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Safrole FAQ

edited by Predator, HTMLized by MescalToad


[ Back to the Chemistry Archive ]

Contents

1) Source plants and percentages (where available)
2) Physical and chemical properties
3) Extraction and refinement procedures
4) Characterisation and derivatives
5) Commercial sources (if you think it's worth the risk)
6) Some references.
7) Additions to the FAQ

Aim : to render fascist governmental purchase restrictions irrelevant, by providing information concerning natural and unregulated sources.

Note: has been stripped down of stuff unrelated to safrole or isosafrole in the precursor documents.


1) Safrole is everywhere. Source plants.

This list is not meant to be exhaustive. Further data would be welcome.

safrole)
Plant
Plant part/extract, safrole
percentage
Acorus calamus
(origin and % unknown)
Angelica polymorpha
(oil, origin and % unknown)
Asari seiboldii
(origin and % unknown)
A. sieboldii var. seoulense
(origin and % unknown)
Asari forbesii
(origin and % unknown)
Asari inflatum
(origin and % unknown)
Asari magnificum var dinghugense
(origin and % unknown)
Asari caudigerum var cardiophyllum
(origin and % unknown)
Atherosperma moschatum
(bark oil, % unknown)
Cananga odorata (Ylang Ylang)
(isosafrole : origin and % unknown)
Cinnamomum burmannii
(China, leaf/twig oil, 97-99% safrole)
Cinnamomum camphora
(root bark oil, 50-80% safrole)
var Yu-Sho Hangchow (China)
(wood oil, 2.9% safrole)
var Yu-Sho Kiukiang (China)
(wood oil, 0.8% safrole)
var Yu-Sho Nanchang (China)
(wood oil, 1.7% safrole)
var Hon-Sho (Japan)
(wood oil, 18.1% safrole)
var Ho-Sho (China)
(wood oil, 0.2% safrole)
Ho-Sho (Formosa)
(wood oil, 7.8% safrole)
Cinnamomum iners
(Malaysia, wood oil, high % safrole)
Cinnamomum micranthum
(wood oil, 95% safrole)
Cinnamomum oliveri
(bark oil, % unknown)
Cinnamonum parthenoxylon
(wood oil, Nees variety, 80%
Cinnamomum paucifolium
(China, leaf oil, 68-90% safrole)
Cinnamomum petrophilum
(China, leaf oil, 97% safrole)
Cinnamomum rigidissum
(China, wood oil, high % safrole)
Cinnamomum verum ("Ceylon Cinnamon")
(origin and % unknown)
Curuma amada
(steam-dist rhizome oil, 9.3% safrole)
Crowea exalata & spp.
(parts unknown, see Open AGRICOLA) [added may 28 2012]
Doryphora aromatica
(bark oil, % unknown)
Doryphora sassafras
(leaf oil, % unknown)
Eremophila longifolia
(leaf oil, % unknown)
Hamamelis virginiana
(0.5% of essential oil)(Witch Hazel)
Illicium parviflorum Michx
(origin unknown, 90% safrole)
Illicium religiosum (illiciacea)
(leaf oil, % unknown)
Illicium verum
(Star Anise... DISPUTED)
Juniper virginiana
(leaf oil, 11% safrole, 6% isosafrole)
Magnolia salicifolia (magnoliaceae)
(origin and % unknown)
Myristica fragrans
(volatile seed oil, 0.2-0.6% safrole)
Nemuaron humboldtii
(bark oil, % unknown)
Ocimum basilicum (labiatae)
(leaf juice, trace, % unknown)
Ocotea cymbarum
(wood oil, 84-93% safrole)
Ocotea pretiosa
(S America and % unknown)
Piper auritum
(Central America: leaf oil, 70%
Piper callosum
(Brazil: leaf oil, 70% safrole)
Piper hispidinervium
(Brazil: leaf oil, 81-88% safrole)
Piper nigrum
(black pepper, trace, % unknown)
Sassafras albidum
(wood oil, 80-85% safrole)
Theobroma cacao
(origin and % unknown)
Umbellularia californica
(leaf oil, % unknown)(Calif Sassafras)
Zieria smithii
(steam-distilled leaf oil, % unknown)

Oil of massoira bark (?) reputedly yields about 14% safrole.

