A simple synthesis of 4-(2-aminoethyl)-5-hydroxy-1H-pyrazoles

Kralj, David; Grošelj, Uroš; Meden, Anton; Dahmann, Georg; Stanovnik, B.; Svete, Jurij

doi:10.1016/j.tet.2007.07.052

Cited by 17 publications

(18 citation statements)

References 37 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…5, 43.8, 51.5, 114.9, 127.6/127.6, 127.8, 128.2, 128.3, 128.7/128.7, 129.0, 135.6, 137.8/137.8, 140.4/140.4, 144.0, 148.4 2, 35.7, 43.5, 46.6, 115.0, 127.6, 127.8, 128.7, 137.8, 140.3, 143.9, 148.4 = 11.4, 21.4, 22.9, 41.3, 43.9, 51.5, 115.2, 128.1, 128.2, 129.0, 135.7, 140.3, 143.7, 148.4, 162.3 3d CDCl 3 δ H = 0.96 (3 H, t, J = 7.4 Hz, CH 2 CH 3 ), 1.61 (2 H, sext, J = 7.3 Hz, CH 2 CH 2 CH 3 ), 3. 18 (3 H, s, NCH 3 ), 3.35 (2 H, br q, J = 6.8 Hz, NHCH 2 CH 2 ), 3.45 (2 H, t, J = 6.9 Hz, 4-CH 2 ), 3.60 (2 H, t, J = 6.6 Hz, 5-CH 2 ), 6.52 (1 H, br t, J = 4.9 Hz, NH), 7.92 (1 H, s, 2-H) δ C = 11.5, 21.3, 22.9, 35.8, 41.2, 46.7, 115.3, 140.3, 143.5, 148.5, 162 4, 39.1, 43.8, 51.5, 58.9, 71.0, 115.0, 128.1, 128.2, 128.9, 135.7, 140.3, 143.7, 148.4, 162.2…”

Section: Amentioning

confidence: 99%

Synthesis of 6-Alkyl-7-oxo-4,5,6,7-tetrahydropyrazolo[1,5-c]pyrimidine-3-carboxamides

et al. 2014

Self Cite

View full text Add to dashboard Cite

Two variants of the synthesis of 6-alkyl-7-oxo-4,5,6,7-tetrahydropyrazolo[1,5-c]pyrimidine-3-carboxamides have been developed. The first pathway comprises nine steps starting with the introduction of the 6-alkyl group (R 1 ) via addition of a primary alkylamine to methyl acrylate followed by a seven-step transformation into the 6-benzyl-7-oxo-4,5,6,7-tetrahydropyrazolo[1,5-c]pyrimidine-3-carboxylic acid, which is then amidated into title compounds. The other variation is based on an analogous four-step transformation of Boc-β-alanine into a 6-unsubstituted benzyl ester as the key intermediate. The 6-alkyl group (R 1 ) is then introduced by N-alkylation with alkyl halides, followed by O-debenzylation to give the carboxylic acids, and amidation. A library of 18 title carboxamides was prepared in very good yields.

show abstract

Section: Amentioning

confidence: 99%

Synthesis of 6-Alkyl-7-oxo-4,5,6,7-tetrahydropyrazolo[1,5-c]pyrimidine-3-carboxamides

et al. 2014

Self Cite

View full text Add to dashboard Cite

show abstract

“…In the last decade, the synthesis of aminoethyl functionalized heterocycles has represented an important part of our research studies. Within this context, we have been so far focused on the synthesis of two types of 2-(heteroaryl) ethylamines: a) the open-chain analogues of histamine, 1, [10][11][12][13] and bicyclic conformationally constrained analogues of histamine, 2-4, [14][15][16] and b) 2-substituted 6-(5-oxo-1phenylpyrrolidin-3-yl)pyrimidine-5-carboxamides, 5, as 2aminoethyl-functionalized pyrimidines [17]. In continuation, we have focused our attention on 2-substituted 6-(5-oxo-1phenylpyrrolidin-3-yl)pyrimidin-4(3H)-ones, 6, as novel type of 2-aminoethyl-functionalized pyrimidines (Scheme 1).…”

