Structure of a 4-nitroso-5-aminopyrazole and its salts: Tautomerism, protonation, and E/Z isomerism

M H Holschbach; D Sanz; R M Claramunt; L Infantes; S Motherwell; P R Raithby; M L Jimeno; D Herrero; L Alkorta; N Jagerovic; J Elguero

doi:10.1021/jo034833u

Structure of a 4-nitroso-5-aminopyrazole and its salts: Tautomerism, protonation, and E/Z isomerism

M H Holschbach, D Sanz, R M Claramunt, L Infantes, S Motherwell, P R Raithby, M L Jimeno, D Herrero, L Alkorta, N Jagerovic, J Elguero

Department of Chemistry

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21 Citations (SciVal)

Abstract

The structures of 1-benzyl-4-nitroso-5-aminopyrazole (1) and its hydrochloride (1H(+)) have been determined in the solid state and in solution in DMSO, methanol, and ethanol. The free base exists in solution as a mixture of amino/nitroso tautomers 2a and 2b rather than in the imino/oxime tautomers 3. The conjugated cation 1H(+) results from the protonation of the nitroso group. X-ray crystallography showed that both amino hydrogen atoms of 2a form NH...O=N hydrogen bonds: one is intramolecular, the other links adjacent molecules in an infinite chain.

Original language	English
Pages (from-to)	8831-8837
Number of pages	7
Journal	Journal of Organic Chemistry
Volume	68
Issue number	23
DOIs	https://doi.org/10.1021/jo034833u
Publication status	Published - 2003

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ID number: ISI:000186489000012

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title = "Structure of a 4-nitroso-5-aminopyrazole and its salts: Tautomerism, protonation, and E/Z isomerism",

abstract = "The structures of 1-benzyl-4-nitroso-5-aminopyrazole (1) and its hydrochloride (1H(+)) have been determined in the solid state and in solution in DMSO, methanol, and ethanol. The free base exists in solution as a mixture of amino/nitroso tautomers 2a and 2b rather than in the imino/oxime tautomers 3. The conjugated cation 1H(+) results from the protonation of the nitroso group. X-ray crystallography showed that both amino hydrogen atoms of 2a form NH...O=N hydrogen bonds: one is intramolecular, the other links adjacent molecules in an infinite chain.",

author = "Holschbach, {M H} and D Sanz and Claramunt, {R M} and L Infantes and S Motherwell and Raithby, {P R} and Jimeno, {M L} and D Herrero and L Alkorta and N Jagerovic and J Elguero",

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doi = "10.1021/jo034833u",

language = "English",

volume = "68",

pages = "8831--8837",

journal = "Journal of Organic Chemistry",

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publisher = "American Chemical Society",

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TY - JOUR

T1 - Structure of a 4-nitroso-5-aminopyrazole and its salts: Tautomerism, protonation, and E/Z isomerism

AU - Holschbach, M H

AU - Sanz, D

AU - Claramunt, R M

AU - Infantes, L

AU - Motherwell, S

AU - Raithby, P R

AU - Jimeno, M L

AU - Herrero, D

AU - Alkorta, L

AU - Jagerovic, N

AU - Elguero, J

N1 - ID number: ISI:000186489000012

PY - 2003

Y1 - 2003

N2 - The structures of 1-benzyl-4-nitroso-5-aminopyrazole (1) and its hydrochloride (1H(+)) have been determined in the solid state and in solution in DMSO, methanol, and ethanol. The free base exists in solution as a mixture of amino/nitroso tautomers 2a and 2b rather than in the imino/oxime tautomers 3. The conjugated cation 1H(+) results from the protonation of the nitroso group. X-ray crystallography showed that both amino hydrogen atoms of 2a form NH...O=N hydrogen bonds: one is intramolecular, the other links adjacent molecules in an infinite chain.

AB - The structures of 1-benzyl-4-nitroso-5-aminopyrazole (1) and its hydrochloride (1H(+)) have been determined in the solid state and in solution in DMSO, methanol, and ethanol. The free base exists in solution as a mixture of amino/nitroso tautomers 2a and 2b rather than in the imino/oxime tautomers 3. The conjugated cation 1H(+) results from the protonation of the nitroso group. X-ray crystallography showed that both amino hydrogen atoms of 2a form NH...O=N hydrogen bonds: one is intramolecular, the other links adjacent molecules in an infinite chain.

U2 - 10.1021/jo034833u

DO - 10.1021/jo034833u

M3 - Article

SN - 0022-3263

VL - 68

SP - 8831

EP - 8837

JO - Journal of Organic Chemistry

JF - Journal of Organic Chemistry

IS - 23

ER -

Structure of a 4-nitroso-5-aminopyrazole and its salts: Tautomerism, protonation, and E/Z isomerism

Abstract

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