 


A major source: CAMPHOR LAUREL ROOT : Cinnamomum Camphora

C. camphora is a pest xenophyte tree species now at plague proportions in regions such as northern NSW. They exude chemicals via their roots, into the soil, which kills worms and other soil biota; via their leaves which kill aquatic organisms near leaf-drop regions, and their berries sterilise the birds which eat them. They can live for over 1200 years. The canonical work on camphor and safrole production from this tree was performed by Dr Teikichi Hiraizumi, President of Takasago Chem Industry Co, Tokyo, and can be found in the essential oils work by Guenther.

CAMPHOR OIL is obtained by steam distillation of the wood of the camphor tree Cinnamonum camphora Sieb. (Lauraceae) growing in China, Taiwan, Japan [and Australia, where it is classed as a noxious weed]. The main constituent of the crude oil is camphor (ca. 50%) which can be separated by cooling and centrifugation.

Fractionation of the mother liquor gives two oils:
1) White camphor oil is the first distillation fraction (ca 20% of the crude camphor oil). It is a colourless or nearly colourless liquid with a cineole-like odour.

2) Brown Oil of camphor is a fraction with a boiling point higher than that of camphor (ca. 20%) It is a pale yellow to brown liquid with the odour of sassafras oil.

Density 1.064-1.075; Optical rotation [ND20] 1.51 - 1.55 [alpha]d 0 to +3? Flash point 6C. Solubility 1 vol in 2 vols of 90% ethanol.

The oil contains more than 80% safrole and, like Brazilian sassafras oil, is therefore used as raw material for the production of piperonal via isosafrole. Camphor oils with a high safrole content can also be obtained by steam distillation of the wood of Cinnamonum parthenoxylon Nees.

Three Varieties of camphor oils are produced.

Formosan Camphor oils camphor-linalool and camphor-safrole types.
Japanese Camphor oils camphor-safrole types.
Chinese Camphor oils cineole-terpineol-camphor (Apopin Oil) type.

Camphor oil "true" is produced by the steam distillation of the wood, rootstumps and branches of the type of Cinnamonum Camphora known as Hon-Sho, which grows in Formosa and Japan. [Ed Note: Hon-Sho oil holds 18.1% safrole)

Along with the crude oil comes a solid, partly crystalline mass of crude camphor. The oil is separated from the crude camphor by filterpressing. This yields crude camphor oil. The crude oil is subsequently fractionally distilled under vacuum, and yeilds another 50% of crude camphor. The remaining 50% of
filterpressed crude camphor oil is now free of camphor. It contains light terpenes, cineole, safrole, terpineol, sesquiterpenes, and sesquiterpene alcohols. These are separated into various fractions known as:

White Camphor oil The light fraction, containing cineole and monoterpenes.
Brown Camphor oil The medium heavy fraction containing up to 80% of safrole and some terpineol.

[Extended Monograph]
Brown oil of camphor is the medium heavy fraction from vacuum distillation of the camphor-free oil (aka white oil, filterpressed and camphor-free). Brown camphor oil amounts to 6 or 7 percent of the total oil, or 20-22% of the decamphorised oil. Brown oil is produced almost entirely in Formosa and Japan, from the Hon-Sho type of cinnamomum camphora, the camphor tree.

This fraction is most interesting from the perfumer's point of view. Its main constituent is safrole, and the redistilled brown camphor can be used directly in soaps for its magnificent masking effect. The safrole can be isolated from the oil and used as a starting material for heliotropine, vanillin and other perfume materials. Terpineol is also separated during the safrole-isolation and serves as is or may be transformed into terpinyl esters.

An artificial sassafras oil, "Oil Camphor Sassafrassy" is also produced from the brown oil by rectification and adjustment of the content of safrole, terpenes, etc.

 


JUNIPER leaves - juniper virginiana

Table below: representative volatile leaf oil composition for junipers (J. virginia var virginiana (USA), eluted from a DB-5 gas chromatography column. Data expressed in % of total oil, the oil derived from steam distillation of the FOLIAGE. (so no digging-up of the roots is required).

