A new route for the synthesis of 1-deazaguanine and 1-deazahypoxanthine

• Raphael Bereiter,
• Marco Oberlechner and
• Ronald Micura

Beilstein J. Org. Chem. 2022, 18, 1617–1624, doi:10.3762/bjoc.18.172

• pyrrolopyrimidines) are N-heterocycles that have become an indispensable part of research in medicinal chemistry [1][2][3]. Especially, derivatives of 3-deazaguanine (imidazo[4,5-c]pyridines) [4], 7-deazaguanine/-hypoxanthine (pyrrolo[2,3-d]pyrimidines) [5][6], and 9-deazaguanine/-hypoxanthine (pyrrolo[3,2-d

Synthesis of O⁶-alkylated preQ₁ derivatives

• Laurin Flemmich,
• Sarah Moreno and
• Ronald Micura

Beilstein J. Org. Chem. 2021, 17, 2295–2301, doi:10.3762/bjoc.17.147

• cofactor for methyl group transfer resulting in cytosine methylation. This recently discovered riboswitch-ribozyme activity opens new avenues for the development of RNA labeling tools based on tailored O6-alkylated preQ1 derivatives. Here, we report a robust synthesis for this class of pyrrolo[2,3-d

• ]pyrimidines starting from readily accessible N2-pivaloyl-protected 6-chloro-7-cyano-7-deazaguanine. Substitution of the 6-chloro atom with the alcoholate of interest proceeds straightforward. The transformation of the 7-cyano substituent into the required aminomethyl group turned out to be challenging and was

Microwave-assisted multicomponent reactions in heterocyclic chemistry and mechanistic aspects

• Shivani Gulati,
• Stephy Elza John and
• Nagula Shankaraiah

Beilstein J. Org. Chem. 2021, 17, 819–865, doi:10.3762/bjoc.17.71

• advantage of the synergistic action of the two pharmacophores fused (Figure 7). 6.2.1 Pyrrolo[2,3-d]pyrimidines: Bhuyan and co-workers [80] reported an efficient MWA three-component reaction between N,N-disubstituted-6-aminouracil 86, arylglyoxal monohydrate 33, and amines 32 in AcOH resulting in the

An improved, scalable synthesis of Notum inhibitor LP-922056 using 1-chloro-1,2-benziodoxol-3-one as a superior electrophilic chlorinating agent

• Nicky J. Willis,
• Elliott D. Bayle,
• George Papageorgiou,
• David Steadman,
• Benjamin N. Atkinson,
• William Mahy and
• Paul V. Fish

Beilstein J. Org. Chem. 2019, 15, 2790–2797, doi:10.3762/bjoc.15.271

• air- and moisture-stable. The scope of published substrates includes chlorination of 7H-pyrrolo[2,3-d]pyrimidines and we wished to see if we could extend the scope to include sulphur containing heterocycles such as thieno[3,2-d]pyrimidines (e.g., 6). It was also important to explore if 12 would

Synthesis and fluorescent properties of N(9)-alkylated 2-amino-6-triazolylpurines and 7-deazapurines

• Andrejs Šišuļins,
• Jonas Bucevičius,
• Yu-Ting Tseng,
• Irina Novosjolova,
• Kaspars Traskovskis,
• Ērika Bizdēna,
• Huan-Tsung Chang,
• Sigitas Tumkevičius and
• Māris Turks

Beilstein J. Org. Chem. 2019, 15, 474–489, doi:10.3762/bjoc.15.41

• to increased fluorescence quantum yield (74%) in THF solution. The compounds exhibit low cytotoxicity and as such are useful for the cell labelling studies in the future. Keywords: 7-deazapurines; fluorescence; nucleophilic aromatic substitution; purines; push–pull systems; pyrrolo[2,3-d]pyrimidines

The tert- amino effect in heterocyclic chemistry: Synthesis of new fused pyrazolinoquinolizine and 1,4-oxazinopyrazoline derivatives

• Dipak Prajapati and
• Kalyan Jyoti Borah

Beilstein J. Org. Chem. 2007, 3, No. 43, doi:10.1186/1860-5397-3-43

• undergoing a 1,5-(4 → 5) hydride shift prior to cyclization to yield a 6-membered ring product 6 (Scheme 2). This is in contrast to an earlier report by Sandhu et al to obtain pyrrolo [2,3-d]pyrimidines from 6-tert-amino-substituted uracils and dimethyl acetylenedicarboxylate.[32] However, further work is in