[107-15-3]  · C2H8N2  · 1,2-Diaminoethane  · (MW 60.10) (.H2O)

[6780-13-8]  · C2H10N2O  · 1,2-Diaminoethane  · (MW 78.11)

(base and reducing agent;1 used to complex metal ions;2 used as building block for linking chains;3 used to prepare imidazolines,4 pyrazines,5 1,4-diazepine derivatives,6 N2n-containing macrocycles,7 and fused heterocycles8)

Alternate Names: DAE; ethylenediamine; EDA.

Physical Data: mp 8.5 °C; bp 117 °C; d204 0.8977 g cm-3; n20D 1.4568.

Solubility: sol H2O and alcohol; slightly sol Et2O (1:300).

Form Supplied in: colorless liquid, widely available.

Purification: for some applications, 1,2-diaminoethane must be dried by standard methods used for amines.9,11

Handling, Storage, and Precautions: the reagent has low toxic, genotoxic, and oncogenic activity and should be handled with caution.10a-c

Complexation of Metal Ions.

1,2-Diaminoethane forms stable complexes with heavy metal ions: Ag, Au, Cd, Co, Cr, Cu, Fe, Hg, Ni, Zn, and others. Complexes of DAE with CdII, CoII, CuII, or HgII are used in quantitative analysis of this metal or, conversely, of DAE. Ten- to 18-membered macrocycles with 2n nitrogen atoms, which can be prepared from the reagent, selectively form polydentate complexes with metal ions.2 These complexes have been used for specific goals in catalytic reactions. For example, CuII complexed with the Shiff base prepared from DAE and chiral aldehydes shows high enantioselectivity in catalytic cyclopropanations of styrene with ethyl diazoacetate.12 Copper(II) complexes of chiral diaminodiamides [HXNHCH2CH2XH (X = Ala, Phe, Val)] have been used for enantioselective recognition of amino acids.13 Addition of DAE after reactions of aryl halides with CuCN facilitates isolation of the nitrile from the reaction mixture by removing the CuII as a complex.14

Chromium(II) salts, with DAE as a ligand added in situ, are easily prepared reducing agents. The DAE greatly enhances the ability of CrII to reduce primary alkyl halides to alkanes,15a and aryl bromides or iodides to arenes (100%).15b This complex in aqueous DMF will selectively reduce a bridgehead chloride (eq 1),15c and convert b-substituted alkyl halides and epoxides to alkenes at rt in high yields.15b 4-R-D1,8-b-Octalones (R = CH2OH, CO2H) have been reduced by a Chromium(II) Sulfate-DAE complex with cis stereospecificity, to the saturated ketones in 90% yield.16

Complex with Borane.

The 1:1 complex of B2H6 with DAE in THF is a highly selective reducing agent, exhibiting reactivity comparable to Sodium Borohydride. For example, it will transform cinnamaldehyde to cinnamyl alcohol.17

Solutions of KI3 in DAE will iodinate phenols, anilines, tyrosines, pyrrole, and hydroxybenzoic acids.18

With Lithium in Reductions.

Lithium in DAE is a powerful reducing system. Reduction of alkenes, aromatic hydrocarbons, phenols, and alcohols have been reported. An example, the reduction of tetralin to octalin, is shown in eq 2.1a The 16,17 double bond and 20-keto group in pregnadienone were reduced to give the (20R)-alcohol in 95% yield.19 Reduction of the 3a,4a- and 3b,4b-epoxides of friedel-3-ene,20a or the epoxides of pinene,20b gave the corresponding alcohols.


The lithium salt of DAE (LiNHCH2CH2-NH2) is a very strong base. It has been used in the dehydrogenation and aromatization of vinylcyclohexene derivatives (4-vinylcyclohexene, limonene; 75-91%).1b Rapid and quantitative isomerization of terminal alkenes to internal alkenes has also been described (eq 3).1b Migration of triple bonds to terminal positions can also be accomplished. Internal alkynic hydrocarbons or alcohols are easily (40-50 °C, 20 min) transformed to terminal isomers in yields of 74-87%.21a The yield of the terminal isomer can be raised by increasing base concentration and using nonpolar solvents.21b This reagent even rapidly shifts two triple bonds to terminal positions in 70-75% yields (eq 4).22a,b Similar migration of triple bonds is observed with Sodium Amide in DAE.23

Building Block for Synthesis.