This gave us a list of approximately 140 distinct molecules which came off the column, I left most of them off.

The significant numbers are marked in red

RT(s)
Compound
%
B.P. (deg C) from Merck, 12th edn.
319 alpha-pinene 1.4 bp20:52.5 bp760:155-156
379 sabinene 6.7 No Listing
408 myrcene 0.9 beta from: bp10:44
481 limonene 18.9 bp763:175-176
608 terpinolene 0.5 No Listing
632 linalool 4.4 (dl) 194-197
734 camphor 3.7 mp:179 bp204
789 borneol 0.8 mp:(d)208 (l):204 bp:(d) 212:(l) 210
820 4-terpineol 1.5 bp:206-219 (d, l, and dl)
1101 safrole 10.9 mp:~11 bp:232-234
1229 cis-isosafrole 6.7 mp:~8.2 bp760:253 bp100:179.5
1403 methyleugenol 2.9 No Listing
1700 delta-cadinene 0.8 bp9:124

RT = retention time on the DB-5 column.

I gather this tree is known as the Red Cedar, though I think there are probably several trees which come under this moniker so there is room for confusion. It is also supposed to be the source of Red Cedarwood Oil, though the safrole content of this is unknown. Cedarwood oil is used for immersion
lenses in high-magnification microscope work.

Note: the incompetants at AUROMA Australia will supply you with the leaf oil of the communis species when you ask for the virginiana type. Ellisons of Nowra sell the seeds to this plant, which have reliably germinated.

 


Sassafras

There are numerous members of the sassafras family.

A guide to the safrole content sassafras oil is its congealing point.
Accuracy is approximatey 2%

% Safrole
Congealing Point C
100
11.0
90
7.5
80
4.6
70
1.7
60
-1.3

(ex: Planta Medica. 61(6):574-575, 1995 Dec.ISSN 0032-0943)

Abstract: The root bark of Sassafras albidum (Nuttall) Nees Lauraceae) was extracted at room temperature with hexane and chloroform as solvents. The isolated essential oils were analyzed with GC and GC/MS. Thirty compounds were identified, nine of which have not been previously reported from this species. The major compounds were safrole (85%), camphor (3.25%), and methyleugenol (1.10%). Ten sesquiterpenes were also identified.


Australian Native Tree Species Bearing Safrole


From the file: NATIVSAF.DOC
Content: List of Australian native trees alleged to contain safrole. Descriptions are supplied to assist recognition.


Page: 52 Fig: N/A Ref:16
Species: Eremophila longifolia
Family: Myoporaceae
Synonyms: Stenochilus longifolius
Vernacular names: `Berrigan', `Emu bush', `Dogwood'.
Appearance: Tall erect shrub, up to 6m high, drooping branches. Finely hairy youngish shoots give it a grey appearance. Alternate leaves, 5-17cm long, narrow and tapered at both ends. Purplish 2.5cm long flowers are externally hairy the flower lobe is longer than broad, flowers occur in groups of up to three. Fruit is ovoid or globular, fleshy, dark coloured with a single hard four-celled stone. Flowers nearly all year round.
Habitat: Limestone soils, usually inland, continental Aust except extreme north.
Active con: Leaves contain an essential oil rich in safrole and methyleugenol.


Page: 72 Fig: N/A Ref:21
Species: Zieria Smithii
Family: Rutaceae
Synonyms: None
Vernacular names: Sandfly Zieria, Sandfly Bush, Lanoline Bush, `Stinkwood'
Appearance: A small to tallish shrub with opposite leaves. Each leaf consists of three nearly hairless leaflets which vary from narrow to broadly egg-shaped, and are tapered at both ends, 2.5-5cm long. When crushed they exhibit a strong odour. Small 4-petalled white flowers occur in loose clusters in the forks of leaves in Spring.
Habitat: Common in sandy forest or cleared areas along the east coast from Victoria to Northern Queensland.
Active Con: Foliage essential oil. Safrole, elemicin and methyleugenol may be present in major amounts in the steam-distilled oil.