Section: Introductionmentioning

confidence: 99%

Synthesis of 2-substituted 6-(5-oxo-1-phenylpyrrolidin-3-yl)pyrimidin-4(3H)-ones

et al. 2013

Self Cite

View full text Add to dashboard Cite

KEYWORDS 2-Substituted 6-(5-oxo-1-phenylpyrrolidin-3-yl)pyrimidin-4(3H)-ones were synthesized in three steps from itaconic acid derivatives via cyclization with primary amines followed by Masamune-Claisen condensation, and cyclization of the newly formed β-keto esters with amidines. Preparation and/or isolation of β-keto esters with polar N-substituents failed, but the corresponding final products were obtained in a different way. 6-(1-(3-Hydroxypropyl)-5oxopyrrolidin-3-yl)-2-phenylpyrimidin-4(3H)-one was obtained by hydrogenolytic odeprotection of its o-benzyl derivative. Depending on reaction conditions, further mesylation of 6-(1-(3-(benzyloxy)propyl)-5-oxopyrrolidin-3-yl)-2-phenylpyrimidin-4(3H)-one followed by treatment with pyrrolidine gave either the monoaminated-or the diaminated product. The structures of novel compounds were determined by NMR. Lactams Cyclization HeterocyclesMedicinal chemistry Nitrogen heterocycles Nucleophilic substitution

show abstract

“…In this context, we first reported the synthesis of non-racemic 1-heteroaryl-2-phenylethylamines 1 – 3 from α-amino acid derived enaminoketones [16]. Further, the syntheses of the pyrazole analogues of histamine were developed: 2-aminoethyl substituted 1 H -pyrazole derivatives 4 – 6 as the open-chain analogues [17,18,19,20] and 6,7-dihydro-1 H -pyrazolo[4,3- c ]pyridin-4(5 H )-one derivatives 7 [21], 5-(2-aminophenyl)pyrazole derivatives 8 [22], and 5-(5-oxo-1-phenylpyrrolidin-3-yl)-1 H -pyrazole-4-carboxamides 9 [23] as the conformationally constrained analogues of histamine. In continuation, we have focused our attention on 2-substituted 6-(5-oxo-1-phenylpyrrolidin-3-yl)pyrimidine-5-carboxamides 10 (Figure 1).…”

Section: Introductionmentioning

confidence: 99%

Parallel Synthesis of 2-Substituted 6-(5-Oxo-1-phenylpyrrolidin-3-yl)pyrimidine-5-carboxamides

et al. 2012

Self Cite

View full text Add to dashboard Cite

Abstract:A library of 24 6-(5-oxo-1-phenylpyrrolidin-3-yl)pyrimidine-5-carboxamides 10{1,2; 1-12} was prepared by a parallel solution-phase approach. The synthesis comprises a five-step transformation of itaconic acid (11) into 1-methyl and 1-phenyl substituted 6-(5-oxo-1-phenylpyrrolidin-3-yl)pyrimidine-5-carboxylic acids 17{1,2} followed by parallel amidation of 17{1,2} with a series of 12 aliphatic amines 18{1-12} to afford the corresponding carboxamides 10 in good overall yields and in 80-100% purity.

show abstract

A simple synthesis of 4-(2-aminoethyl)-5-hydroxy-1H-pyrazoles

Cited by 17 publications

References 37 publications

Synthesis of 6-Alkyl-7-oxo-4,5,6,7-tetrahydropyrazolo[1,5-c]pyrimidine-3-carboxamides

Synthesis of 6-Alkyl-7-oxo-4,5,6,7-tetrahydropyrazolo[1,5-c]pyrimidine-3-carboxamides

Synthesis of 2-substituted 6-(5-oxo-1-phenylpyrrolidin-3-yl)pyrimidin-4(3H)-ones

Parallel Synthesis of 2-Substituted 6-(5-Oxo-1-phenylpyrrolidin-3-yl)pyrimidine-5-carboxamides

Contact Info

Product

Resources

About

A simple synthesis of 4-(2-aminoethyl)-5-hydroxy-1H-pyrazoles

Cited by 17 publications

References 37 publications

Synthesis of 6-Alkyl-7-oxo-4,5,6,7-tetrahydropyrazolo[1,5-c]pyri­midine-3-carboxamides

Synthesis of 6-Alkyl-7-oxo-4,5,6,7-tetrahydropyrazolo[1,5-c]pyri­midine-3-carboxamides

Synthesis of 2-substituted 6-(5-oxo-1-phenylpyrrolidin-3-yl)pyrimidin-4(3H)-ones

Parallel Synthesis of 2-Substituted 6-(5-Oxo-1-phenylpyrrolidin-3-yl)pyrimidine-5-carboxamides

Contact Info

Product

Resources

About

Synthesis of 6-Alkyl-7-oxo-4,5,6,7-tetrahydropyrazolo[1,5-c]pyrimidine-3-carboxamides

Synthesis of 6-Alkyl-7-oxo-4,5,6,7-tetrahydropyrazolo[1,5-c]pyrimidine-3-carboxamides