3100-04-7

Basic information

• Product Name: 1-Methylcyclopropene
• Synonyms: Cyclopropene, 1-methyl-;1-Methylcyclopropene;Epa pesticide chemical code 224459;Ethylbloc;Hsdb 7517;Smartfresh;1-Methylcyclopropen;1-Methylcyclopropene in cyclodextrin
• CAS NO: 3100-04-7
• Molecular Formula: C₄H₆
• Molecular Weight: 54.09
• Product Categories: Agrochemicals
• Mol File: 3100-04-7.mol
• Article Data: 20

Chemical Properties

• Melting Point: 75-76 °C
• Boiling Point: 6.8oC at 760 mmHg
• Appearance: /
• Density: 0.838 g/cm³
• Vapor Pressure: 1440mmHg at 25°C
• Refractive Index: 1.474
• CAS DataBase Reference: 1-Methylcyclopropene(CAS DataBase Reference)
• NIST Chemistry Reference: 1-Methylcyclopropene(3100-04-7)
• EPA Substance Registry System: 1-Methylcyclopropene(3100-04-7)

Safety Data

• Hazardous Substances Data: 3100-04-7(Hazardous Substances Data)

Usage

Chemical Properties

1-Methylcyclopropene (1-MCP) is a derivative of cyclopropene, a small cyclic olefin with active chemical properties. 1-MCP is a synthetic plant growth regulator and is now widely used in commercial applications.

Uses

1-Methylcyclopropene (1-MCP) is a plant growth and ripening regulator. It acts as an inhibitor of ethylene by blocking the receptor of ethylene in the tissues of plants, flowers, fruit and vegetables, thus preventing the ripening process. It is used to inhibit ethylene production in cut flowers, potted flowers, bedding, nursery and foliage plants, and in stored fruits and vegetables. It is approved for use only in enclosed spaces, such as greenhouses, store rooms, coolers, enclosed truck trailers, controlled atmosphere food storage facilities, and shipping containers.

Definition

ChEBI: 1-methylcyclopropene is a member of the class of cyclopropenes that is cyclopropene in which the hydrogen at position 1 has been replaced by a methyl group. A gas at room temperture and pressure, it is a (synthetic) ethylene perception inhibitor and is used to prolong the life of cut and potted flowers, other ornamental plants, and fruit. It has a role as a plant growth regulator and an agrochemical. It is a member of cyclopropenes and a cycloalkene.

Health effects

Based on studies with laboratory animals, no adverse effects are expected to humans who are exposed to end products that contain 1-MCP, although eye irritation may occur if a user does not follow label directions. 1-MCP as a gas is not toxic to test animals. Human exposure is expected to be minimal because 1-MCP is approved only for use indoors, and the product label instructs people to leave the treatment space during treatment.

Regulations

Methylcylcolpropene (1-MCP) was registered as an active ingredient in April 1999. As of March 22, 2006, there are five registered products that contain this active ingredient. The EPA established an exemption from the requirement of a tolerance for residues of 1-MCP in or on fruits and vegetables when used as a post harvest plant growth regulator, i.e., for the purpose of inhibiting the ripening promotion effects of ethylene. This tolerance exemption became effective July 26, 2002 (67 FR 48796). At that time, EPA registered a new product allowing for post-harvest application to apples, apricots, avocados, kiwifruit, mangos, melons, nectarines, pears, papayas, peaches, persimmons, plums, and tomatoes.

InChI:InChI=1/C4H6/c1-4-2-3-4/h2H,3H2,1H3

Synthetic route

3-Chloro-2-methylpropene (563-47-3) → Methylcyclopropen (3100-04-7)

Conditions	Yield
With sodium hydride In toluene at 20 - 30℃; for 2h; Reagent/catalyst; Temperature; Solvent; Inert atmosphere;	92.6%
With lithium diisopropyl amide In mineral oil at 23℃; for 1.5h; Reagent/catalyst; Temperature; Time; Inert atmosphere;	60%
With lithium diisopropyl amide In mineral oil at 23℃; for 1.5h; Inert atmosphere;	60%

3-Chloro-2-methylpropene (563-47-3) → Methylcyclopropen (3100-04-7) + methylene cyclopropane (6142-73-0)

Conditions	Yield
With sodium amide	A 40% B n/a
With sodium hexamethyldisilazane In tetrahydrofuran at 65℃; Product distribution; Further Variations:; Reagents; Solvents; Temperatures;
With potassium hexamethylsilazane In toluene at -78 - 110℃; for 0.25h; Sealed tube; Reflux; Inert atmosphere;
With sodium amide; sodium t-butanolate In tetrahydrofuran at 65℃; for 9h; Schlenk technique; Inert atmosphere;