Page: 80 Fig: N/A Ref: 16
Species: Atherosperma moschatum
Family: Atherospermae (Maybe Monimiaceae)
Synonyms: None
Vernacular names: Sassafras (Native, Black, Victorian, Southern)
Appearance: Small to medium tree, aromatic in all its parts. Young branches, flowers and the underside of the leaves are brownish or greyish hairy. Its opposite leaves are rigid and tapered at both ends, sometimes with toothed margins. Leaves are often arranged in one plane, length from 3-10cm. Solitary summer flowers in leaf forks.
Habitat: In rainforest and moist gullies of Tas, Vic and N.S.W. as far north as the Barrington Tops district.
Active Con: The bark oil probably contains safrole. Also numerous alkaloids.
Author notes: This species can be found with effort near the Upper Causeway at Royal National Park, and also on the scree slopes of Wombarra, north of Wollongong, around the remains of the coal mine workings and impending drainage works.
Distillation: The leaves yield no safrole when dried, chopped finely and steam distilled, and only a miniscule amount of ti-tree (Maleleuca tree) - like oil.


Page: 83 Fig: N/A Ref: 71

Species: Cinnamomum laubatii
Family: Lauraceae
Synonyms: Cinnamomum tamala
Vernacular names: Camphorwood, Pepperberry, Pepperwood, Brown Beech.
Appearance: A tree up to 35m high with a straight, somewhat buttressed trunk and a smooth light brown bark, sometimes scaly on large trees. Freshly cut bark has a pleasant aroma. Young shoots and branchlets may be finely hairy. Leaves mostly opposite, oblong and tapered at both ends. 7.5-15cm long, showing three prominent ribs. Bunches of white flowers occur in upper leaf forks.
Habitat: Coastal rainforests of northern Queensland.
Active con: The bark oil contains safrole, and some alkaloids.


Page: 85 Fig: N/A Ref: 13, 16

Species: Doryphora aromatica
Family: Atherospermataceae
Synonyms: Daphnandra aromatica
Vernacular names: Sassafras (Grey, Northern Grey, Net Sassafras, Cheedingnan (Barron river)).
Appearance: A tree up to 35m high exhibiting large pustules, up to 6mm across. Both the yellow wood and the bark are very aromatic. Young branchlets are sometimes 4-angled. Young shoots and flowers are hairy. Leaves are opposite, elliptical, tapered at both ends, 6-15cm long and have toothed margins. Flowers are borne in the upper leaf forks at the end of the branchlets. Fruits are club-shaped or tubular, 1.5-2.5cm long. they split lengthwise when mature and release several tufted seeds. Differs from Daphnandra micrantha by being more aromatic and having less-toothed leaves as well as a larger plume of hairs on the seed.
Habitat: In the rainforests of northern Queensland.
Active con: The bark oil contains a volatile oil rich in safrole, plus several alkaloids.


Page: 86 Fig: N/A Ref: 16
Species: Doryphora sassafras
Family: Atherospermataceae
Synonyms: none
Vernacular names: Sassafras (NSW, caalang (Illawarra), boobin (North NSW), tdjuendegong (Brisbane Water).
Appearance: A large tree 20-30m high, exceptionally 40m. Opposite leaves are dark green and glossy, with coarsely toothed edges showing prominent veins on the underside. They are eliptical, tapered at both ends, narrowed at the base and 4-10cm long. Young shoots are silky hairy. Its short-stalked, starlike flower (usually three together) are pure white and occur in leaf forks, forming a stark contrast to the dark shining foliage. Flowers in early spring.
Habitat: In the rainforests of the eastern districts of NSW and south Queensland. It occurs in the blue mountains west of Sydney and as far west as the Jenolan caves.
Active con: The leaves contains an essential oil rich in safrole, plus several alkaloids.


