42-5) → 5-dodecanoyloxy-2-methyl-1,4-naphthoquinone

Conditions	Yield
Stage #1: 5-hydroxy-2-methyl-1,4-naphthoquinone With triethylamine In diethyl ether at 20℃; for 0.5h; Stage #2: n-dodecanoyl chloride In diethyl ether at 20℃; for 1h;	98%

5-hydroxy-2-methyl-1,4-naphthoquinone (481-42-5) + tetradecanoyl chloride (112-64-1) → plumbagin myristate

Conditions	Yield
Stage #1: 5-hydroxy-2-methyl-1,4-naphthoquinone With triethylamine In diethyl ether at 20℃; for 0.5h; Stage #2: tetradecanoyl chloride In diethyl ether at 20℃; for 1h;	98%

5-hydroxy-2-methyl-1,4-naphthoquinone (481-42-5) + Stearoyl chloride (112-76-5) → 5-octadecanoyloxy-2-methyl-1,4-naphthoquinone

Conditions	Yield
Stage #1: 5-hydroxy-2-methyl-1,4-naphthoquinone With triethylamine In diethyl ether at 20℃; for 0.5h; Stage #2: Stearoyl chloride In diethyl ether at 20℃; for 1h;	96%

(Z)-9-octadecenoyl chloride (112-77-6) + 5-hydroxy-2-methyl-1,4-naphthoquinone (481-42-5) → 5-{(Z)-octadecenylalkanoyloxy}-2-methyl-1,4-naphthoquinone

Conditions	Yield
Stage #1: 5-hydroxy-2-methyl-1,4-naphthoquinone With triethylamine In diethyl ether at 20℃; for 0.5h; Stage #2: (Z)-9-octadecenoyl chloride In diethyl ether at 20℃; for 1h;	96%

5-hydroxy-2-methyl-1,4-naphthoquinone (481-42-5) + acetic anhydride (108-24-7) → 6-methyl-5,8-dioxo-5,8-dihydronaphthalen-1-yl acetate (116752-29-5)

Conditions	Yield
With pyridine for 2h; Ambient temperature;	94%
With pyridine at 20℃; for 10h;	93%
With pyridine at 20℃; for 4h;	90%
With triethylamine In diethyl ether at 20℃; for 0.5h;

5-hydroxy-2-methyl-1,4-naphthoquinone (481-42-5) + chloromethyl methyl ether (107-30-2) → 5-methoxymethoxy-2-methyl-1,4-naphthoquinone (106914-49-2)

Conditions	Yield
Stage #1: 5-hydroxy-2-methyl-1,4-naphthoquinone With sodium hydride In N,N-dimethyl-formamide; paraffin oil at 0℃; for 0.0833333h; Stage #2: chloromethyl methyl ether In 1,2-dimethoxyethane; paraffin oil at 0℃; for 1.5h;	94%
With potassium carbonate In acetone

1-bromo-4-(2-vinylbuta-1,3-dienyl)benzene (906351-28-8) + 5-hydroxy-2-methyl-1,4-naphthoquinone (481-42-5) → (4aRS,9aSR)-1-(4-bromophenyl)-5-hydroxy-9a-methyl-2-vinyl-1,4,4a,9a-tetrahydroanthracene-9,10-dione

Conditions	Yield
With boron trifluoride diethyl etherate In dichloromethane at -35℃; Diels-Alder Cycloaddition; Inert atmosphere;	92%
With boron trifluoride diethyl etherate In dichloromethane at -30℃; Diels-Alder reaction;

5-hydroxy-2-methyl-1,4-naphthoquinone (481-42-5) + propionic acid (802294-64-0) → 5-O-propionoyl-2-methyl-1,4-naphthoquinone (1238220-30-8)

Conditions	Yield
With dmap; 2-methyl-6-nitrobenzoic anhydride; triethylamine In dichloromethane at 20℃; for 2h;	89%

