57-14-7

Basic information

• Product Name: 1,1-Dimethylhydrazine
• Synonyms: 1,1-Dimethylhydrazine;Dimazin;Dimazine;Heptyl;N,N-Dimethylhydrazine;NSC 60517;UDMH;Unsymmetrical dimethylhydrazine;as-Dimethylhydrazine;gem-Dimethylhydrazine;u-Dimethylhydrazine;unsym-Dimethylhydrazine
• CAS NO: 57-14-7
• Molecular Formula: C₂H₈N₂
• Molecular Weight: 60.09832
• EINECS: 200-316-0
• Mol File: 57-14-7.mol
• Article Data: 28

Chemical Properties

• Melting Point: -57.2℃
• Boiling Point: 63.9 °C at 760 mmHg
• Flash Point: 1.1 °C
• Appearance: clear colorless liquid with an ammonia-like odor
• Density: 0.829 g/cm³
• Refractive Index: 1.4065-1.4085
• Water Solubility: miscible
• CAS DataBase Reference: 1,1-Dimethylhydrazine(CAS DataBase Reference)
• NIST Chemistry Reference: 1,1-Dimethylhydrazine(57-14-7)
• EPA Substance Registry System: 1,1-Dimethylhydrazine(57-14-7)

Safety Data

• Hazard Codes: F:Flammable;;
• Statements: R11:; R23/25:; R34:; R45:; R51/53:
• Safety Statements: S45:; S53:; S61:
• RIDADR: 1163
• HazardClass: 6.1
• PackingGroup: I
• Hazardous Substances Data: 57-14-7(Hazardous Substances Data)

Usage

General Description

1,1-Dimethylhydrazine, also known as unsymmetrical dimethylhydrazine (UDMH), is a highly volatile, flammable, and toxic liquid compound. It is primarily used as a rocket propellant and as a precursor to some pharmaceuticals and agricultural chemicals. Exposure to 1,1-Dimethylhydrazine can cause adverse health effects such as respiratory tract irritation, nausea, vomiting, and damage to the liver and kidneys. The substance is also classified as a probable human carcinogen, with long-term exposure linked to an increased risk of developing cancer. Due to its hazardous nature, strict safety precautions and handling procedures are necessary when working with 1,1-Dimethylhydrazine to minimize the risk of exposure and potential harm to human health and the environment.

InChI:InChI=1/C2H8N2/c1-4(2)3/h3H2,1-2H3

Synthetic route

(5S,5aS,8aS)-5-(N',N'-Dimethyl-hydrazino)-1,3,7-trimethyl-5,5a,8a,9-tetrahydro-1H-pyrrolo[3,4-g]quinazoline-2,4,6,8-tetraone (127510-73-0) → 1,3,7-Trimethyl-8a,9-dihydro-1H-pyrrolo[3,4-g]quinazoline-2,4,6,8-tetraone (127510-75-2) + 1,1-dimethylhydrazine (57-14-7)

Conditions	Yield
With hydrogenchloride In ethanol	A 92% B n/a

(η5-C5Me4SiMe3)2Ti(Cl)(NHN(CH3)2) → 1,1-dimethylhydrazine (57-14-7)

Conditions	Yield
With (η5-C5Me5)Rh(2-pyridylphenyl)H; hydrogen In tetrahydrofuran at 23℃; under 3040.2 Torr; for 120h; Catalytic behavior; Reagent/catalyst; Inert atmosphere; Schlenk technique;	87%

1-acetyl-2-methylhydrazine (29817-35-4) + platinum-on-carbon + isopropyl alcohol (67-63-0) → 1,1-dimethylhydrazine (57-14-7)

Conditions	Yield
With hydrogenchloride; formaldehyd; paraformaldehyde; platinum	78%

N-Nitrosodimethylamine (62-75-9) → 1,1-dimethylhydrazine (57-14-7)

Conditions	Yield
With titanium(III) chloride In water for 1h; Ambient temperature;	70%
With lithium aluminium tetrahydride; diethyl ether
With sodium hydroxide; aluminium

(η5-C5Me4SiMe3)2Ti(NHN(CH3)2) → 1,1-dimethylhydrazine (57-14-7)

