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Biocatalytic Reduction of Organic Compounds by Marine-Derived Fungi
Published in Se-Kwon Kim, Marine Biochemistry, 2023
Gabriel S. Baia, David E. Q. Jimenez, André Luiz Meleiro Porto
Jimenez et al. [24] reported a protocol to obtain E-2-cyano-3(furan-2-yl) acrylamide in the reaction between aromatic aldehydes and cyanoacetamide in yields of up to 95% [24]. The authors used marine-derived fungi to reduce E-2-cyano-3(furan-2-yl) acrylamide at 32°C and 130 rpm in buffer solution (Na2HPO4/KH2PO4) for 3 days to give 92–98% yields and 97 to 99% ee as shown in Figure 15.13. The 2-cyano-3-(furan-2-yl)propanamide undergoes a ketenimine tautomerization in situ to produce an achiral ketenimine in polar solvents.
Chemistry
Published in Stephen P. Coburn, The Chemistry and Metabolism of 4′-Deoxypyridoxine, 2018
Wibaut et al.549 improved the procedure of van Wagtendonk and Wibaut to give an overall yield of 15%. Cyanoacetamide (21 g, 0.25 mole) was dissolved in 150 ml of 96% ethanol and 3 ml of piperidine was added. The solution was brought to gentle reflux and 25 g (0.25 mole) 2,4-pentanedione was slowly added through the condenser. Refluxing was continued for 30 min. After cooling in a refrigerator, 2,4-demethyl-5-cyano-6-hydroxpyridine was collected by suction and washed with 10 mi ice-cold ethanol (yield 36 g [97%]; M.P. 294°C).
Structure-based optimization of type III indoleamine 2,3-dioxygenase 1 (IDO1) inhibitors
Published in Journal of Enzyme Inhibition and Medicinal Chemistry, 2022
Ute F. Röhrig, Somi Reddy Majjigapu, Pierre Vogel, Aline Reynaud, Florence Pojer, Nahzli Dilek, Patrick Reichenbach, Kelly Ascenção, Melita Irving, George Coukos, Olivier Michielin, Vincent Zoete
5-Substituted 4-aryl-1,2,3-triazoles (Table 2) were obtained according to Scheme 3. Phenyl propynenitrile (54) reacted with sodium azide in DMF at 90 °C to produce 6265. Compounds 63 and 68 were obtained from the corresponding aryl benzaldehyde (55a, 55b), nitroethane and ammonium acetate through condensation in presence of acetic acid, followed by dipolar cycloaddition with HN3 engendered with sodium azide and p-toluenesulfonic acid in DMF at 60 °C66. The 4,5-diaryl derivative 64 was obtained from 3-chlorobenzaldehyde (55a) by reaction with tosylhydrazine (57) in ethanol followed by cyclisation with Cs2CO3 at 100 °C in DMF67. The reaction of ethyl 3–(4-chlorophenyl)propiolate (59) with sodium azide in DMSO at 60 °C yielded 6568. The reaction of 2-cyanoacetamide (60) with aryl benzaldehydes (55b, 55c) in the presence of sodium azide and Et3N·HCl allowed the formation of triazoles 66 and 6769.
Structure-guided approach on the role of substitution on amide-linked bipyrazoles and its effect on their anti-inflammatory activity
Published in Journal of Enzyme Inhibition and Medicinal Chemistry, 2022
Souraya A. Domiati, Khaled H. Abd El Galil, Mohammed A. S. Abourehab, Tamer M. Ibrahim, Hanan M. Ragab
The synthesis of the intermediate and target compounds is illustrated in the following scheme (Figure 3). The starting compounds, 5-amino-3-methylsulfanyl-1Hpyrazole-4-carbonitrile (2), and the cyanoacetamide derivative (3) were prepared according to the procedure reported in the literature2,34. The ketene N,S-acetals (4a-e) were prepared through a two-step procedure to prevent hydrolysis of the CN group into the corresponding CONH2. In the first step, the appropriate aryl isothiocyanate was added to an ice-cold mixture of 3 and KOH in DMF at 0–5 °C, cooling was maintained for a further 2 h, then the reaction mixture was allowed to reach room temperature and left for overnight to attain complete reaction with the aryl isothiocyanates. The second step in the afore-mentioned procedure involves the addition of dimethyl sulphate to the reaction to accomplish the final required S-methylation of the products. The obtained products were separated as an oily material that was used as crude without purification to prepare the target compounds 5a-e through their fusion with 4-aminoantipyrine at 170 °C. IR spectra of the final products 5a-e indicated the presence of three NH bands, a signal for the cyano group and two carbonyl signals. 1H-NMR spectra of the synthesised target compounds revealed the presence of three or four singlets equivalent to the three or four aliphatic methyl protons in compounds 5b-d and 5e, respectively. Fourteen aromatic protons appeared as a multiplet and finally, the three D2O exchangeable protons of the three NH groups appeared at their expected downfield shifts (refer to Figure 3).
From cycloheptathiophene-3-carboxamide to oxazinone-based derivatives as allosteric HIV-1 ribonuclease H inhibitors
Published in Journal of Enzyme Inhibition and Medicinal Chemistry, 2019
Serena Massari, Angela Corona, Simona Distinto, Jenny Desantis, Alessia Caredda, Stefano Sabatini, Giuseppe Manfroni, Tommaso Felicetti, Violetta Cecchetti, Christophe Pannecouque, Elias Maccioni, Enzo Tramontano, Oriana Tabarrini
Starting from synthone 3132, synthesised by reacting cycloheptanone with 2-cyanoacetamide, the coupling reaction with the appropriate benzoyl chloride led to the target compounds 7 and 9, and intermediate 32, of which methoxy derivatives 7 and 32 were O-demethylated yielding hydroxy compounds 6 and 8 (Scheme 2).