5-hydroxy-2-methyl-1,4-naphthoquinone (481-42-5) + N-sulfinyl-4-methylaniline (15795-42-3) → 5-hydroxy-2-methyl-4-(4-methylphenyl)imino-1,4-dihydronaphthalen-1-one

Conditions	Yield
In benzene for 72h; Ambient temperature;	87%

5-hydroxy-2-methyl-1,4-naphthoquinone (481-42-5) + 2,2,2-Trichloroethyl chloroformate (17341-93-4) → O-trichloroethoxycarbonyl-plumbagone

Conditions	Yield
Stage #1: 5-hydroxy-2-methyl-1,4-naphthoquinone With pyridine In dichloromethane at 0℃; Inert atmosphere; Stage #2: 2,2,2-Trichloroethyl chloroformate In dichloromethane	87%

5-hydroxy-2-methyl-1,4-naphthoquinone (481-42-5) + ethyl iodide (75-03-6) → plumbagin ethyl ether

Conditions	Yield
Stage #1: 5-hydroxy-2-methyl-1,4-naphthoquinone With potassium carbonate In acetone at 20℃; for 0.0833333h; Stage #2: ethyl iodide In acetone at 80℃; for 1h;	87%

lauric acid (143-07-7) + 5-hydroxy-2-methyl-1,4-naphthoquinone (481-42-5) → 5-dodecanoyloxy-2-methyl-1,4-naphthoquinone

Conditions	Yield
With dmap; 2-methyl-6-nitrobenzoic anhydride; triethylamine In dichloromethane at 20℃;	86%

5-hydroxy-2-methyl-1,4-naphthoquinone (481-42-5) → 5-hydroxy-6-iodo-2-methyl-1,4-naphthoquinone

Conditions	Yield
With N-iodo-succinimide; dichloro(pentamethylcyclopentadienyl)rhodium (III) dimer; copper diacetate; silver(I) triflimide In dichloromethane at 45℃; for 2h; Inert atmosphere; Sealed tube; Microwave irradiation;	85%

copper(II) nitrate trihydrate + 5-hydroxy-2-methyl-1,4-naphthoquinone (481-42-5) + 4'-phenyl-2,2':6',2-terpyridine (58345-97-4) → [Cu(4'‐phenyl‐2,2':6',2''‐terpyridine)(plum)]NO3

Conditions	Yield
Stage #1: copper(II) nitrate trihydrate; 4'-phenyl-2,2':6',2-terpyridine In methanol; chloroform at 20℃; for 1h; Stage #2: 5-hydroxy-2-methyl-1,4-naphthoquinone With triethylamine In methanol; chloroform for 0.5h; Cooling with ice;	84%

1,10-Phenanthroline (66-71-7) + 5-hydroxy-2-methyl-1,4-naphthoquinone (481-42-5) + copper(I) bromide (7787-70-4) → C23H15BrCuN2O3*CH4O

Conditions	Yield
With sodium methylate In methanol at 20℃; for 2.5h; Reflux;	81%

5-hydroxy-2-methyl-1,4-naphthoquinone (481-42-5) + 2-bromoethyl phenyl selenide (50630-23-4) → C19H16O3Se

Conditions	Yield
With silver nitrate In acetonitrile at 20℃; for 1h;	81%

5-hydroxy-2-methyl-1,4-naphthoquinone (481-42-5) + (5Z,8Z,11Z,14Z,17Z)-eicosa-5,8,11,14,17-pentaenoyl chloride (98770-65-1) → 5-eicosapentaenoyloxy-2-methyl-1,4-naphthoquinone

Conditions	Yield
With pyridine; dmap at 20℃; for 4h; Inert atmosphere;	80%

5-hydroxy-2-methyl-1,4-naphthoquinone (481-42-5) + 4-chloro-3-trifluoromethyl-aniline (320-51-4) → 3-(4-chloro-3-trifluoromethyl-phenylamino)-5-hydroxy-2-methyl-[1,4]naphthoquinone

