N N

With most methyl esters the hydrazinolysis occurs at room temperature however resin-bound methyl 3-aminobenzoate, ethyl nipecotate, and proline methyl esters require heating (45-50 C) for 7-8 h. Piperazinones (oxopiperazines) readily meet some of the combinatorial chemist's favourite criteria in designing diversity systems for lead finding. The low molecular weight scaffold is amenable to a high degree of straightforward derivatization and allows the incorporation of a richness of amino acid...

Introduction

In order to exploit fully the potential of combinatorial organic synthesis, it is important to automate or at least parallelize all or part of the individual steps. A typical workflow as it is encountered in automated organic (solid-phase) synthesis is shown in Fig. 1. prepare reagent and building block solutions isolate product -evaporation -lyophilization optional purification, e.g. -solid phase extraction -chromatography work up reaction, e.g. -cleavage from support -liquid-liquid extraction...

Condensation reactions

Sb acetophenone + arom. aldehyde, NaOMe sb aldehyde + acetophenone, NaOMe + CH3N02, NH40 Ac HO Ac sb arom. aldehyde + RCOMe, LiOH DME PS DVB-CHO + malonic acid, piperidine sb P-ketoester + aldehyde, piperidine sb malonate + aldehyde, piperidine HOAc + arom. aldehyde, piperidine py + aldehyde, piperidinium acetate sb malonamide + aldehyde, piperidine HOAc sb acetoacetate + aldehyde, piperidinium acetate 384 sb oxindole + arom. aldehyde, pyrrolidine 385 sb cyanoacetamide + aldehyde, piperidine...

Info

a slurry of resin 69 prepared as described in the previous section (R1 propyl, R2 benzyl 1.50 g, -0.75 mmol) inTHF (15 mL) was added (+ -2-bromo-3-methylbutyric acid (1.36 g, 7.5 mmol, 10 equiv.) and DIEA (2.6 mL, 15 mmol, 20 equiv.). PyBrOP (3.5 g, 7.5 mmol, 10 equiv.) was added in one portion to the reaction mixture, which was then agitated at 50 C until a nin-hydrin test confirmed the completion of the acylation (-18 h).The resin was filtered and washed with DMF (2 x 10 mL) and DCM (2 x 10...

Combinatorial Synthesis of Heterocycles

Marzinzik The scope of combinatorial chemistry has broadened to a remarkable extent over the past years, ever since the preparation of a small benzodiazepine library 1 illustrated the applicability of combinatorial synthesis beyond chain-like, oligomeric structures. Although the concepts formulated by Furka in the 1980s 2, 3 appeared to possess broad validity, they were initially a domain of peptide and oligonucleotide chemistry. On one hand the immediate...

Drug Likeness Compound Name

0.558331 0.282134 -0.0212569 -0.273807 -0.326727 -0.276843 -0.206716 -0.0772396 0.0100203 0.043421 0.038305 0.0191716 0.006473 0.001468 0.000125 1.0268 -06 0 0 0 0 Listing 1. Examples for descriptor sets of the drug molecule diclofenac, a) Molecular fingerprints 19 . b) Substructure descriptors 20 . c) Autocorrelation coefficients, based on the three-dimensional interaction potential of the molecule 21 . The most simple filters are calculated directly from the molecular formula, from the...

Nucleophilic aromatic substitutions

Sb nitroarylfluorides + piperazine, NMP 314 sb 3-fluoro-4-nitrophenol + 1 amine, DMSO 315 sb 4-fluoro-3-nitrobenzamide + ethyl 3-aminopropanoate, + amino acid ester, DIEA DMF 85 + 1 amine DMF 281 + -amino acid, NaHC03 H20 acetone 84 sb 4-fluoro-3-nitrobenzoate + amino acid ester, DIEA DMF 93 + 1 amine DMSO 92 sb 4-fluoro-3-nitrobenzoate or - benzamide + 1 amine, sb 4-fluoro-benzoate + piperazine, NMP 82 sb o-difluoroquinolone + piperazine, NMP 256 sb trifluoropyridme + 1 or 2 amine, NMP 319...

Grieco Three Component Reaction

Diels-Alder-type reactions of imines with dienes (Aza Diels-Alder reactions) offer a useful means of preparing nitrogen-containing, six-membered heterocycles 31,32 , Since the imine can be formed from an aldehyde and an amine component, the overall reaction can be performed as a three-component reaction (dubbed the Grieco three-component reaction). Initially, the reaction was performed under Mannich-like conditions. The performance of the reaction could be improved significantly by using...