Page: 151 Fig: N/A Ref: 107, 108
Species: Cinnamomum oliveri
Family: Lauraceae
Synonyms: none
Vernacular names: Sassafras (Oliver's, camphorwood).
Appearance: A tall tree up to 45m high, with a brown, nodular bark, very fragrant when cut. Its opposite leaves are narrow and tapered at both ends, glossy above and much paler below, 20cm long and 3.5cm broad. Velvety, cream coloured flowers occur in bunches 15-20cm long in upper leaf forks or at then end of branchlets. Fruits are oval berries, 12mm long, containing a single seed, sometimes irregular in shape owing to numerous galls. Flowers in late spring to early summer. The similar Beilschmiedia obtusifolata has much broader leaves.
Habitat: In the rainforests of northern NSW and southern Queensland.
Active con: The bark contains an essential oil rich in safrole, plus several alkaloids along with camphor, methyleugenol, or eugenol depending on the species. It is not certain that the Australian authorities would go on an enviropogrom in order to destroy these plants. They have attempted to suppress marijuana with only limited success. It is unlikely therefore that they can successfully suppress sassafras trees. Incidentally, yes you can find large stands of sassafras trees near a town called Sassafras, NSW.


2) Safrole.

CAS numbers: Safrole [94-59-7]
Related CAS numbers: dihydrosafrole [94-58-6]
1'-hydroxysafrole [5208-87-7]
isosafrole [120-58-1]
Merck Index entry: 12th edition #8468
Beilstein entry: p 553 of _19_, 1 ,V.
Beilstein Database Registry Number: 136380.

Synonymi

1,2-methylenedioxy-4-allylbenzene 3,4-methylenedioxyallylbenzene 5-(2-propenyl)-1,3-benzodioxole 4-allyl-1,2-methylenedioxybenzene allylchatecol methylene ether allyldioxybenzene methylene ether
m-allylpyrocatechin methylene ether allylpyrocatecholmethylene ether 1-allyl-3,4-methylenedioxybenzene

Safrole is also informally known as shikimole, by some bizarre phonetic allusion to shikimic acid, a biological precursor to several aromatic compounds, but which is chemically quite distant to safrole. The Japanese name for Illicium religiosum Sieb et. Zucc is "Shikimi"

Some Physical Properties

Chemical class: aromatic bicyclic phenol ether
Solubility : insoluble in water very soluble in ethanol, chloroform, diethyl ether volatile with steam
Habit : Colourless or a reddish yellow liquid at room temp. Solidifies into monoclinic prisms

Molar abosorption co-efficients at peak absorbance frequencies
Peak Wavelength
Absorbance ( )
236nm
4168.6
285nm
3801.9

Molar Heat of vapourisation : 13.2255kCal/gram mole

Heat of combustion : 1244.1 cal/kg

Diamagnetic susceptibility:

Melting pt : 11.2 C (Crude isolates are reported to melt at 7-8C)

Boiling pts : 231.5 C at 760 mmHg (101.3kPa, atmospheric pressure)
233 C at 759 mmHg
100-101.5 C at 11 mmHg
91 C at 4 mmHg

Flash point : 97C
Optic Rotation: nD(20) 1.5383
Density : 1.096 g/cc at 20C
Mol Wt : 162.18g/mol
Empirical formula : C10H10O2
Structural formula : CH2:CHCH2C6H3O2CH2


Smell

Safrole's smell has been variously described in terms of other molecules. Safrole probably interacts with the same olfactory G-coupled receptors as the volatiles in the anise plant, and this makes sense insofar as some of the components in the oil of anise are structurally similar [but not the same as -- Erowid] to safrole. It is accurately described as a candy-shop odour. Go into a place which sells more sugary things than chocolatey things and take a deep whiff. It is also reminiscent of ginger. It has been described as smelling like MDMA, anise, rootbeer, sassafras oil, MDA, mCPP or sodium lactate. Halo-derivatives of
safrole are said to have similar smells to the parent molecule. Safrole is conspicuously absent from the Sigma-Aldrich Flavours and Fragrances catalog. Some useful derivatives of safrole (piperonal "sweet, floral", piperonyl acetate, "cherry, strawberry", piperonyl acetone and piperonyl isobutyrate "fruity, berry") are present, however.

