One-pot parallel synthesis of 1,3,5-trisubstituted 1,2,4-triazoles

An implementation of the three-component one-pot approach to unsymmetrical 1,3,5-trisubstituted-1,2,4-triazoles into combinatorial chemistry is described. The procedure is based on the coupling of amidines with carboxylic acids and subsequent cyclization with hydrazines. After the preliminary assessment of the reagent scope, the method had 81% success rate in parallel synthesis. It was shown that over a billion-sized chemical space of readily accessible ("REAL") compounds may be generated based on the proposed methodology. Analysis of physicochemical parameters shows that the library contains significant fractions of both drug-like and "beyond-rule-of-five" members. More than 10 million of accessible compounds meet the strictest lead-likeness criteria. Additionally, 195 Mln of sp³-enriched compounds can be produced. This makes the proposed approach a valuable tool in medicinal chemistry.

Generating Multibillion Chemical Space of Readily Accessible Screening Compounds

An approach to the generation of ultra-large chemical libraries of readily accessible (“REAL”) compounds is described. The strategy is based on the use of two- or three-step three-component reaction sequences and available starting materials with pre-validated chemical reactivity. After the preliminary parallel experiments, the methods with at least ∼80% synthesis success rate (such as acylation – deprotection – acylation of monoprotected diamines or amide formation – click reaction with functionalized azides) can be selected and used to generate the target chemical space. It is shown that by using only on the two aforementioned reaction sequences, a nearly 29-billion compound library is easily obtained. According to the predicted physico-chemical descriptor values, the generated chemical space contains large fractions of both drug-like and “beyond rule-of-five” members, whereas the strictest lead-likeness criteria (the so-called Churcher's rules) are met by the lesser part, which still exceeds 22 million.

•

A strategy for ultra-large readily accessible (REAL) compound libraries is described

•

Pre-validated two- or three-step three-component reaction sequences are used

•

A 29-billion chemical space with ∼80% synthesis success rate has been easily obtained

One-Pot Parallel Synthesis of 5-(Dialkylamino)tetrazoles

Two protocols for the combinatorial synthesis of 5-(dialkylamino)tetrazoles were developed. The best success rate (67%) was shown by the method that used primary and secondary amines, 2,2,2-trifluoroethylthiocarbamate, and sodium azide as the starting reagents. The key steps included the formation of unsymmetrical thiourea, subsequent alkylation with 1,3-propane sultone and cyclization with azide anion. A 559-member aminotetrazole library was synthesized by this approach; the overall readily accessible (REAL) chemical space covered by the method exceeded 7 million feasible compounds.

SAR by Space: Enriching Hit Sets from the Chemical Space

We introduce SAR by Space, a concept to drastically accelerate structure-activity relationship (SAR) elucidation by synthesizing neighboring compounds that originate from vast chemical spaces. The space navigation is accomplished within minutes on affordable standard computer hardware using a tree-based molecule descriptor and dynamic programming. Maximizing the synthetic accessibility of the results from the computer is achieved by applying a careful selection of building blocks in combination with suitably chosen reactions; a decade of in-house quality control shows that this is a crucial part in the process. The REAL Space is the largest chemical space of commercially available compounds, counting 11 billion molecules as of today. It was used to mine actives against bromodomain 4 (BRD4). Before synthesis, compounds were docked into the binding site using a scoring function, which incorporates intrinsic desolvation terms, thus avoiding time-consuming simulations. Five micromolar hits have been identified and verified within less than six weeks, including the measurement of IC₅₀ values. We conclude that this procedure is a substantial time-saver, accelerating both ligand and structure-based approaches in hit generation and lead optimization stages.

Carbacylamidophosphates: Structure and Properties of Bis(N,N′,-morpholido)-[(N″-morpholido)-carboxamido] phosphate

The bis(N,N′-morpholido)-[(N″-morpholido)-carboxamido] phosphate: O(CH2CH2 )NC(O )-N(H)P(O)[N(CH2CH2 )O]2 [HL], has been prepared and characterized by means of IR, 31P and 1H NMR spectroscopy and X-ray diffraction (triclinic, a = 9.282(2), b = 9.308(2), c = 21.341(4) Å, α = 80.79(3)°, β = 80.92(3)° γ = 66.92(3)°, V = 1665.1(6) Å3, space group P1̄̄, Z = 4 and R = 0.0423, wR2 = 0.1303 for 6774 unique reflections used). The unit cell consists of two independent molecules connected by hydrogen bonds N-H...O=P into non-symmetric dimers. The compound behaves as a HL molecule with a protonation constant corresponding to the -C(O)N(H)P(O)- group of pK = 8.65 as determined by potentiometric studies.

TetramethylN,N′-(2,2,3,3,4,4-hexafluoro-1,5-dioxopentane-1,5-diyl)bis(phosphoramidate)

The molecule of the title compound, C9H14F6N2O8P2, lies on a twofold rotation axis that passes through the middle C atom of the three-atom fluoromethylene unit. The carbonyl and phosphoryl groups are in an antiperiplanar conformation. In the crystal, N—H...O=P hydrogen bonds link the molecules into polymeric chains parallel to thecaxis.