Conditions	Yield
With cyclopentadienylchromiumtricarbonyl hydride; hydrogen In tetrahydrofuran at 23℃; under 3040.2 Torr; for 120h; Catalytic behavior; Reagent/catalyst; Inert atmosphere; Schlenk technique;	15%

tetrachloromethane (56-23-5) + N,N-dimethylcarbamoyl azide (13750-17-9) → 1,1-dimethylhydrazine (57-14-7)

dimethylchloroamine (1585-74-6) → 1,1-dimethylhydrazine (57-14-7)

Conditions	Yield
With ammonia
With ammonia; dimethyl amine at 35℃; under 9000.72 Torr; for 0.833333h; Product distribution; Further Variations:; educt/reagent ratios;
With sodium amide In kerosene
With tri-n-propylamine
With ammonium hydroxide at 25℃; pH=13; Kinetics;

N-nitrodimethylamine (4164-28-7) → 1,1-dimethylhydrazine (57-14-7)

Conditions	Yield
With acetic acid; zinc
With sulfuric acid durch elektrolytische Reduktion an einer verzinnten Kupferkathode;

N,N-dimethylcarbamoyl azide (13750-17-9) → 1,1-dimethylhydrazine (57-14-7)

Conditions	Yield
With xylene und Erhitzen des in Xylol unloeslichen Anteils des Reaktionsprodukts mit konz. Salzsaeure im Autoklaven auf 150grad;

N-ethyl-N,N-dimethyl-hydrazinium; hydroxide → ethene (74-85-1) + 1,1-dimethylhydrazine (57-14-7)

Conditions	Yield
at 170 - 250℃;

dimethyl amine (124-40-3) → 1,1-dimethylhydrazine (57-14-7)

Conditions	Yield
With sodium hydroxide; chloroamine In water at 25℃; Rate constant; Kinetics; variation of temperature, effect of pH and concentration of reagents;
With chloroamine

methyl iodide (74-88-4) → 1,1-dimethylhydrazine (57-14-7)

Conditions	Yield
With water; hydrazine hydrate

1-(2'-nitrophenyl)-3,3-dimethyltriazene (20241-01-4) → 1,1-dimethylhydrazine (57-14-7) + 1,2-diamino-benzene (95-54-5)

Conditions	Yield
With Britton-Robinson buffer In methanol Product distribution; Mechanism; pH dependence, polarographic reduction;

3-Amino-1,1-dimethyl-4,5-dihydro-1H-pyrazol-1-ium; iodide (60250-44-4) → 1,1-dimethylhydrazine (57-14-7)

Conditions	Yield
With sodium hydroxide for 3.5h; Heating; Yield given;

2,2-dimethyltriazanium nitrate → methane (34557-54-5) + Monomethylammonium nitrate (22113-87-7) + 1,1-dimethylhydrazine (57-14-7)

Conditions	Yield
at 89.9 - 110.8℃; Rate constant;

dimethyltriazanium chloride (13166-44-4) → methane (34557-54-5) + methylamine hydrochloride (593-51-1) + 1,1-dimethylhydrazine (57-14-7)

Conditions	Yield
at 94.3 - 112.8℃; Rate constant; also heat evolution rates at 112.8 deg C in aqueous solutions and 0.1 N NaOH solution;

dimethyl amine (124-40-3) → dimethylchloroamine (1585-74-6) + 1,1-dimethylhydrazine (57-14-7)

Conditions	Yield
With chloroamine at 18.9 - 31.9℃; Kinetics; Rate constant; pH 8 - pH 13; ΔH(excit), ΔS(excit), reactions under var. conditions;

dimethyl amine (124-40-3) → dimethylchloroamine (1585-74-6) + N-methyl-N-(methyleneamino)methanamine (2035-89-4) + 1,1-dimethyldiazene (35337-56-5) + 1,1-dimethylhydrazine (57-14-7)

Conditions	Yield
With chloroamine at 24.9℃; Mechanism; Rate constant; Kinetics; ΔH; ΔS; effect of pH;

dimethylchloroamine (1585-74-6) + urea (57-13-6) → tetramethylhydrazine (6415-12-9) + dimethyl amine (124-40-3) + 1,1-dimethylhydrazine (57-14-7)

Conditions	Yield
With potassium hydroxide In methanol; tert-butyl alcohol for 8.25h; Ambient temperature;	A 17.2 % Spectr. B 4.3 % Spectr. C 2.4 % Spectr.
With potassium hydroxide In methanol; tert-butyl alcohol for 8.25h; Product distribution; Mechanism; Ambient temperature;	A 17.2 % Spectr. B 4.3 % Spectr. C 2.4 % Spectr.

