Phenyl-2-nitropropene

From Wikipedia, the free encyclopedia
1-Phenyl-2-nitropropene[1][2][3][4][5]
Names
Preferred IUPAC name
(2-Nitroprop-1-en-1-yl)benzene
Other names
P2NP
1-Phenyl-2-nitropropene
β-methyl-β-nitropropene
trans-beta-Methyl-beta-Nitrostyrene
(2-Nitro-1-propenyl)benzene
Identifiers
  • 705-60-2 ☒N
3D model (JSmol)
ChemSpider
ECHA InfoCard 100.155.731 Edit this at Wikidata
Properties
C9H9NO2
Molar mass 163.17 g mol−1
Appearance solid
Melting point 64 to 66 °C (147 to 151 °F; 337 to 339 K)
Hazards
GHS pictograms GHS07: Harmful
GHS Signal word Warning
GHS hazard statements
 H302, H315, H319, H335
P261, P264, P280, P301+312, P312, P302+352, P304+340, P305+351+338, P330, P332+313, P337+313, P362+364
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
☒N  (what is checkY☒N ?)
Infobox references

1-Phenyl-2-nitropropene, or simply Phenyl-2-nitropropene, or P2NP, as it is commonly referred to, is a chemical compound from the aromatic group of compounds, with the formula C9H9NO2. It is a crystalline solid of light yellow color with a distinct smell.[6] Phenyl-2-nitropropene is used in the pharmaceutical industry to manufacture the drug Adderall, an amphetamine mixture used to treat ADHD and narcolepsy. P2NP and other similar nitrostyrenes are also employed in the clandestine manufacture of drugs of the amphetamine class, and are listed as drug precursors in many countries.[7][8][9]

Uses[]

In the pharmaceutical industry P2NP is used to produce a racemic Amphetamine mixture, branded under the trade names Adderall and Mydayis, amongst others. In this case, the double bond is hydrogenated and the nitro group is reduced,[10] thus 1-phenyl-2-nitropropene becomes 1-phenyl-2-aminopropan, which is another name for Amphetamine. Different reducing agents and solvents are used for this reaction, and various protocols exist. Often LAH, Aluminum amalgam or raney nickel are used as a reducing agent, and the reaction is carried in a solvent like Isopropyl alcohol or THF[11][7][8]

Reduction of P2NP to Amphetamine


The above diagram depicts P2NP reduction to amphetamine by using either LAH, Sodium amalgam, Raney Nickel or Palladium (Pd) catalyst, as a reducing agent. Platinum (Pt) in the form of Adams' catalyst can also be used.[7]

P2NP can also be reduced to Phenylacetone, which is a precursor in the synthesis of methamphetamine. In this preparation, phenyl-2-nitropropene is reduced to phenyl-2-nitropropane using sodium borohydride, followed by hydrolysis of the nitro group with hydrogen peroxide and potassium carbonate to produce phenylacetone (1-phenyl-2-propan-2-one).[12]

Synthesis[]

In the lab, phenyl-2-nitropropane is produced by the reaction of Benzaldehyde and Nitroethane in the presence of a basic catalyst like n-Butylamine. The reaction is a Nitroaldol reaction, and is a variant of a Knoevenagel condensation reaction, which is one of a broader class of reactions called Henry condensations or simply Henry reactions, named after the Belgian chemist Louis Henry and the German chemist Emil Knoevenagel respectively.

Synthesis of phenyl-2-nitropropene

In this type of reaction, the basic catalyst deprotonates nitroethane to form a resonance stabilized anion. This anion nucleophilically adds to the aldehyde forming a beta nitro alcohol, which is subsequently dehydrated to yield the nitroalkene. Water is produced as a byproduct, and must be actively removed from the reaction mixture. Often, primary amines like n-Butylamine, Methylamine, and Ethylamine are used as catalysts. In some protocols anhydrous Ammonium acetate is used as catalyst.[6]

Many other drugs of the amphetamine class are produced in a similar fashion, where instead of benzaldehyde a similar compound - like a substituted benzaldehyde is used to produce a different nitrostyrene, that is later reduced to the desired amine, and the reaction protocols vary. One such reaction is the knoevenagel condensation of Piperonal (or 3-4-Methylene-Dioxy-benzaldehyde), which yields 3-4-Methylene-Dioxy-1-Phenyl-2-Nitropropene (or MDP2NP), which is later reduced to 3-4-Methylene-Dioxy-Amphetamine (or MDA), which can be later methylated to 3-4-Methylene-Dioxy-MethAmphetamine (or MDMA).[9] Another uses 2,5-Dimethoxybenzaldehyde to yield 2,5-Dimethoxy-beta-nitrostyrene. Many of those Knoevenagel condensations are used by dr. Alexander Shulgin, to yield over 100 amphetamine derivatives, in his book PiHKAL.[13][6][14]

Safety and Storage[]

P2NP is labeled as Harmful by the Globally Harmonized System of Classification and Labelling of Chemicals(GHS), and is a known irritant, thus breathing fumes and direct skin and eye contact must be avoided. The median lethal dose for oral exposure in rats and mice is greater than 500 mg/kg and 1176 mg/kg, respectively. Based on available data, the classification criteria are not met to classify Phenyl-2-Nitropropene as a carcinogen, however, the toxicological properties of p2np have not been thoroughly investigated.[3][4][2]

P2NP should be stored at 2°C to 8°C, away from strong oxidizing agents. At higher temperatures P2NP is not very stable, and degrades with time.[4][6]

References[]

  1. ^ Alfa Aesar entry on 2-Nitro-1-phenylpropene , accessed on March 20, 2021
  2. ^ Jump up to: a b Material Safety Data Sheet trans-β-Methyl-β-nitrostyrene (PDF) from Sigma-Aldrich, accessed on March 20, 2021
  3. ^ Jump up to: a b Material Safety Data Sheet P2NP (PDF) from Cayman Chemical, accessed on March 20, 2021
  4. ^ Jump up to: a b c Material Safety Data Sheet 1-(Phenyl)2-nitropropene (PDF) from Biosynth Carbosynth, accessed on March 20, 2021
  5. ^ "Chemical Book" Website - entry on 1-Phenyl-2-nitropropene, accessed on March 21, 2021
  6. ^ Jump up to: a b c d Phenyl-2-nitropropene synthesis via Ammonium acetate catalysis, 2021
  7. ^ Jump up to: a b c Synthetic Reductions in Clandestine Amphetamine and Methamphetamine Laboratories - A Review
  8. ^ Jump up to: a b Urushibara Style Amphetamine
  9. ^ Jump up to: a b [https://www.erowid.org/archive/rhodium/chemistry/mdp2np.html 3,4-Methylenedioxyphenyl-2-Nitropropene From Piperonal, Nitroethane & NaOH]
  10. ^ Организация Объединённых Наций (2007). "Синтез амфетамина. Восстановительное аминирование (каталическое восстановление с использованием металла)". Рекомендуемые методы обнаружения и анализа амфетамина, метамфетамина и их замещённых по циклу аналогов в конфискованных материалах. Нью-Йорк. p. 12. ISBN 9789214480303.
  11. ^ Организация Объединённых Наций (2008). "Синтез 1-фенил-2-пропанона". Бюллетень по наркотическим средствам. p. 40. ISBN 978-92-1-448027-3.
  12. ^ Phenyl-2-Propanone from Phenyl-2-Nitropropene #8
  13. ^ Pihkal: A Chemical Love Story, Alexander Shulgin and Ann Shulgin, 1991
  14. ^ Erowid, phenyl-2-nitropropene
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