Structural diagrams

Toxicity

LD50 in rats is 2.35g/kg. It is mainly metabolised by the cytochromes P450. Neither sassafras nor the oil should be taken internally. The use of herb teas of sassafras may lead to a large dose of safrole. The use of safrole in foods has been banned because of carcinogenic and hepatotoxic risks. The use of safrole in toilet preparations is also controlled. A 47 year old woman experienced 'shakiness', vomiting, anxiety, tachycardia and raised blood pressure following ingestion of a potentially fatal dose of sassafras oil (5mL). Treatment was symptomatic following the use of activated charcoal.
See: Grande GA, Dannewitz SR,
Symptomatic Sassafras Oil Ingestion,
Vet. Hum. Toxicol 1987 29 447
Recognized Carcinogen P65, Suspected Gastrointestinal or Liver Toxicant, Kidney Toxicant, Neurotoxicant, Reproductive Toxicant. More hazardous than most chemicals in 6 out of 7 ranking systems. At least 8 covalent adducts are formed when calf thymus DNA is incubated with safrole-2',3'-oxide,an oxygenated metabolite of safrole in vitro. However, no corresponding adducts are formed with liver DNA when whole animals are exposed to safrole 2',3'-oxide, or safrole itself. Although safrole 2',3'-oxide is readily formed in vivo, and is sufficiently reactive to covalently bind to DNA, it is probably not a factor in the in vivo genotoxicity of safrole. Tox. Letters. 75(1-3):201-207, 1995 Jan. ISSN 0378-4274

Safrole FTIR Spectrum

 

Applications

Safrole was used for decades in perfumes and medicines until in the 1960's. Its primary industrial application was conversion to isosafrole, a precursor to a dye called heliotropin and vanillin, a flavour molecule. In the 1990s it was listed, along with isosafrole, on the prohibited import regulations list, due to its application as a precursor in the synthesis of banned psychoactive methamphetamines. It is still used in the preparation of the following pharmaceutical products:
Humexinal, Inhalador Vicks, Linimento Klari, Linimento Walderr, Zam-Buk and Vegebom du Dr Miot, though in small quantities. Piperonyl butoxide, which is used as a synergist in aerosol pesticides, is probably synthesised from a safrole-derived feedstock.


3) Safrole extraction and refinement

Isolating Methods

Soxhletting the root bark of cinnamomum camphora (camphor laurel), or probably parts of other plants (see below) with distilled ethanol, or hexane and chloroform, yields most of the available safrole, and is cheap and effective. The solvents can be evaporated off or reclaimed by distillation.
Dealing with the impurities in the soxhlet extract is another matter. Steam distillation from bulk plant material is also reported to work.

Refinement methods from oil

  1. Cool the oil or the safrole-containing fraction of the oil, to at least -12C. Safrole will crystallise.
  2. Use fractional distillation, followed by cooling and crystallisation. Regarding the distillation of safrole in mixtures consult Brauer, Ber Schimmel & Co, Jubil?ms-Ausgabe (1929), 153.
  3. Where safrole may be contaminated by oily constituents in an essential oil as in red camphor oil, the method of Ikeda and Takeda (a) may be employed advantageously to determine the safrole by reparation of the addition product with mercuric acetate and sodium chloride in dilute acetone. The precipitate so formed should be filtered in a Gooch funnel and weighed, and used with a correction factor to define the percentage of safrole in the sample. This complex hydroxychloride of safrole [C10H10O2(OH)HgCl] according to Tsukamoto (b) is readily decomposed to regenerate safrole either by sodium sulfide and zinc in potassium hydroxide; or hydrochloric acid. The oxychloride melts at 141-142C according to Fujita (c).

a) See: J. Chem. Soc. Japan 57 (1936) 565
Chem Abstracts 30 (1936) 7497
Chem Abstracts 37 (1943) 3882
b) See: J. Pharm. Soc. Japan 50 (1930) 7
c) See: J. Chem. Soc. Japan 58 (1937) 1185
Chem Abstracts 32 (1938) 3904

 


4) Derivatives and characterisation

Safrole will convert to allylpyrocatechol when heated with phosphoric acid. Safrole is oxidised to piperonylic acid (mp 238C) by the action of potassium permanganate in aqueous acetone. Some piperonylacetic acid (mp 87-88C) is also produced. Safrole is oxidised to piperonal (heliotropin, mp 38C) by the action of potassium dichromate and dilute sulfuric acid. Safrole isomerises to isosafrole when heated with alkalis. See also step (3) in isolation, above.