1-amino-1,4,4-trimethylpiperidinium mesitylenesulfonate (76093-78-2) + methyl iodide (74-88-4) → 3,3-dimethyl-penta-1,4-diene (1112-35-2) + 1,1-dimethylhydrazine (57-14-7)

Conditions	Yield
With potassium tert-butylate In tert-butyl alcohol for 24h; Product distribution; Heating;

N-Methylurea (598-50-5) → methanol (67-56-1) + formaldehyde monomethylhydrazone (36214-48-9) + 1,1-dimethylhydrazine (57-14-7) + methylhydrazine (60-34-4) + 1-methyltriazane + 2,3,4-triaza penta-1,3-diene

Conditions	Yield
With chloroamine In diethyl ether; water for 5h; Product distribution; Mechanism; other solvent, exposition;

1,2,5-trimethyl-2,3-dihydro-1H-pyrazol-3-one (3201-26-1) + alcoholic KOH-solution → 1,1-dimethylhydrazine (57-14-7)

Conditions	Yield
at 190℃; im Rohr;

trimethylhydrazonium hydroxide → 1,1-dimethylhydrazine (57-14-7)

Conditions	Yield
under 150 Torr; bei der trocknen Destillation;

N-nitrodimethylamine (4164-28-7) + sulfuric acid (7664-93-9) + copper cathode → 1,1-dimethylhydrazine (57-14-7)

Conditions	Yield
bei der elektrolytischen Reduktion;

(Z)-azomethane (4143-42-4) + hydrogen → 1,1-dimethylhydrazine (57-14-7)

Conditions	Yield
at 27℃; Reaktion mit atomarem Wasserstoff;

(Z)-azomethane (4143-42-4) + sodium-amalgam → 1,1-dimethylhydrazine (57-14-7)

1,1-dimethylhydrazine (57-14-7) + acetophenone (98-86-2) → acetophenone 1,1-dimethylhydrazone (28541-43-7)

Conditions	Yield
With trifluoroacetic acid In benzene Reflux; Dean-Stark;	100%
With acetic acid In methanol Reflux;	60%
In methanol at 20℃;	31%

1-Methyl-4-piperidone (1445-73-4) + 1,1-dimethylhydrazine (57-14-7) → 1-methyl-4-piperidone dimethylhydrazone (136415-15-1)

Conditions	Yield
With acetic acid In diethyl ether at 20℃; for 12h;	100%

(2-oxoethyl)phosphonic acid diethyl ester (1606-75-3) + 1,1-dimethylhydrazine (57-14-7) → [2-(dimethyl-hydrazino)-ethyl]-phosphonic acid diethyl ester (127056-04-6)

Conditions	Yield
With magnesium sulfate In dichloromethane at 0℃; for 2h;	100%
With magnesium sulfate In dichloromethane at 25℃; for 48h;

1,3-Bis<(phenylmethyl)thio>-2-propanone (19216-97-8) + 1,1-dimethylhydrazine (57-14-7) → 1,3-bis(benzylthio)acetone dimethylhydrazone (122538-52-7)

Conditions	Yield
With sulfuric acid In ethanol for 7h; Heating;	100%

2,2,-dimethyl-1,3-dioxan-5-one (74181-34-3) + 1,1-dimethylhydrazine (57-14-7) → N'-(2,2-Dimethyl-[1,3]dioxan-5-ylidene)-N,N-dimethyl-hydrazine

Conditions	Yield
In benzene at 20℃; for 6h; Inert atmosphere; Reflux;	100%
for 20h; Heating;	87%

N,N-Dimethyl-2,4-bis(trifluoroacetyl)-1-naphthylamine (115975-33-2) + 1,1-dimethylhydrazine (57-14-7) → N,N-dimethyl-N'-<2,4-bis(trifluoroacetyl)-1-naphthyl>hydrazine (129602-61-5)

Conditions	Yield
In acetonitrile for 4h; Heating;	100%

3,3,3-trifluoro-1-(p-tolyl)propane-1,2-dione (111269-60-4) + 1,1-dimethylhydrazine (57-14-7) → 2-(N',N'-Dimethyl-hydrazino)-3,3,3-trifluoro-2-hydroxy-1-p-tolyl-propan-1-one (133593-18-7)