The synthetic significance of DAE is based on specific features of its structure. The reagent reacts with electrophiles to give mono or bis derivatives. For example, DAE has been monoacylated to give 2-(t-butoxycarbonylamino)ethylamine.24 Reaction of the amino group and subsequent removal of the protecting group reveals a new amine which can be used in the next stage of a synthesis.

DAE has been used as a symmetric building block for the linking of molecular fragments by 1,2-bisamino,3a,b 1,2-bisimino,3c 1,2-bisamido,3d 1,2-bisimido,25 or dimethylene chains (eqs 5 and 6).26

DAE is an excellent synthon for the synthesis of heterocycles with two nitrogen atoms. Condensation of DAE with 4-dialkylamino-3-butyn-2-ones led to 2-acetonylimidazoline (70%).27a Similar reactions with 1-haloalkynes give 2-alkylideneimidazolidines27b or 2-alkylimidazolines.27c Substituted 2-methyleneimidazolines can be prepared from DAE and compounds of the type R(W)C=CX2, as outlined in eq 7.28

Reaction of DAE with acids,4a esters,4b amides,4c dithioesters,4d imidoesters,4e nitriles,4d,f 2-aryloxazolines,4g or 2-phenylthiazolium salts4h gives 2-substituted imidazolines (eqs 8-10).

Imidazoline-2-thiol has been prepared in 60% yield by condensation of DAE with CS2.29 2-Methylimidazole has been prepared in three steps from DAE and acetic acid in an overall yield of 80%.30

Cyclic guanidines have been prepared from DAE and O-alkyl thiocarbamates31a or N-aryldithiocarbamates.31b Similarly, these compounds have been obtained from DAE and imidoyl chlorides32a,b or dialkyl thioacetals of isothiocyanates (eq 11).32c

Reactions of DAE with dialdehydes, diketones, dicarboxylic acids, and their derivatives lead to cyclic products, containing (N-C-C-N)n fragments (eq 12). Thus 1,2-dicarbonyl compounds (a-diketones, o-quinones, alkyl oxalates) gave dihydropyrazines and, after subsequent oxidation, pyrazines.5 Tetrahydropyrazines were obtained from a-halo carbonyl compounds.33a Piperazines were formed from vic-diols and DAE in the presence of a ruthenium catalyst.33b 1,4-Diazepines were prepared from the reaction of DAE with 1,3-diketones,6a vinyl ketones,6b or enynes.6c Twelve- to 20-membered macro N4-heterocycles have been synthesized by the reaction a,o-dicarbonyl compounds with two molecules of DAE.7 This method has been used to prepare some macrocycles with unique abilities for complexation of ions.2

Molecules with two reaction sites react with DAE to give bicyclic products. Heterocycles prepared in this manner include pyrrolo[1,2-a]imidazoles,8a imidazo[3,4-a]imidazoles,8b imidazo[1,2-b]isoquinolines,8c and imidazo[1,2-c]pyrimidines.8d Polycyclic condensed systems with pyrazine34a,b and 1,4-diazepine34c substructures have been synthesized by means of DAE. An example is shown in eq 13.35