1,3-dibromo-2-methylpropene (35911-17-2) → Methylcyclopropen (3100-04-7)

Conditions	Yield
With ethanol; zinc at 70℃;

1,1,3,3-tetrachlorobutane (39185-82-5) → methylcyclopropane (594-11-6) + Methylcyclopropen (3100-04-7)

Conditions	Yield
With zinc In N,N-dimethyl-formamide at 25 - 30℃; Title compound not separated from byproducts;	A 8 % Chromat. B 56 % Chromat.
With zinc In N,N-dimethyl-formamide at 25 - 30℃; Product distribution; dechlorination of polychloroalkanes containing -CCl2CH2CCl2- group;	A 8 % Chromat. B 56 % Chromat.

1,1,1,3,3-pentachlorobutane (21981-33-9) → methylcyclopropane (594-11-6) + Methylcyclopropen (3100-04-7)

Conditions	Yield
With zinc In N,N-dimethyl-formamide at 25 - 30℃; Title compound not separated from byproducts;	A 4 % Chromat. B 29 % Chromat.

methylene (2465-56-7) + prop-1-yne (74-99-7) → but-1-yne (107-00-6) + dimethylacetylene (503-17-3) + Methylcyclopropen (3100-04-7)

Conditions	Yield
Rate constant;

Methacryloyl chloride (920-46-7) → Methylcyclopropen (3100-04-7)

Conditions	Yield
With sodium amide In ammonia at -78℃;

3-Chloro-2-methylpropene (563-47-3) → dimethylacetylene (503-17-3) + buta-1,3-diene (106-99-0) + Methylcyclopropen (3100-04-7) + methylene cyclopropane (6142-73-0)

Conditions	Yield
With sodium amide In tetrahydrofuran Yield given. Yields of byproduct given. Title compound not separated from byproducts;

1,2-diiodo-1-methylcyclopropane (653605-61-9) → Methylcyclopropen (3100-04-7)

Conditions	Yield
With ethylene dibromide; zinc In tetrahydrofuran for 20h; Reactivity;
With polymeric reagent In methanol at 20℃; Reactivity;
With potassium tert-butylate; para-thiocresol In DMF (N,N-dimethyl-formamide) at 20℃; for 0.25h; Reactivity;

1-methyl-1-(methanesulfonyloxy)-2-(trimethylsilyl)cyclopropane (936923-97-6) → trimethylsilyl fluoride (420-56-4) + Hexamethyldisiloxane (107-46-0) + Methylcyclopropen (3100-04-7)

Conditions	Yield
With tetrabutyl ammonium fluoride In dimethyl sulfoxide at -78 - 25℃; Reactivity; Inert atmosphere;

1-methyl-1-(methanesulfonyloxy)-2-(dimethylbutylsilyl)cyclopropane → Methylcyclopropen (3100-04-7)

Conditions	Yield
With tetrabutyl ammonium fluoride In dimethyl sulfoxide at -78 - 25℃; Product distribution / selectivity; Inert atmosphere;

trans-1-methyl-1-(methanesulfonyloxy)-2-(dimethylphenylsilyl)cyclopropane → Methylcyclopropen (3100-04-7)

Conditions	Yield
With tetrabutyl ammonium fluoride In dimethyl sulfoxide at -78 - 25℃; Product distribution / selectivity; Inert atmosphere;

1,1,2-tribromo-2-methyl-cyclopropane (130894-83-6) → Methylcyclopropen (3100-04-7)

Conditions	Yield
Stage #1: 1,1,2-tribromo-2-methyl-cyclopropane With n-butyllithium In decane at 20℃; Stage #2: With water In decane

1-methyl-1-(methanesulfonyloxy)-2-(trimethylsilyl)cyclopropane (936923-97-6) → Methylcyclopropen (3100-04-7)

Conditions	Yield
With tetrabutyl ammonium fluoride In diethylene glycol dimethyl ether at 20℃;

trans-1-methyl-1-(methanesulfonyloxy)-2-(butyldimethylsilyl)cyclopropane → Methylcyclopropen (3100-04-7)

Conditions	Yield
With 40% TBAF-DMF; sodium hydroxide at 30℃; for 0.5h; Reagent/catalyst; Temperature; Time;
With tetrabutyl ammonium fluoride In dimethyl sulfoxide at 40℃; for 2h;	92.2 %Chromat.