Conditions	Yield
In dichloromethane at 0℃; for 0.166667h;	100%

3,3,3-Trifluoro-1-o-tolyl-propane-1,2-dione (133593-15-4) + 1,1-dimethylhydrazine (57-14-7) → 2-(N',N'-Dimethyl-hydrazino)-3,3,3-trifluoro-2-hydroxy-1-o-tolyl-propan-1-one (133593-22-3)

Conditions	Yield
In dichloromethane at 0℃; for 0.166667h;	100%

3,3,3-Trifluoro-1-(4-methoxy-phenyl)-propane-1,2-dione (111269-66-0) + 1,1-dimethylhydrazine (57-14-7) → 2-(N',N'-Dimethyl-hydrazino)-3,3,3-trifluoro-2-hydroxy-1-(4-methoxy-phenyl)-propan-1-one (133593-17-6)

Conditions	Yield
In dichloromethane at 0℃; for 0.166667h;	100%

1,1-dimethylhydrazine (57-14-7) + 2-methylphenyl aldehyde (529-20-4) → 2-methylbenzaldehyde N,N-dimethylhydrazone (59670-11-0)

Conditions	Yield
With magnesium sulfate In dichloromethane at 20℃; Inert atmosphere;	100%
With magnesium sulfate In dichloromethane at 20℃; for 16h;	66%

1,1-dimethylhydrazine (57-14-7) + benzyl azide (622-79-7) → benzaldehyde N,N-dimethylhydrazone (1075-70-3)

Conditions	Yield
iron(III) chloride In acetonitrile for 8h; Oxidation; condensation; Heating;	100%
With iron(III) chloride In acetonitrile for 12h; Condensation; Heating;

1,1-dimethylhydrazine (57-14-7) + 1-[(2R,5R)-5-((E)-(R)-5-Benzyloxy-2,4-dimethyl-pent-3-enyl)-5-methyl-tetrahydro-furan-2-yl]-ethanone (500102-99-8) → N'-{1-[5-(5-benzyloxy-2,4-dimethyl-pent-3-enyl)-5-methyl-tetrahydro-furan-2-yl]-ethylidene}-N,N-dimethyl-hydrazine

Conditions	Yield
With chloro-trimethyl-silane In dichloromethane at 0℃;	100%

(E)-2-Heptenal (18829-55-5) + 1,1-dimethylhydrazine (57-14-7) → N'-hept-2-enylidene-N,N-dimethyl-hydrazine

Conditions	Yield
at 0℃;	100%

2-(1-hexynyl)-1-cyclopentenecarboxaldehyde (106180-25-0) + 1,1-dimethylhydrazine (57-14-7) → N'-(2-hex-1-ynyl-cyclopent-1-enylmethylene)-N,N-dimethyl-hydrazine (566190-89-4)

Conditions	Yield
In chloroform at 20℃; for 16h;	100%

1,1-dimethylhydrazine (57-14-7) + (Z)-3-phenylnon-2-en-4-ynal (104429-45-0) → N,N-dimethyl-N'-(3-phenyl-non-2-en-4-ynylidene)-hydrazine (566190-70-3)

Conditions	Yield
In chloroform at 20℃; for 16h;	100%

1,1-dimethylhydrazine (57-14-7) + 2-ethyl-2-nonen-4-ynal (566190-80-5) → N'-(2-ethyl-non-2-en-4-ynylidene)-N,N-dimethyl-hydrazine (566190-81-6)

Conditions	Yield
In chloroform at 20℃; for 16h;	100%

1,1-dimethylhydrazine (57-14-7) + 2-nonen-4-ynal (566190-78-1) → N,N-dimethyl-N'-non-2-en-4-ynylidene-hydrazine (566190-79-2)

Conditions	Yield
In chloroform at 20℃; for 16h;	100%

1,1-dimethylhydrazine (57-14-7) + 2-(2-propenyl)-2-nonen-4-ynal (566190-83-8) → N'-(2-allyl-non-2-en-4-ynylidene)-N,N-dimethyl-hydrazine (566190-86-1)

