Identification and removal of a cryptic impurity in pomalidomide-PEG based PROTAC

• Bingnan Wang,
• Yong Lu and
• Chuo Chen

Beilstein J. Org. Chem. 2025, 21, 407–411, doi:10.3762/bjoc.21.28

• impurity generated in this process. Nucleophilic acyl substitution competes with aromatic substitution to displace glutarimide and gives a byproduct that can co-elute with the desired product on HPLC throughout the remainder of the synthesis. Scavenging with taurine is a convenient way to minimize this

• contamination. Keywords: glutarimide; IMiD; impurity; nucleophilic acyl substitution; PROTAC; Introduction Targeted protein degradation capitalizing on the concept of chemically induced dimerization has emerged as a new therapeutic approach recently [1]. In particular, the modularity of proteolysis targeting

• of 5 using the same sequence of reactions starting from 3-fluorophthalic anhydride instead of 1. Indeed, 5 is a white solid without UV absorption around 410 nm (Figure 2). The formation of 6 originated from nucleophilic acyl substitution to displace the glutarimide in 1 by 2. Interestingly, this side

Oxidative fluorination with Selectfluor: A convenient procedure for preparing hypervalent iodine(V) fluorides

• Samuel M. G. Dearman,
• Xiang Li,
• Yang Li,
• Kuldip Singh and
• Alison M. Stuart

Beilstein J. Org. Chem. 2024, 20, 1785–1793, doi:10.3762/bjoc.20.157

• reported before [26][27][28], we developed a new synthetic route which is shown in Scheme 5. In the first step trifluoromethylketone 17 was prepared by a nucleophilic acyl substitution of methyl 2-iodobenzoate 16 with Ruppert’s reagent. Ketone 17 was then reacted with an excess of Ruppert’s reagent and

Regiodivergent synthesis of functionalized pyrimidines and imidazoles through phenacyl azides in deep eutectic solvents

• Paola Vitale,
• Luciana Cicco,
• Ilaria Cellamare,
• Filippo M. Perna,
• Antonio Salomone and
• Vito Capriati

Beilstein J. Org. Chem. 2020, 16, 1915–1923, doi:10.3762/bjoc.16.158

• ], (c) carbon–sulfur bond-forming reactions [9], (d) directed ortho-metalation and nucleophilic acyl substitution strategies [10], (e) Pd-catalyzed aminocarbonylation of aryl iodides, Suzuki–Miyaura and Sonogashira cross-coupling reactions [11][12][13], (f) Cu-catalyzed C–N coupling reactions [14], and

Quinolines from the cyclocondensation of isatoic anhydride with ethyl acetoacetate: preparation of ethyl 4-hydroxy-2-methylquinoline-3-carboxylate and derivatives

• Nicholas G. Jentsch,
• Jared D. Hume,
• Emily B. Crull,
• Samer M. Beauti,
• Amy H. Pham,
• Julie A. Pigza,
• Jacques J. Kessl and
• Matthew G. Donahue

Beilstein J. Org. Chem. 2018, 14, 2529–2536, doi:10.3762/bjoc.14.229

• trituration with methanol that was determined to be exclusively compound 12 by NMR. The formation of either regioisomer 11 (via b) or 12 (via a) results from 6-exo-trig cyclization of the common nucleophilic acyl substitution intermediate 13. The 13C NMR data of the product has a singlet at δ 199 ppm that

• alkoxide G that undergoes a [1,4]-shift of the silicon group with concomitant ejection of cyanide anion to form acyl cyanide H [33]. As the reaction is run in the presence of ethanol, nucleophilic acyl substitution of cyanide H for the ethoxy group furnishes the ethyl ester 21 in one pot. We were therefore

One-pot odourless synthesis of thioesters via in situ generation of thiobenzoic acids using benzoic anhydrides and thiourea

• Mohammad Abbasi and
• Reza Khalifeh

Beilstein J. Org. Chem. 2015, 11, 1265–1273, doi:10.3762/bjoc.11.141

• [51] or thioacetamide [52], a benzoic anhydride undergoes a nucleophilic acyl substitution reaction with thiourea to produce the corresponding S-benzoylisothiouronium salt as an intermediate. After addition of H2O to the reaction mixture, the salt is hydrolyzed by the hydroxide anion to generate the