methylcyclopropenyllithium (130236-79-2) → Methylcyclopropen (3100-04-7)

Conditions	Yield
In diethyl ether at 0℃; Inert atmosphere;

phenylmagnesium bromide + Methylcyclopropen (3100-04-7) → (1-methylcyclopropyl)benzene (2214-14-4)

Conditions	Yield
In diethyl ether at 34℃; for 5h;	95%

Methylcyclopropen (3100-04-7) → dimethylacetylene (503-17-3) + 2,3-dimethylbutene (590-19-2) + buta-1,3-diene (106-99-0)

Conditions	Yield
With sulfur(VI) hexafluoride at 230.2℃; under 20.5 Torr; for 1.5h; Product distribution; Rate constant; Kinetics; var. time, var. pressure;	A 91.31% B 1.84% C 6.85%
Product distribution; Quantum yield; Irradiation;
In gas under 0.1 - 6 Torr; Mechanism; Product distribution; Irradiation;

Dithiooxalsaeure-O,O'-dimethylester (54129-78-1) + Methylcyclopropen (3100-04-7) → 3,4-Dimethoxy-1-methyl-2,5-dithiabicyclo<4.1.0>hept-3-en (76619-14-2)

Conditions	Yield
In tetrachloromethane	90%

cyclopenta-1,3-diene (542-92-7) + Methylcyclopropen (3100-04-7) → 2-methyl-endo-tricyclo<3.2.1.02,4>oct-6-ene

Conditions	Yield
	90%

Methylcyclopropen (3100-04-7) → (E)-2-methyl-3-bromo-2-propenyl acetate (105842-98-6)

Conditions	Yield
With N-Bromosuccinimide Ambient temperature;	86%
With N-Bromosuccinimide In acetic acid at 18℃;	70%

6,7,8,9-Tetrahydro-5H-cyclohepta-1,2,4-triazin-3-carbonsaeure-methylester (88396-07-0) + Methylcyclopropen (3100-04-7) → 3-Methyl-4,6,7,8,9,10-hexahydrocycloheptaazepin-2-carbonsaeure-methylester (88382-15-4)

Conditions	Yield
In chloroform for 6h;	84%

Methylcyclopropen (3100-04-7) → (E)-2-methyl-3-chloro-2-propenyl acetate (91989-11-6)

Conditions	Yield
With tert-butylhypochlorite Ambient temperature;	84%

1,2,4,5-tetrazine-3,6-dicarboxylic acid dimethyl ester (2166-14-5) + Methylcyclopropen (3100-04-7) → dimethyl exo,exo-2,6-dimethyl-9,10-diazatetracyclo[3.3.2.02.4.06.8]dec-9-ene-1,5-dicarboxylate

Conditions	Yield
In dichloromethane at 20℃;	75%

2,4-dinitrobenzenesulfenyl chloride (528-76-7) + Methylcyclopropen (3100-04-7) → 2-methyl-3-chloro-1-(2,4-dinitrophenylthio)-1-propene (76281-09-9) + 1-methyl-1-chloro-2-(2,4-dinitrophenylthio)cyclopropane (81651-95-8)

Conditions	Yield
lithium perchlorate In acetic acid	A 11% B 74%
In acetic acid for 1.5h; Ambient temperature;

7-Oxo-7H-cyclohepta-1,2,4-triazin-3-carbonsaeure-methylester (88382-18-7) + Methylcyclopropen (3100-04-7) → 3a-Methyl-6-oxo-2a,3,3a,6-tetrahydrocycloheptacyclopropapyridin-2-carbonsaeure-methylester (88382-19-8)

Conditions	Yield
In chloroform	74%

3,6-di(2'-pyridyl)-1,2,4,5-tetrazine (1671-87-0) + Methylcyclopropen (3100-04-7) → 1-methyl-2,5-bis(2-pyridyl)-3,4-diazanorcaradiene

Conditions	Yield
In dichloromethane; toluene at -78 - 20℃;	63%

Methylcyclopropen (3100-04-7) + 2,5-bis(2-pyridyl)-3,4-diazanorcaradiene → exo,exo-2-methyl-1,5-bis(2-pyridyl)-9,10-diazatetracyclo[3.3.2.02.4.06.8]dec-9-ene

