23617-71-2

Usage

Synthesis Reference(s)

The Journal of Organic Chemistry, 41, p. 2918, 1976 DOI: 10.1021/jo00879a026

InChI:InChI=1/C10H12O2/c1-7-4-5-9(8(2)6-7)10(11)12-3/h4-6H,1-3H3

Upstream product

• 67-56-1 methanol 
• 21900-42-5 2,4-dimethylbenzoyl chloride 
• 108-31-6 maleic anhydride 
• 91416-35-2 (4-Methyl-6-methylene-cyclohexa-2,4-dienylidene)-methanone 
• 109277-68-1 (1R,2S,6S,7R)-7,10-Dimethyl-4,8-dioxa-tricyclo[5.2.2.0^2,6]undec-10-ene-3,5,9-trione 
• 922-67-8 propynoic acid methyl ester 
• 109277-67-0 (1R,2R,6S,7R)-7,10-Dimethyl-8-oxa-4-aza-tricyclo[5.2.2.0^2,6]undec-10-ene-3,5,9-trione 
• 611-01-8 2,4-dimethyl-benzoic acid 
• 126889-61-0 4-methylbenzocyclobuten-1(2H)-one 
• 124-41-4 sodium methylate 
• 186581-53-3 diazomethane 
• 108-38-3 m-xylene 
• 95-68-1 2,4-Xylidine 
• 89-74-7 2,4-dimethylacetophenone. 

Downstream Products

• 54120-64-8 5-methylphthalide 
• 74733-28-1 methyl 4-(bromomethyl)-2-methylbenzoate 
• 63112-94-7 2,4-Dibrommethylbenzoesaeuremethylester 
• 16308-92-2 2,4-dimethylbenzyl alcohol 
• 16054-72-1 Bis-(2,4-dimethylbenzyl)-ether 
• 77837-63-9 (1E,3E)-1-(4-carboxy-3-methylphenyl)-2-methyl-4-(2,6,6-trimethyl-1-cyclohexen-1-yl)-1,3-butadiene 
• 77837-62-8 (1E,3E)-1-(4-carboethoxy-3-methylphenyl)-2-methyl-4-(2,6,6-trimethyl-1-cyclohexen-1-yl)-1,3-butadiene 
• 85304-03-6 2,4-dimethylbenzoylhydrazide 
• 1392227-38-1 (E)-methyl 2-(3-n-butoxy-3-oxoprop-1-en-1-yl)-4,6-dimethylbenzoate 
• 622847-32-9 2-bromomethyl-4-methylbenzoic acid methyl ester 

Relevant academic research and scientific papers

Streamlined Total Synthesis of Uncialamycin and Its Application to the Synthesis of Designed Analogues for Biological Investigations

From the enediyne class of antitumor antibiotics, uncialamycin is among the rarest and most potent, yet one of the structurally simpler, making it attractive for chemical synthesis and potential applications in biology and medicine. In this article we describe a streamlined and practical enantioselective total synthesis of uncialamycin that is amenable to the synthesis of novel analogues and renders the natural product readily available for biological and drug development studies. Starting from hydroxy- or methoxyisatin, the synthesis features a Noyori enantioselective reduction, a Yamaguchi acetylide-pyridinium coupling, a stereoselective acetylide-aldehyde cyclization, and a newly developed annulation reaction that allows efficient coupling of a cyanophthalide and a p-methoxy semiquinone aminal to forge the anthraquinone moiety of the molecule. Overall, the developed streamlined synthesis proceeds in 22 linear steps (14 chromatographic separations) and 11% overall yield. The developed synthetic strategies and technologies were applied to the synthesis of a series of designed uncialamycin analogues equipped with suitable functional groups for conjugation to antibodies and other delivery systems. Biological evaluation of a select number of these analogues led to the identification of compounds with low picomolar potencies against certain cancer cell lines. These compounds and others like them may serve as powerful payloads for the development of antibody drug conjugates (ADCs) intended for personalized targeted cancer therapy.