Electrophilic aromatic substitutions

Sb 1-hydroxyimidazole, ortho-lithiation with nBuLi, then QiCle 327 poly(p-hydroxystyrene)resin + Br2 NBu3 328 PS DVB + Br2 Tl(OAc)3, T1C13 or FeCl3 306 sb 1-hydroxyimidazole, ortho-lithiation with nBuLi, then CBr4 327 conversion of Ar-triazenes to Arl, Mel 202 sb tyrosine derivative + IPy2 BF4 330 8.4.2 Formation and reactions of metalated aromatic compounds 8.4.2.2 Addition to carbonyl compounds PS DVB-Br + nBuLi, then ethylene oxide PS DVB + BuLi TMEDA, then fluorenone 210 PS DVB-Br + nBuLi,...

Nucleophilic aliphatic substitution reactions

+ propargyl bromide, Cs2C03 DMF sb 2 amine + allyl or benzyl bromide, DMF + allyl bromide, Schwesinger base dioxane + benzyl bromide, DBU DMSO + benzyl bromide, DIEA DMF acetone + benzyl chloride, NEt3 sb 2 or 3 amine + alkyl halide, DMF sb 3 amine + allyl or benzyl bromide, DMF + alkyl halide, DMF sb ArNHR + benzyl bromide, DIEA DMF proton sponge DMSO sb indole + alkyl halide, NaH DMF sb tetrahydroisoquinoline + alkyl halide (Br or I), DMF sb xanthine + alkyl halide, NEt3 sb pyridine +...

Equipment for High Throughput Evaporation

For high-throughput evaporation, vacuum centrifuges are currently the devices which are in most widespread use. Recently, equipment using orbital shaking as an alternative has come to the fore. Key issues in both cases are efficient heat transfer to the samples to achieve good evaporation performance, and resistance against the chemicals usually encountered in organic synthesis. To address the first issue, the current centrifuge models manufactured by Savant, Christ and Genevac use IR-lamps...

Multicomponent reactions

Rink amine resin + ArCOOH RCHO RNC, MeOH CHCl, 390 + RCOOH RCHO RNC, MeOH DCM 391 + RCOOH RCOMe RNC 392 + benzoic acid RCHO RNC 393 + RCOOH RCHOAVeinreb amide isonitrile, MeOH DCM 347 sb amine + RCOOH RCHO PhNC or 2-pyNC, MeOH CHClj py 394 + RCOOH RCHO (either one a C-glycoside) RNC, sb amino acid ester + RCOOH RCHO RNC, MeOH 396 sb pyrimidine carboxylic acid + RNH2 RCHO RNC, dioxane MeOH 275 from sb RNC + ArCOCHO RNH2 RCOOH 397 5- and 6-membered lactams from sb RNC + sb ArNC + RCHO RNH2 RCOOH,...

Rcoome To Rch2oh

8.10.2.1 Reactions of nitrile oxides from sb nitrile oxide gen. from nitroalkane alkene 364,370,371 from sb nitrile oxide gen. from hydroximoyl chloride alkene 180 from sb nitrile oxide gen. from aldoxime alkene 426 isoxazoles from sb nitrile oxide gen. from hydroximoyl chloride alkyne 180 isoxazolines from sb alkene nitrile oxide gen. from isoxazolines isoxazoles from sb alkene alkyne nitrile oxide gen. from nitroalkane 79 isoxazoles from sb alkyne nitrile oxide gen. from nitroalkane or oxime...

Rs 232

septum covers or self-closing flaps for rvs available temperature time programs possible inert atmosphere in rv possible comes with reflux option built-in timer can turn heating on off at specified time built-in timer can turn heating on off at specified time STEM RS heat stir STEM chill stir glass vials or tubes held glass vials or tubes held glass tubes vials 16,20 glass tubes vials 16,20 glass vials tubes 16 mm in aluminum block in aluminum 12 24 x 150 mm or 24 10 or 18 ml 24 16 X 100 mm or...

Tfa

R2CHO, CH30 3HC O V I.BocHN COOH Scheme 9. Synthesis of diketopiperazines. Cyclative cleavage The resin 35 200 mg was shaken in toluene ortoluene ethanol 1 1 2 mL in the presence of 1 acetic acid or 4 triethylamine at room temperature for several hours 8-12 h for acidic conditions, 2-5 h for basic conditions .The resin was washed several times with ethanol, the combined filtrates were concentrated to give 36 16 . In a similar strategy, a-hydroxy acids were bound to substituted amino...