Conditions	Yield
With trifluoroacetic acid In methanol for 6h; Reflux;	80%

5-hydroxy-2-methyl-1,4-naphthoquinone (481-42-5) + 3-chloro-4-trifluoromethoxy-aniline (64628-73-5) → 3-(3-chloro-4-trifluoromethoxy-phenylamino)-5-hydroxy-2-methyl-[1,4]naphthoquinone

Conditions	Yield
With trifluoroacetic acid In methanol for 6h; Reflux;	80%

5-hydroxy-2-methyl-1,4-naphthoquinone (481-42-5) + dimethyltin(IV) diisopropoxide (26900-62-9) → (CH3)2Sn(C10H4O2(O)CH3)2

Conditions	Yield
In benzene byproducts: isopropanol; addn. of ligand to tin compd. soln. (ratio 2/1); refluxing; azeotropically fractionating, 3-5h; evapn.; crystn. (benzene or benzene/hexane 1/1); elem. anal.;	79%

bis(isopropoxy)diphenyltin(IV) + 5-hydroxy-2-methyl-1,4-naphthoquinone (481-42-5) → (C6H5)2Sn(C10H4O2(O)CH3)2

Conditions	Yield
In benzene byproducts: isopropanol; addn. of ligand to tin compd. soln. (ratio 2/1); refluxing; azeotropically fractionating, 3-5h; evapn.; crystn. (benzene or benzene/hexane 1/1); elem. anal.;	79%

1,10-Phenanthroline (66-71-7) + copper(II) nitrate trihydrate + 5-hydroxy-2-methyl-1,4-naphthoquinone (481-42-5) → C23H15CuN2O3(1+)*NO3(1-)*0.25H2O

Conditions	Yield
With sodium methylate In methanol at 20℃; for 2.5h; Reflux;	79%

Upstream product

• 64-17-5 ethanol 
• 58-27-5 menadione 
• 64-19-7 acetic acid 
• 116752-29-5 6-methyl-5,8-dioxo-5,8-dihydronaphthalen-1-yl acetate 
• 481-39-0 5-hydroxynaphtho-1,4-quinone 
• 116415-35-1 2-methyl-5-amino-1,4-naphthoquinone 
• 7732-18-5 water 
• 496-64-0 3-hydroxy-2-pyrone 
• 553-97-9 2-Methyl-1,4-benzoquinone 
• 126582-70-5 hydroplumbagin 4-O-β-D-glucopyranoside 
• 94410-15-8 plumbazeylanone 
• 39626-94-3 (3R,4R)-4,8-dihydroxy-3-methyl-3,4-dihydro-1(2H)-naphthalenone 
• 22266-99-5 2-methyl-5-methoxy-1,4-naphthoquinone 
• 69008-03-3 2-bromo-5-hydroxy-[1,4]naphthoquinone 

Downstream Products

• 91-57-6 2-Methylnaphthalene 
• 1374305-48-2 (11E)-N'-(5-hydroxy-2-methyl-1-oxonaphthalen-4(1H)-ylidene)benzohydrazide 
• 1374305-47-1 (11E)-2-hydroxy-N'-(5-hydroxy-2-methyl-1-oxonaphthalen-4(1H)-ylidene)benzohydrazide 
• 1446306-98-4 5-hydroxy-3-((4-methoxyphenyl)amino)-2-methylnaphthalene-1,4-dione 
• 1446306-99-5 5-hydroxy-3-((3-methoxyphenyl)amino)-2-methylnaphthalene-1,4-dione 
• 21890-57-3 5-hydroxy-2-methyl-3-chloro-1,4-naphthoquinone 
• 57093-07-9 3,6-dichloro-5-hydroxy-2-methyl-[1,4]naphthoquinone 

Relevant articles and documents

EPI-ISOSHINANOLONE FROM PLUMBAGO SCANDENS

Epi-isoshinanolone, a diastereomer of isoshinanolone, has been isolated from Plumbago scandens and characterized with the aid of NMR spectroscopy.Key Word Index - Plumbago scandens; Plumbaginaceae; epi-isoshinanolone; plumbagin; 13C NMR.