1. (a) Reggel, L.; Friedel, R. A.; Wender, I. JOC 1957, 22, 891. (b) Reggel, L.; Friedman, S.; Wender, I. JOC 1958, 23, 1136.
2. (a) Costes, J.-P. Polyhedron 1987, 6, 2169. (b) Mandal, S. K.; Nag, K. JOC 1986, 51, 3900. (c) Harries, H. J.; Moorcroft, G.; Burgess, J. J. Inorg. Nuclear Chem. 1978, 40, 352.
3. (a) Zankowska-Jasinska, W.; Borowiec, H.; Burgiel, M.; Kolasa, A.; Wodzien, M. Pol. J. Chem. 1988, 62, 777 (CA 1990, 112, 118 558x). (b) Moazzam, M.; Parrick, J. J. Pure Appl. Sci. 1988, 7, 25 (CA 1990, 112, 7004u). (c) Handyside, T. M.; Lockhart, J. C.; McDonnell, M. B.; Rao, P. V. S. JCS(D) 1982, 2331. (d) Helpern, J. A.; Sparrow, J. T. SC 1980, 10, 569.
4. (a) Vorbrüggen, H.; Krolikiewicz, K. TL 1981, 22, 4471. (b) Belov, P. S.; Adzhiev, A. Yu.; Frolov, V. I.; Bulanova, E. P.; Isagulyants, V. I. Izv. Vyssh. Uchebn. Zaved. 1977, 20, 371 (CA 1977, 87, 135 192f). (c) Eremeev, A. V.; Tikhomirov, D. A.; Shubina, Yu. V. KGS 1980, 1064. (d) Levesque, G.; Gressier, J.-C.; Proust, M. S 1981, 963. (e) Huang, Z.; Liu, Z. S 1987, 357. (f) Abdelrazek, F. M.; Kandeel, Z. El-S.; Hilmy, K. M. H.; Elnagdi, M. H. CI(L) 1983, 439. (g) Chadwick, D. J.; Ennis, D. S. T 1991, 47, 9901; (h) Singh, H.; Sarin, R. IJC(B) 1986, 25B, 81.
5. (a) Bergeron, R. J.; Hoffman, P. JOC 1980, 45, 161. (b) Liao, C.-C.; Hsieh, H.-P.; Lin, S.-Y. CC 1990, 545.
6. (a) Opozda, E.; Sledziewska, E. JPR 1991, 333, 601. (b) Zimmer, H.; Amer, A.; Ho, D.; Palmer-Sungail, R. JHC 1991, 28, 1501. (c) Sokolova, E. A.; Maretina, I. A.; Petrov, A. A. JOU 1983, 19, 1388. (d) Owczarek, M.; Kostka, K. Pol. J. Chem. 1991, 65, 345. (e) Saloutin, V. I.; Skryabina, Z. E.; Burgart, Y. V. JFC 1991, 56, 325.
7. (a) Moberg, C.; Wärnmark, K.; Csöregh, I.; Ertan, A. JOC 1991, 56, 3339. (b) Kawasaki, Y.; Okuda, N. CL 1982, 1161.
8. (a) Sedavkina, V. A.; Lizak, I. V.; Sorokin, N. N. KGS 1987, 1405. (b) Yamamoto, T.; Imagawa, M. T.; Yabe, Y. T.; Suwabe, E. M.; Muraoka, M. JCS(P1) 1990, 3003. (c) Nagarajan, K.; Rao, V. R.; Shah, R. K.; Shenoy, S. J.; Fritz, H.; Richter, W. J.; Muller, D. HCA 1988, 71, 77. (d) Singh, H.; Kumar, S. JCS(P1) 1987, 261. (e) Leistner, S.; Guetschow, M.; Vieweg, H.; Wagner, G.; Strohscheidt, T.; Grupe, R. Pharmazie 1988, 43, 756 (CA 1989, 110, 173 187j).
9. (a) Bailar, J. C. JACS 1934, 56, 955. (b) Organic Solvents; Riddick, J. A.; Toops, E. E., Eds. Interscience: New York, 1955; pp 239, 444.
10. (a) Slesinski, R. S.; Guzzie, P. J.; Hengler, W. C.; Watanabe, P. G.; Woodside, M. D.; Yang, R. S. H. Mutat. Res. 1983, 124, 299 (CA 1984, 100, 81 067k). (b) De Pass, L. R.; Fowler, E. H.; Yang, R. S. H. Fundam. Appl. Toxicol. 1984, 4, 641 (CA 1984, 101, 124 642j). (c) US NTIS, PB Rep. 1976, PB-267224, from Gov. Rep. Announce Index (US) 1977, 77, 105 (CA 1977, 87, 205 863b).
11. Zgoda, M.; Petri, S. Chem. Anal. 1983, 28, 111 (CA 1984, 100, 209 107t.
12. Brunner, H.; Wutz, K. NJC 1992, 16, 57.
13. Armani, E.; Marchelli, R.; Dossena, A.; Casnati, G.; Dallavalle, F. HCA 1986, 69, 1916.