Conditions	Yield
In dichloromethane; toluene at -78℃; than 20 deg C, 4 h;	63%

2,5-dimethyl-3,4-diphenyl-thiophene-1,1-dioxide (93768-65-1) + Methylcyclopropen (3100-04-7) → 3,4-diphenyl-1,2,5-trimethyl-1,3,5-cycloheptatriene (93768-66-2)

Conditions	Yield
In dichloromethane for 4h; Ambient temperature;	53%

Methylcyclopropen (3100-04-7) + 7-methyl-2,5-bis(2-pyridyl)-3,4-diazanorcaradiene → exo,exo-3,6-dimethyl-1,5-bis(2-pyridyl)-9,10-diazatetracyclo[3.3.2.02.4.06.8]dec-9-ene

Conditions	Yield
In dichloromethane at -78 - 20℃;	48%

Methylcyclopropen (3100-04-7) + 1-methyl-2,5-bis(2-pyridyl)-3,4-diazanorcaradiene → exo,exo-2,6-dimethyl-1,5-bis(2-pyridyl)-9,10-diazatetracyclo[3.3.2.02.4.06.8]dec-9-ene

Conditions	Yield
In dichloromethane; toluene at -78 - 20℃;	43%

Methylcyclopropen (3100-04-7) + 5,6-Diphenyl-1,2,4-triazin-3-carbonsaeure-methylester (35883-53-5) → 3-methyl-6,7-diphenyl-4H-azepine-2-carboxylic acid methyl ester (25872-26-8) + 5-methyl-6,7-diphenyl-4H-azepine-2-carboxylic acid methyl ester (25872-28-0)

Conditions	Yield
at 20℃;	A 17% B 42%

bis(trifluoromethyl)thioketene (7445-60-5) + Methylcyclopropen (3100-04-7) → 1-Methyl-3-(3,3,3-trifluoro-2-trifluoromethyl-propenylsulfanyl)-cyclopropene (33830-64-7)

Conditions	Yield
In dichloromethane 0°C;	31%
In dichloromethane 0°C;	31%

6-Oxo-5-phenyl-6H-[1,3,4]oxadiazine-2-carboxylic acid methyl ester (98171-26-7) + Methylcyclopropen (3100-04-7) → 4,7-Dihydro-3-methyl-7-oxo-6-phenyloxepin-2-carbonsaeure-methylester (127280-55-1) + 4,7-Dihydro-5-methyl-7-oxo-6-phenyloxepin-2-carbonsaeure-methylester (127280-54-0)

Conditions	Yield
In tetrahydrofuran at 20℃; for 3h; Yield given. Title compound not separated from byproducts;	A n/a B 28%
In tetrahydrofuran at 20℃; for 3h; Yields of byproduct given;	A n/a B 28%
at 20℃; Yield given. Yields of byproduct given;

7-Oxo-7H-cyclohepta-1,2,4-triazin-3-carbonsaeure-methylester (88382-18-7) + Methylcyclopropen (3100-04-7) → 5-Methylen-8-oxo-1,4,5,8-tetrahydro-1-azaheptalen-2-carbonsaeure-methylester (88396-05-8)

Conditions	Yield
In chloroform for 12h;	28%

Upstream product

• 35911-17-2 1,3-dibromo-2-methylpropene 
• 563-47-3 3-Chloro-2-methylpropene 
• 39185-82-5 1,1,3,3-tetrachlorobutane 
• 21981-33-9 1,1,1,3,3-pentachlorobutane 
• 2465-56-7 methylene 
• 74-99-7 prop-1-yne 
• 920-46-7 Methacryloyl chloride 
• 653605-61-9 1,2-diiodo-1-methylcyclopropane 
• 936923-97-6 1-methyl-1-(methanesulfonyloxy)-2-(trimethylsilyl)cyclopropane 
• 130894-83-6 1,1,2-tribromo-2-methyl-cyclopropane 
• 130236-79-2 methylcyclopropenyllithium 

Downstream Products

• 932-58-1 l-methyl dl-2,2-dimethylcyclopropane-1-carboxylate 
• 4049-81-4 2-methyl-1,5-hexadiene 
• 76281-09-9 2-methyl-3-chloro-1-(2,4-dinitrophenylthio)-1-propene 
• 81651-95-8 1-methyl-1-chloro-2-(2,4-dinitrophenylthio)cyclopropane 
• 103538-82-5 Acetic acid 2-(2,4-dinitro-phenylsulfanyl)-1-methyl-cyclopropyl ester 
• 81651-96-9 2-methyl-3-(2,4-dinitrophenylthio)-2-propenyl acetate 
• 140456-06-0 (E)-2-methyl-3-chloro-1-(2,4-dinitrophenylthio)propene 
• 820-71-3 methallyl acetate 
• 563-47-3 3-Chloro-2-methylpropene 
• 178742-89-7 3-Ethynyl-1-methylbicyclo<4.1.0>hept-3-ene 
• 178742-88-6 4-Ethynyl-1-methylbicyclo<4.1.0>hept-3-ene 
• 75-28-5 Isobutane 
• 541-50-4 2-acetoacetic acid 
• 106-99-0 buta-1,3-diene 