QUINONOID AND OTHER CONSTITUENTS OF ARISTEA ECKLONII

Aristea ecklonii; Iridaceae; quinones; plumbagin; biplumbagin; neoisoshinanolone; sterols.Plumbagin, 3,3'-biplumbagin, 8,8'-biplumbagin, neoisoshinanolone and sitosterol were isolated from the leaves and rhizomes of Aristea ecklonii.The rhizomes also contained α-spinasterol.This is the first report of plumbagin, previously found in several dicotyledonous families, in a monocotyledon.

ISOLATION AND STRUCTURES OF DIOMUSCINONE AND DIOMUSCIPULONE FROM DIONAEA MUSCIPULA

From the fresh leaves and roots of Dionaea muscipula, two new substances (diomuscinone and diomuscipulone) have been isolated together with the known naphthoquinone plumbagin.The structures of the new compounds have been elucidated on the basis of their spectral data coupled with some chemical evidence. - Key Word Index: Dionaea muscipula; Droseraceae; phenolic compounds; diomuscinone; diomuscipulone.

1,4-Naphthoquinones, XXIV: On the dehalogenation of 2-/3-halogen-1,4-naphthoquinone derivatives

Bu3SnH is an effective reagent for the debromination of 2-bromonaphthoquinones but elimination of chlorine with 1c, e.g., only proceeds at 30%. With Et3SiH dechlorination does not occur at all. Instead, with the 5-acetoxy derivatives 1a/1d as starting materials the cyclic acetales 3a-c are formed as selectively protected juglone derivatives. The bromo derivative 3a is obtained only at temp. 10° and even at room temp. Br-Elimination occurs with low yield of 3b. An especially suitable reagent for the debromination of 1a-b leading to the natural compounds plumbagin (2a) and isoplumbagin (2b) is zinc-silver couple but Cl-elimination again occurs in traces only.

Enantioselective Nickel-Catalyzed Reductive Aryl/Alkenyl-Cyano Cyclization Coupling to All-Carbon Quaternary Stereocenters

An enantioselective nickel-catalyzed intramolecular reductive cross-coupling of C(sp2) electrophiles and cyano groups is reported. Enantioenriched CN-containing all-carbon quaternary stereocenters are assembled by desymmetrizing cyclization of aryl/alkeny

Ruthenium-catalyzed C-H oxygenation of quinones by weak O-coordination for potent trypanocidal agents

Ruthenium-catalysis enabled the C-5 selective C-H oxygenation of naphthoquinones, and also sets the stage for the site-selective introduction of a hydroxyl group into anthraquinones. A-ring modified naphthoquinoidal compounds represent an important class of bioactive quinones for which the present study encompasses the first C-H oxygenation strategy by weak O-coordination.

A rapid, solvent-free deprotection of methoxymethyl (MOM) ethers by pTSA; An eco-friendly approach

Background: Ease of preparation and alkaline stability of methoxymethyl (MOM) makes it an important hydroxyl protecting group. A number of methods are available for the deprotection of MOM. Though the methods are good in general, they use solvents, require prolonged reaction time and tedious work up. A solvent free, solid phase, fast deprotection of MOM has been developed and is the major theme of this paper. Methods: A mixture of MOM protected compounds and pTSA is triturated in a mortar (5 min) and left at room temperature for 30 min. On addition of water (4°C), pTSA, methanol and formaldehyde dissolved leaving the products as precipitates. Results: A series of different MOM ethers were deprotected by this method in good to excellent yield (85-98%). The compatibility of MOM in the presence of other protections such as methoxyl, benzyl, ester, amide, allyl and lactone was also established. Acetate protection is not stable under these conditions. Conclusion: An efficient, selective and high yielding deprotection MOM groups by pTSA under solvent free condition is described. The process is environment friendly since no solvent was used in the deprotection process. The reaction conditions are mild and should be useful for the deprotection of MOM derivatives of complex and labile molecules.