Series of structural and functional models for the ES (enzyme-substrate) complex of the Co(II)-containing quercetin 2,3-dioxygenase

A series of mononuclear CoII-flavonolate complexes [Co IILR(fla)] (LRH = 2-{[bis(pyridin-2-ylmethyl) amino]methyl}-p/m-R-benzoic acid; R = p-OMe (1), p-Me (2), m-Br (4), and m-NO2 (5); fla = flavonolate) were designed and synthesized as structural and functional models for the ES (enzyme-substrate) complexes to mimic the active site of the Co(II)-containing quercetin 2,3-dioxygenase (Co-2,3-QD). The metal center Co(II) ion in each complex shows a similar distorted octahedral geometry. The model complexes display high enzyme-type dioxygenation reactivity (oxidative O-heterocyclic ring opening of the coordinated substrate flavonolate) at low temperature, presumably due to the attached carboxylate group in the ligands. The reactivity exhibits a substituent group dependent order of -OMe (1) > -Me (2) > -H (3)14b > -Br (4) > -NO2 (5), and the Hammett plot is linear (ρ = -0.78). This can be explained as the electronic nature of the substituent group in the ligands may influence the conformation and redox potential of the bound flavonolate and finally bring different reactivity. The structures, properties, and reactivity of the model complexes show some dependence on the substituent group in the supporting model ligands, and there is some relationship among them. This study is the first example of a series of structural and functional ES models of Co-2,3-QD, with focus on the effects of the electronic nature of substituted groups and the carboxylate group of the ligands to the dioxygenation reactivity, that will provide important insights into the structure-property-reactivity relationship and the catalytic role of Co-2,3-QD.

Isosteric analogs of lenalidomide and pomalidomide: Synthesis and biological activity

A series of analogs of the immunomodulary drugs lenalidomide (1) and pomalidomide (2), in which the amino group is replaced with various isosteres, was prepared and assayed for immunomodulatory activity and activity against cancer cell lines. The 4-methyl and 4-chloro analogs 4 and 15, respectively, displayed potent inhibition of tumor necrosis factor-α (TNF-α) in LPS-stimulated hPBMC, potent stimulation of IL-2 in a human T cell co-stimulation assay, and anti-proliferative activity against the Namalwa lymphoma cell line. Both of these analogs displayed oral bioavailability in rat.

Computational and experimental structure-reactivity relationships: evidence for a side reaction in Alpine-Borane reductions of d-benzaldehydes

Extraordinary stereoselectivity, approaching 100%, has been reported in the reductions of d-benzaldehydes by B-isopinocampheyl-9-borabicyclo[3.3.1]nonane (Alpine-Borane). This is likely because of the extreme size disparity of groups on either side of the carbonyl. Here, we present a structure-reactivity study whereby the reductions of variably substituted d-benzaldehydes are explored using highly sensitive measures for enantiomeric excess and relative reactivity. These results are compared to the relative rates predicted from density functional calculations. The results indicate that 2,6-disubstitution adversely affects the stereoselectivity by means of a non-selective reduction via the dehydroboration product of Alpine-Borane, 9-borabicyclo[3.3.1]nonane.

Stable reagents for the generation of N-centered radicals: Hydroamination of norbornene

(Chemical Equation Presented) Radical transfer hydroaminations have been achieved with 3-aminated 1,4-cyclohexadienes rather than transition-metal reagents (see scheme; DTBP = di-tert-butylperoxide). These functionalized cyclohexadienes are efficient N-radical precursors. Moreover, they are stable and readily prepared, and radical generation occurs under neutral conditions.

13C and 1H nuclear magnetic resonance of methyl-substituted acetophenones and methyl benzoates: Steric hindrance and inhibited conjugation

The 1H and 13C NMR spectra of 14 methyl-substituted acetophenones and 14 methyl-substituted methyl benzoates were assigned and interpreted with respect to the conformation of the Car - C(O) bond. The substituent effects are proportional in the two series and can be divided into polar and steric: each has different effects on the 13C SCS of the individual atoms. In the case of C atoms C(O), C(1) and CH3(CO), the steric effects were quantitatively separated by comparing SCS in the ortho and para positions. The steric effects are proportional for the individual C atoms and also to steric effects estimated from other physical quantities. However, they do not depend simply on the angle of torsion φ of the functional group as anticipated hitherto. A better description distinguishes two classes of compounds: sterically not hindered or slightly hindered planar molecules and strongly sterically hindered, markedly non-planar. In order to confirm this reasoning without empirical correlations, the J(C,C) coupling constants were measured for three acetophenone derivatives labeled with 13C in the acetyl methyl group. The constants confirm unambiguously the conformation of 2-methylacetophenone; their zero values are in accord with the conformation of 2,6-dimethylacetophenone. The zero values in the unsubstituted acetophenone are at variance with previous erroneous report but all J(C,C) values are in accord with calculations at the B3LYP/6-311++G(2d,2p)// B3LYP/6-311+G(d,p) level. Copyright