14. Friedman, L.; Schechter, H. JOC 1961, 26, 2522.
15. (a) Kochi, J. K.; Mocadlo, P. E. JACS 1966, 88, 4094. (b) Kochi, J. K.; Singleton, D. M.; Andrews, L. J. T 1968, 24, 3503. (c) Okamura, W. H.; Monthony, J. F.; Beechan, C. M. TL 1969, 1113.
16. Thompson, H. W.; Shah, N. V. JOC 1983, 48, 1325.
17. Kelly, H. C.; Edwards, J. O. JACS 1960, 82, 4842.
18. Potts, K. T. JCS 1953, 3711.
19. Sengupta, P.; Sen, M.; Sarkar, A.; Das, S. IJC(B) 1986, 25B, 975.
20. (a) Sengupta, P.; Das, K.; Das, S. IJC(B) 1985, 24B, 1175. (b) Gurudutt, K. N.; Rao, S.; Shaw, A. K. IJC(B) 1991, 30B, 345.
21. (a) Remizova, L. A.; Kryukov, A. V.; Balova, I. A.; Favorskaya, I. A. ZOR 1985, 21, 1001. (b) Mostamandi, A.; Remizova, L. A.; Yakimovich, L. V.; Favorskaya, I. A. ZOR 1981, 17, 1166.
22. (a) Remizova, L. A.; Balova, I. A.; Favorskaya, I. A. JOU 1986, 22, 2209. (b) Balova, I. A.; Remizova, L. A.; Makarycheva, V. F.; Rumyantseva, E. G.; Favorskaya, I. A. JOU 1991, 27, 55.
23. Wotiz, J. H.; Barelski, P. M.; Koster, D. F. JOC 1973, 38, 489.
24. Krapcho, A. P.; Kuell, C. S. SC 1990, 20, 2559.
25. Hassan, M. A.; Zayed, S. E.; El-Gazivi, W. N.; Metwally, S. A. AP 1991, 324, 185.
26. Sha C.-K.; Tsou, C. P. JOC 1990, 55, 2446.
27. (a) Ostroumov, I. G.; Tsil'ko, A. E.; Maretina, I. A.; Petrov, A. A. JOU 1988, 24, 1049. (b) Tikhomirov, D. A.; Slyaderskaya, O. S.; Eremeev, A. V. KGS 1991, 1205. (c) Mirscova, A. N.; Seredkina, S. G.; Kalikhman, I. D.; Bannikova, O. B.; Voronkov, M. G. IZV 1989, 906.
28. (a) Nguyen, N. V.; Baum, K. TL 1992, 33, 2949. (b) Dölling, W.; Khoudary, K.; Augustin, M. JPR 1989, 331, 573. (c) Huang, Z.-T.; Liu, Z. SC 1989, 19, 943. (d) Wang, H.; Wang, X.-J.; Huang, Z.-T. CB 1990, 123, 2141. (e) Huang, Z.-T.; Shi, X. SC 1990, 20, 1321.
29. Bhat, A. R.; Subramanian, S. S.; Thomas, J. K. Indian Drugs 1982, 19, 480 (CA 1983, 98, 107 213x).
30. Kraft, M. Ya.; Kochergin, P. M.; Tsyganova, A. M.; Shlikhunova, V. S. Khim.-Farm. Zh. 1989, 23, 1246 (CA 1990, 112, 216 784).
31. (a) Reynaud, P.; Brion, J. D.; Davrinche, C.; Phan-Chi-Dao JHC 1980, 17, 1789. (b) Merchan, F.; Garin, J.; Martinez, V.; Melendez, E. S 1982, 482.
32. (a) Kalkote, U. R.; Brahme, K. C.; Ayyangar, N. R. IJC(B) 1991, 30B, 1133. (b) Ried, W.; Erle, H. E. CB 1982, 115, 475. (c) Fukada, N.; Hayashi, M.; Suzuki, Y. BCJ 1985, 58, 3379.
33. (a) Johnson, J. E.; Maia, J. A.; Tan, K.; Ghafouripour, A.; De Meester, P.; Chu, S. S. C. JHC 1986, 23, 1861. (b) Jenner, G.; Bitsi, G. J. Mol. Catal. 1988, 45, 165.
34. (a) Likhosherstov, A. M.; Peresada, V. P.; Vinokurov, V. G.; Skoldinov, A. P. JOU 1986, 22, 2341. (b) Kallmayer, H. J.; Stass, C. Pharm. Acta Helv. 1989, 64, 248. (c) Eichhorn, T. A.; Piesch, S.; Ried, W. HCA 1988, 71, 988.
35. Urleb, U.; Stanovnik, B.; Tišler, M. JHC 1990, 27, 643.

Rafael R. Kostikov

The St Petersburg State University, Russia

Copyright 1995-2000 by John Wiley & Sons, Ltd. All rights reserved.