Conditions	Yield
In chloroform at 20℃; for 16h;	100%

1,1-dimethylhydrazine (57-14-7) + 2-(hex-1-yn-1-yl)-1-cyclohexenecarboxaldehyde (566190-87-2) → N'-(2-hex-1-ynyl-cyclohex-1-enylmethylene)-N,N-dimethyl-hydrazine (566190-88-3)

Conditions	Yield
In chloroform at 20℃; for 16h;	100%

1-cyclohexene-1-carboxaldehyde (1192-88-7) + 1,1-dimethylhydrazine (57-14-7) → 1-cyclohexene-1-carboxaldehyde N,N-dimethylhydrazone (102268-18-8)

Conditions	Yield
	100%

1,1-dimethylhydrazine (57-14-7) + (2,7-di-tert-butyl-9,9-dimethyl)-9H-xanthene-4,5-dicarbaldehyde (650599-75-0) → N'-[2,7-di-tert-butyl-5-(dimethylhydrazonomethyl)-9,9-dimethyl-8a,10a-dihydro-9H-xanthen-4-ylmethylene]-N,N-dimethylhydrazine

Conditions	Yield
In ethanol for 8h; Heating;	100%
In ethanol Heating;

(3R,3aR,8R,8aR)-8-(tert-Butyl-dimethyl-silanyloxy)-3-methyl-octahydro-azulen-5-one (896434-16-5) + 1,1-dimethylhydrazine (57-14-7) → N'-[8-(tert-butyl-dimethyl-silanyloxy)-3-methyl-octahydro-azulen-5-ylidene]-N,N-dimethyl-hydrazine (896434-17-6)

Conditions	Yield
With acetic acid In ethanol at 20℃; for 1h;	100%

2-methyl-4a,9a-dihydro-4H-1,3,5-trioxa-benzocyclohepten-7-one (934278-96-3) + 1,1-dimethylhydrazine (57-14-7) → N,N-dimethyl-N'-(2-methyl-4a,9a-dihydro-4H-1,3,5-trioxa-benzocyclohepten-7-ylidene)-hydrazine (934278-97-4)

Conditions	Yield
In benzene Heating;	100%

allyltriphenylphosphonium bromide (1560-54-9) + 1,1-dimethylhydrazine (57-14-7) → triphenyl[2-methyl-2-(2,2-dimethylhydrazino)ethyl]phosphonium bromide

Conditions	Yield
In chloroform at 20℃; for 96h;	100%

molybdenum pentachloride + 1,1-dimethylhydrazine (57-14-7) → MoCl3NN(CH3)2

Conditions	Yield
In dichloromethane (N2); stirring (-78°C, 0.08 h); warming to room temp., solvent removal (vac.), drying (vac., 0.5 h), pentane addn., stirring (0.2 h), filtn., washing (pentane), drying (vac.);	100%

cyclohexanedione monoethylene ketal (4746-97-8) + 1,1-dimethylhydrazine (57-14-7) → 2-[1,4-dioxaspiro[4.5 ]decan-8-ylidene]-1,1-dimethylhydrazine (1037668-50-0)

Conditions	Yield
In toluene at 20℃; Dean-Stark; Reflux;	100%
In toluene Dean-Stark; Reflux;	100%
With trifluoroacetic acid In benzene Heating;	86%
With toluene-4-sulfonic acid In benzene for 6h; Reflux;
at 20℃; Neat (no solvent);

2-norbornenone + 1,1-dimethylhydrazine (57-14-7) → C9H14N2

Conditions	Yield
Heating;	100%

1-phenylmethyl-4-piperidone (3612-20-2) + 1,1-dimethylhydrazine (57-14-7) → 1-benzyl-4-(2,2-dimethylhydrazono)piperidine (1334292-35-1)

Conditions	Yield
In toluene at 112℃; for 0.5h; Inert atmosphere;	100%
In toluene for 2h; Dean-Stark; Reflux;	100%

tetradecan-2-one (2345-27-9) + 1,1-dimethylhydrazine (57-14-7) → 2-(tetradecan-2-ylidene)-1,1-dimethylhydrazine (1356546-26-3)

Conditions	Yield
In dichloromethane Reflux;	100%
With magnesium sulfate In dichloromethane Inert atmosphere; Reflux;	100%

pyridine-2-carbaldehyde (1121-60-4) + 1,1-dimethylhydrazine (57-14-7) → 2-pyridinecarboxaldehyde N,N-dimethylhydrazone