Relevant articles and documents

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Kinetics of molecular encapsulation of 1-methylcyclopropene into α-cyclodextrin

1-Methylcyclopropene (1-MCP), an ethylene inhibiting regulator, is commercially available in the form of an inclusion complex with α-cyclodextrin (α-CD). In this study, molecular encapsulation of gaseous 1-MCP into aqueous α-CD was investigated in a closed, agitated vessel with a flat gas-liquid interface. Molecular encapsulation of gaseous 1-MCP by α-CD is a simultaneous two-step reaction which involves the aqueous dissolution of gaseous 1-MCP and the encapsulation of the dissolved molecules by α-CD. The kinetics and mechanism of molecular encapsulation were analyzed based on the depletion rate of 1-MCP in the headspace of the vessel. The encapsulation rates could be explained quantitatively by the gas absorption theory with a pseudo-first-order reaction between 1-MCP and α-CD. The negative value of the calculated apparent activation energy of encapsulation (-24.4 kJ/mol) implied the significant effect of exothermic aqueous dissolution of 1-MCP. An encapsulation temperature of 15°C was optimal; at this temperature, the highest 1-MCP yield and best inclusion ratio of inclusion complex were obtained. Changes in the X-ray diffraction pattern suggested that the crystal lattice structure of α-CD was altered upon inclusion of 1-MCP.

METHODS FOR GENERATING PURIFIED CYCLOPROPENES

The present invention relates to methods of preparing purified cyclopropylene (1-methylcyclopropylene) gas employing one or more non-reactive purification processes to purify substances including, without limitation, cyclopropene (1-methylcyclopropylene) gas and/or lithio-cyclopropene.

Stereo- and Regioselective 1,3-Dipolar Cycloaddition of the Stable Ninhydrin-Derived Azomethine Ylide to Cyclopropenes: Trapping of Unstable Cyclopropene Dipolarophiles

A stereo- and regioselective 1,3-dipolar cycloaddition of the stable ninhydrin-derived azomethine ylide [2-(3,4-dihydro-2H-pyrrolium-1-yl)-1-oxo-1H-inden-3-olate, DHPO] to differently substituted cyclopropenes has been established. As a result, an efficient synthetic protocol was developed for the preparation of biologically relevant spiro[cyclopropa[a]pyrrolizine-2,2′-indene] derivatives. DHPO has proved to be an effective trap for such highly reactive and unstable substrates as parent cyclopropene, 1-methylcyclopropene, 1-phenylcyclopropene, and 1-halo-2-phenylcyclopropenes. It has also been found that 3-nitro-1,2-diphenylcyclopropene undergoes a nucleophilic substitution reaction in alcohols and thiols to afford 3-alkoxy- and 3-arylthio-substituted 1,2-diphenylcyclopropenes, which can be captured as corresponding 1,3-dipolar cycloadducts in the presence of DHPO. These new approaches provide a straightforward strategy for the synthesis of functionally substituted cyclopropa[a]pyrrolizine derivatives. The factors governing regio- and stereoselectivity have been revealed by means of quantum mechanical calculations (M11 density functional theory), including previously unreported Nylide-Hcyclopropene second-orbital interactions. The outcome of this work contributes to the study of 1,3-dipolar cycloaddition, as well as enriches chemistry of cyclopropenes and methods for the construction of polycyclic compounds with cyclopropane fragments.

Preparation method of 1-methylcyclopropene

The invention discloses a preparation method of 1-methylcyclopropene. 3-chloro-2-methacrylonitrile generates a ring-closure reaction under the effect of a NaH strong base catalyst with methylbenzene as a solvent, 1-methylcyclopropene sodium salt is generated and precipitated from the solvent methylbenzene, surplus raw materials and byproducts are left in the solvent, the raw materials and the solvent can be recycled through simple distillation to be cyclically used indiscriminately, the sodium salt is decomposed with water, and high-purity 1-methylcyclopropene can be obtained.