Regioselectivity of the Base-Induced Ring Cleavage of 1-Oxygenated Derivatives of Cyclobutabenzene

Oxy anions 3 generated from 1,2-dihydrocyclobutabenzen-1-ones 1 through addition of a charged nucleophile or from 1-hydroxy-1,2-dihydrocyclobutabenzenes 2 by deprotonation with base lead to stable products through distal and/or proximal cleavage of the strained four-membered ring via benzyl carbanion 4 and/or aryl carbanion 5. A systematic study of this process reveals the relative stability of the two isomeric carbanions 4 and 5 as a key factor in determining the course of the ring-cleavage reaction. While benzyl carbanions 4 can be trapped with carbon electrophiles, attempts at trapping aryl carbanions 5 with electrophiles other than H+ failed. In protic solvents, the magnesium salt of the tertiary alcohol 2 shows an increased rate of proximal cleavage as compared to its alkali salts. From this, we conclude that, in contrast to benzyl carbanions 4, free aryl carbanions 5 are of transient existence only. Proximal C,C-bond cleavage seems to occur either through protonation of 5 from a fast, reversible equilibrium 3?5 in which 3 strongly predominates, or in protic solvents possibly even through a rate-limiting protonation of 3 at the aromatic C-atom, bypassing free anion 5 altogether. Thus, additional factors other than just the relative stability of isomeric carbanions 4 and 5 are of importance in determining the regiochemistry of the base-induced C,C-bond cleavage in ketones 1 and in alcohols 2.

Aromatic Spiranes XX [1]: Syntheses of Dimethylsubstituted 2-Carboxymethyl-indan-1-ones and Benzylchlorides as Synthones for Syntheses of di- to tetramethylsubstituted Spirobiindandiones

The isomeric dimethyl methylbenzoates 5, obtained from the bromides via Grignard reactions with dimethylcarbonate, were reduced with LiAlH4 to the hydroxymethyl derivatives 6. The latter were then transformed both to the benzylchlorides 7 (with SOCl2) and to the aldehydes 8 (with pyridinium chlorochromate). Knoevenagel-Doebner reaction of 8 afforded the acrylic acids 9 which (after hydrogenation to 11) were cyclized to the desired indanones 12 with polyphosphoric acid. On the other hand, 12c and 12e were prepared from dimethyl 3-chloropropiophenone (14) by warming with sulfuric acid. After NaH-catalyzed reaction with dimethylcarbonate, the indanones 12 gave the ketoesters 15 which then could be hydrogenated to the indanes 16. All reactions proceeded with satisfactory to excellent yields (60-90%).

Concepts of sterically hindered resonance and buttressing effect: Gas-phase acidities of methyl-substituted benzoic acids and basicities of their methyl esters

Two classical terms "Steric Hindrance to Resonance" and "Buttressing Effect" are revisited on the basis of the gas-phase acidities of nine methyl-substituted benzole acids and of the gas-phase basicities of their methyl esters, measured using FT- ICR spectrometry. By combining these data with published heats of formation of the neutrals and by using the principle of isodesmic reactions, relative enthalpies of formation were evaluated separately for the acid molecules, their anions (deprotonated), and their protonated cations (substituted by the protonated forms of the corresponding methyl esters). Energies of all species were also calculated at the semiempirical level (AMI). Substituent effects on the gas-phase acidity are similar to those on the acidity in water. All the methyl groups have a stabilizing polar effect, and o-methyl groups have a destabilizing steric effect, both effects increasing from the deprotonated forms to the acid molecules and then to the protonated forms. Separation of the two effects was attempted, assuming equal polar effects in the ortho and para positions. The results are internally consistent: their detailed analysis is in favor of a primary steric effect rather than a steric inhibition of resonance. The latter must be relatively weaker and operating only in 2,6-dimethyl derivatives, which are certainly nonplanar. In the literature this concept has been used too broadly, even for compounds for which the nonplanar conformation has not been proven. The concept of buttressing effect has been confirmed for methyl-substituted benzoic acids, but it is formulated more generally and more exactly. According to the new definition, it can be observed even for nonadjacent substituants.

Diels-Alder Reactions of Cyclohexadienes Derived from Decarboxylation of Photocycloadducts between 4,6-Dimethyl-2-pyrone and Cyclic Olefins

Labile photo adducts between 4,6-dimethyl-2-pyrone and cyclic olefins reacted with second olefins to give cross adducts, and with acetylenes to afford both bis-adducts and benzene derivatives with the concurrent decarboxylation, respectively.The rea