Conditions	Yield
In methanol at 20℃; Inert atmosphere;	100%
With magnesium sulfate In dichloromethane at 20℃; for 12h;

Upstream product

• 56-23-5 tetrachloromethane 
• 13750-17-9 N,N-dimethylcarbamoyl azide 
• 3201-26-1 1,2,5-trimethyl-2,3-dihydro-1H-pyrazol-3-one 
• 62-75-9 N-Nitrosodimethylamine 
• 1585-74-6 dimethylchloroamine 
• 30980-98-4 Bis--phenyl-boran 
• 2644-70-4 hydrazine hydrochloride 
• 20914-27-6 1-(2,6-dimethylphenyl)-1-methylcyanamide 
• 29817-35-4 1-acetyl-2-methylhydrazine 
• 67-63-0 isopropyl alcohol 
• 67-56-1 methanol 
• 684-26-4 N,N-dimethyl-N',N'-bis(trimethylsilyl)hydrazine 
• 26429-26-5 1,2-dimethyl-1H-pyrazol-2-ium iodide 
• 7647-01-0 hydrogenchloride 

Downstream Products

• 6233-04-1 N',N'-dimethylacetohydrazide 
• 90559-56-1 2-hydroxy-5-nitro-benzaldehyde dimethylhydrazone 
• 75-50-3 trimethylamine 
• 64298-49-3 1-ethyl-1,1-dimethylhydrazinium bromide 
• 1088-03-5 diphenylacetic acid N',N'-dimethyl-hydrazide 
• 24398-55-8 benzophenone N,N-dimethylhydrazone 
• 62054-70-0 2,2-dimethyl-1-(2,4,6-trinitrophenyl)hydrazine 
• 858785-30-5 N'-(5-chloro-2,4-dinitro-phenyl)-N,N'-dimethyl-hydrazine 
• 117864-88-7 S-benzyl-1,1-dimethyl-iso thiosemicarbazide 
• 598-56-1 N,N-dimethyl-ethanamine 
• 3298-49-5 formic acid N',N'-dimethylhydrazide 
• 120972-05-6 thiazolidine-2,4-dione-2-dimethylhydrazone 
• 73747-64-5 dimethylhydrazono-malonic acid diethyl ester 
• 101587-79-5 4,4'-dimethoxybenzophenone N,N-dimethylhydrazone 

Relevant articles and documents

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POLAROGRAPHIC AND VOLTAMMETRIC DETERMINATION OF 1-(2'-NITROPHENYL)-3,3-DIMETHYLTRIAZENE

The polarographic behaviour of 1-(2'-nitrophenyl)-3,3-dimethyltriazene in a mixed aqueos-methanolic solvent was investigated by tast polarography, differential pulse polarography, and fast scan differential pulse voltammetry at a hanging mercury drop electrode.A mechanism is suggested for the reduction of the compound investigated.The optimum conditions were found for the determination of this analyte by tast polarography over the concentration region of 100 to 2 μmol l-1 and by differential pulse polarography or fast scan differential pulse voltammetry at a hanging mercury drop electrode over the region of 100 to 0.2 μmol l-1.Additional sensitivity increase in the last-mentioned technique was achieved by adsorptive accumulation of analyte on the ahnging mercury drop surfase, owing to which the concentration region was depressed to 0.1 - 0.02 μmol l-1.

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Preparation method of PI3K inhibitor

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Interaction between substituted chloramines and liquid ammonia using the indirect Raschig process

In this paper, different hydrazines are synthesised by the indirect Raschig process. This consists of introducing a substituted chloramine (R 1R2NCl) into liquid ammonia under pressure to obtain the corresponding hydrazine (R1R2NNH2). The experimental results, in disagreement with those reported in the literature, lead us to propose a new mechanistic scheme involving a chlorine transfer reaction. Thus, the formation of chloramine (NH2Cl) and the amine (R1R2NH) occurs first. Chloramine reacts immediately with the substituted amine, in agreement with the direct Raschig process, to produce the hydrazine. Under these conditions, the nature of the hydrazine is kinetically controlled by the excess amine. It is then possible to synthesise different hydrazines from the same substituted chloramine. This mechanism is validated by the following syntheses: unsymmetric dimethylhydrazine (UDMH), N-aminopiperidine (NAPP) and N-amino 3-azabicyclo[3.3.0]octane (NAZA).