We wanted to search for new reaction conditions to prepare the title compounds, to be checked later in novel syntheses of heterocyclic compounds. To the best of our knowledge, there was no report in the literature of any well-established method for the preparation of N-(2-phenoxyethyl)anilines 1.Facultad de Ciencias Exacta

Autino, Juan Carlos

Guaymas, O.

Jios, Jorge L.

Piovoso, R.

Romanelli, Gustavo Pablo

Molecules

Servicio de Difusión de la Creación Intelectual

Molecules 2000, 5 562A Simple Method for N-Phenoxyethylation of AnilinesG. P. Romanelli, J. L. Jios, O. Guaymas, R. Piovoso and J. C. AutinoLADECOR, Departamento de Química, Facultad de Ciencias Exactas, Universidad Nacional de LaPlata. Calles 47 y 115, B1900AJL La Plata, ArgentinaE-mail: jautino@quimica.unlp.edu.arAbstract: We wanted to search for new reaction conditions to prepare the title compounds,to be checked later in novel syntheses of heterocyclic compounds. To the best of our knowl-edge, there was no report in the literature of any well-established method for the preparationof N-(2-phenoxyethyl)anilines 1.The scarce previously reported preparations involved large excesses of some starting materials,relatively high temperatures and long reaction times [1, 2]. We have recently reported a general proce-dure for that preparation [3] although at that stage only moderate yields were obtained. We describehere a better and simpler procedure for achieving not only compounds 1 in good yields, but also forextending the scope of the reaction to the synthesis of the related bis-N-(2-phenoxy-ethyl)anilines 2. Inorder to avoid β-elimination reactions in molecules bearing a phenoxyethyl group, the reaction wascarried out precluding strong acidic or basic media, see Scheme.NH2R1OBrR2R1NOYR24 1: Y = H; 2: Y = -CH2-CH2O- R2anh. K2CO3 / DMSOScheme. N-phenoxyethylation reaction of anilines.Dependimng on the product desired,  1-bromophenoxyethanes (3) or anilines (4) were used in molarexcess. To prepare mono-N-(2-phenoxyethyl)anilines (1) the reagent 4 was used in excess, yielding 70-80% (see Table), whereas an excess of 3 lead to 2 with yields ranging in 50-70%.Reaction conditions involve typically 90°C, DMSO as solvent and anhydrous K2CO3 as the base.Yields are substantially improved as compared with those already obtained using triethylamine [3].New compounds 2b and 2c gave satisfactory analytical and spectroscopic data.Molecules 2000, 5 563Table. Selected examples of N-(2-phenoxyethyl)anilines 1 and 2.Compound R1 R2 % Yield1a H H 751b H OMe 721c H NO2 711d OMe H 791e NO2 H 582a H H 552b H Cl 592c Cl H 63References and Notes1. Oki, M.; Mutai, K. Intramolecular N-H...O hydrogen bonding in N-(ω-phenoxyalkyl)anilines.Spectrochim. Acta 1969, A25, 1941.2. Mutai, K.; Tukada, H.; Nakagaki, R. Bifunctional Reactivity of the Nitrophenoxyl Group in In-tramolecular Photoreactions. J. Org. Chem. 1991, 56, 4896.3. Autino, J. C.; Bruzzone, L.; Romanelli, G. P.; Jios, J. L.; Ancinas, H. A. Substituted N-phenoxyethylanilines: preparation and acid-base properties evaluation by fluorescence spec-trometry. Anales de Química, Intern. Ed. 1998, 94, 292.

A simple method for <i>N</i>-phenoxyethylation of anilines

SEDICI - Repositorio de la UNLP

Molecules 2000, 5 562
A Simple Method for N-Phenoxyethylation of Anilines
G. P. Romanelli, J. L. Jios, O. Guaymas, R. Piovoso and J. C. Autino
LADECOR, Departamento de Química, Facultad de Ciencias Exactas, Universidad Nacional de La
Plata. Calles 47 y 115, B1900AJL La Plata, Argentina
E-mail: jautino@quimica.unlp.edu.ar
Abstract: We wanted to search for new reaction conditions to prepare the title compounds,
to be checked later in novel syntheses of heterocyclic compounds. To the best of our knowl-
edge, there was no report in the literature of any well-established method for the preparation
of N-(2-phenoxyethyl)anilines 1.
The scarce previously reported preparations involved large excesses of some starting materials,
relatively high temperatures and long reaction times [1, 2]. We have recently reported a general proce-
dure for that preparation [3] although at that stage only moderate yields were obtained. We describe
here a better and simpler procedure for achieving not only compounds 1 in good yields, but also for
extending the scope of the reaction to the synthesis of the related bis-N-(2-phenoxy-ethyl)anilines 2. In
order to avoid β-elimination reactions in molecules bearing a phenoxyethyl group, the reaction was
carried out precluding strong acidic or basic media, see Scheme.
NH2
R1
O
Br
R2
R1
N
O
Y
R2
4 1: Y = H; 2: Y = -CH2-CH2O- R2
anh. K2CO3 / DMSO
Scheme. N-phenoxyethylation reaction of anilines.
Dependimng on the product desired,  1-bromophenoxyethanes (3) or anilines (4) were used in molar
excess. To prepare mono-N-(2-phenoxyethyl)anilines (1) the reagent 4 was used in excess, yielding 70-
80% (see Table), whereas an excess of 3 lead to 2 with yields ranging in 50-70%.
Reaction conditions involve typically 90°C, DMSO as solvent and anhydrous K2CO3 as the base.
Yields are substantially improved as compared with those already obtained using triethylamine [3].
New compounds 2b and 2c gave satisfactory analytical and spectroscopic data.
Molecules 2000, 5 563
Table. Selected examples of N-(2-phenoxyethyl)anilines 1 and 2.
Compound R1 R2 % Yield
1a H H 75
1b H OMe 72
1c H NO2 71
1d OMe H 79
1e NO2 H 58
2a H H 55
2b H Cl 59
2c Cl H 63
References and Notes
1. Oki, M.; Mutai, K. Intramolecular N-H...O hydrogen bonding in N-(ω-phenoxyalkyl)anilines.
Spectrochim. Acta 1969, A25, 1941.
2. Mutai, K.; Tukada, H.; Nakagaki, R. Bifunctional Reactivity of the Nitrophenoxyl Group in In-
tramolecular Photoreactions. J. Org. Chem. 1991, 56, 4896.
3. Autino, J. C.; Bruzzone, L.; Romanelli, G. P.; Jios, J. L.; Ancinas, H. A. Substituted N-
phenoxyethylanilines: preparation and acid-base properties evaluation by fluorescence spec-
trometry. Anales de Química, Intern. Ed. 1998, 94, 292.


English

http://sedici.unlp.edu.ar/bitstream/handle/10915/35015/Documento_completo.pdf?sequence=1

A simple method for <i>N</i>-phenoxyethylation of anilines

Abstract

Similar works

Full text

Available Versions

Servicio de Difusión de la Creación Intelectual

SEDICI - Repositorio de la UNLP