Isosafrole (120-58-1)

Isosafrole is technically a member of the styrenes and polymerises under the influence of acids. It is soluble in ethanol, ether, benzene and is steam-volatile. It shares safrole's empirical formula and molecular weight. Isosafrole exists in two isomeric forms, the cis- isomer and the more energetically favourable trans-isomer. Warming converts the cis-form to the trans-configuration. Isosafrole is not as widely distributed in nature as safrole. It is best purified via a picrate derivative, the trans- isomer of which has mp 74.75C. The picrate cis- isomer melts at 68.5C.
Cis-isosafrole boils at 253C at 760mmHg; 179.5C at 100mmHg.
Trans-isosafrole melts at 6.7-6.8C and boils at 247-247C.
Trans-isosafrole has a density of 1.122g/cc.

Halo-adducts

Tribromosafrole dibromide,
("pentabromosafrole") is prepared by dissolving 0.41g of safrole in 3mL of ethanol, and treatment with 2g bromine for eight minutes. Heat for 15 minutes on a water bath, then cool. Recrystallise the solid from 7mL of benzene. Needles, m.p. 169-170C.

The 2-bromo-product,
the propyl arm is substituted with Br at the 2 position, from reaction with HBr, is in Beilstein on p228 of _19_, 3/4, I. This bromo material is reported to have a density between 1.5614 and 1.5640, with the following boiling points for given pressures in mmHg:

C10H11O2Br

mmHg
bp
13 154-157 C
9 145 C
5 130-135 C

References for this 2-bromopropyl product include (from Beilstein)
Orcutt, Bogert, Am. Soc. 58 [1936] 2055;
Liebermann et al, Am. Soc. 69 [1947] 1540;
Sakakibira, J. Chem. Soc Japan Pure Chem. Sect 73, [1952] 235;
C. A. 1953 10511.

Markownikov Br-product
Getting this Markownikov depends on the absence of peroxides in the precursor materials, such peroxides can be sequestered out by the addition of a small quantity of hydroquinone (used in photography) to the reaction. The 2-iodo-equivalent of the above, C10H11O2I is produced with HI under DMSO.

 


5) Non regulated commercial sources

Not tested: your mileage may vary.
Why would you want a tonne of safrole? Why, for synthesis into piperonyl butoxide for use in insecticidal preparations, or manufacture of dyes, flavours, etc, of course, and you're too lazy to extract it from plants. Oils to order include:
Juniper (var. virginialis) Oil, Sassafras Oil, Brown Oil of Camphor, Nutmeg Oil.

7 Old Bailey St
Central
Hong Kong

Urlekram A/S
Klostermarken 20, DK-9550 Mariager
Denmark

Terapi Consult AS
Frysjavien 27
0883 Oslo
Norway

Luonnonruo Katukku
Adukiky
Kirvesmeihenkatu 10, 00810 Helsinki
Finland

Whitefoods Wholesale
Unit 2D, Kylemore Industrial Estate
Dublin 10, Republic Of Ireland

Marunaka KK
1-12-4 Ginza Chuo-ku
Tokyo Japan

Grace & Pearl Corp'n
6, Lane 97
Tung An St
Taipei
Taiwan

Orient Resources Company, 506 Lucky Commercial Centre,
103-109 Des Voeux Road West, Hong Kong.
Tel: +852 25172316 Fax: +852 25178741

Product
Origin
Specs
Packing
Price/Kg
Nutmeg Oil Sri Lankan   100/200kg $16.90
Pepper Oil Sri Lankan   10/25/40kg $70.00
Sassafras Oil   95% safrole   $6.00

Prices quoted are for reference only in US$ on fob basis valid on 1st August, 1996. Please contact us for firm quotations. Shipments can be made by sea/air, minimum order US$5000. Quantity discounts available. E-mail Questions and comments to orient@orc.com.hk 1995-97

 


6) References

General:
Australian Medicinal Plants E.V. Lassak and T McCarthy 1983 Methuen Australia
44 Waterloo Rd North Ryde NSW 2213 ISBN: 0454004389 Dewey: 581.6'34'0994
Dictionary of Plant Toxins (Baxter) 1996 J.Wiley and sons. ISBN 0471951072
CRC Handbook of Medicinal Herbs (Duke) CRC Press
Volumes 1-6, "The essential oils / by Ernest Guenther" 1948-56
Modern Methods of Plant Analysis : Essential Oils and Waxes
Edited by H.F. Linskens and J. F. Jackson (1991) ISBN 0-387-51915-7 and
3-540-51915-7 Springer-Verlag p153 Dewey Call No. is 581.19072/1c/(12) ).

Australian native sources of safrole:
R. Hegnauer, Chemotaxonomie der Pflanzen, Vol 6, Birkhauser Verlag, Basel
(1969)
S.L.Everist, Poisonous Plants of Australia, Angus and Robinson, Sydney
(1974)
31: L.J.Webb, Australian Phytochemical Survey, Part 2, CSIRO Bulletin
#268;
Government Printer, Melbourne (1952)
71: T.G.H.Jones, F. Berry-Smith, Proceedings of the Royal Society of
Queensland, 37, 89 (1928)
107:J.Lauterer, Proceedings of the Royal Society of Queensland, 11, 20
(1894/5)
108:E.Gildemeister and F.Hoffmann, Die Aetherischen Oele, vol. 5
Akademie Verlag, Berlin, (1959)

Other sources of Safrole:
J G Maia et al, 'New Sources of Natural Safrole' in Perfumer & Flavorist
Vol 18, Issue 2 March/April, p 19-22 (1993)
L Zhu, D Ding, B Lawrence, 'The Cinnamomum Species in China: Resources
for
the Present and Future', Perfumer & Flavorist Vol 19, issue 4, p17 (1994)

Safrole chemistry
Merck Index entry: 12th edition #8468
PIHKAL, Alexander Shulgin, Transform Press
Beilstein entry: p 553 of _19_, 1 ,V.
Perkin W. H, J. Chem. Soc. 1927 (1663)
Martindales Pharmacopoea (30th Edn) entry p1410.3 (sassafras oil)
FTIR: Morrison & Boyd Organic Chem (3rd Edn) Page 814, Fig FFF: Safrole.


7) Addenum

(Addition by "Indole"):

Chenopodium ambrosioides var. anthelminticum (Wormseed) (flowering plant, % unknown)
(this one is an oil that is restricted in most countries, apparantly due to it's high ascaridole (up to 80%) content)
Note by MescalToad: ascaridole is an unstable (even explosive) peroxide.

These are additions to the species already mentioned:

Cananga odorata (add. var. macrophylla, other variety doesn't seem to have safrole/isosafrole), also Cananga odorata appears to have safrole, never seen info saying it had isosafrole...

Myristica fragrans (volatile seed oil, 0.2-0.6 (my ref has reports up to 2%)
Myristica fragrans add:(husk oil, >1%)

Also, you could probably change Illicium verum from (Star Anise... disputed) to (fruit, unknown) or (fruit, low%) as the same ref. I keep mentioning has info on this one...although it is low... DISPUTED

here's the ref if you need it:
Sheppard-Hanger, Sylla. (1995) "The Aromatherapy Practitioner Reference Manual" Atlantic Institute of Aromatherapy, Tampa (Florida)

 


Anonymous:

Just thought you might like to add some info onto your safrole FAQ sheet on your site. The Australian botanicals, southern sassafras and ziera smiithi have no safrole in their roots, bark, trunks or foliage. Southern sass has nothing worth mentioning whilst smiithi contains lots of methyl eugenol, which is where the confusion started I believe, the text 'poisionous plants of Australia' is fraught with errors and as much of the info in the current Safrole FAQ is lifted directly from this hence the errors. This will save readers much time I believe as I have wasted heaps of time collecting , seperating and steam distilling all the bits. The methyl eugenol's existence was confirmed through FTIR and NMR library matches so there is no doubt to the accuracy of this info. The only assumption I am making is that maybe safrole only seasonally appears in these species, as my samples were all collected in winter/spring.


Notes:

Illicium verum - Star Anise - Note : RA points out that research has shown star anise contains no or very low levels of safrole and high levels of anethole, a structurally similar oil. If synthetic techniques designed for safrole are used on anethole, dangerously different final chemicals can result, such as PMA instead of MDMA. (Added by Erowid July 2007)