93-26-5Relevant articles and documents
A Mild Heteroatom (O -, N -, and S -) Methylation Protocol Using Trimethyl Phosphate (TMP)-Ca(OH) 2Combination
Tang, Yu,Yu, Biao
, (2022/03/27)
A mild heteroatom methylation protocol using trimethyl phosphate (TMP)-Ca(OH)2combination has been developed, which proceeds in DMF, or water, or under neat conditions, at 80 °C or at room temperature. A series of O-, N-, and S-nucleophiles, including phenols, sulfonamides, N-heterocycles, such as 9H-carbazole, indole derivatives, and 1,8-naphthalimide, and aryl/alkyl thiols, are suitable substrates for this protocol. The high efficiency, operational simplicity, scalability, cost-efficiency, and environmentally friendly nature of this protocol make it an attractive alternative to the conventional base-promoted heteroatom methylation procedures.
Continuous synthesis method 2 -acetylamino -5 - nitroanisole
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Paragraph 0035, (2021/11/03)
The invention mainly relates to the field of organic synthesis, and discloses a continuous synthesis process for 2 -acetylamino -5 - nitroanisole. The process takes a microchannel continuous flow reactor as a main reaction device, and anthranilic acid is taken as a starting raw material and is subjected to preacylation. And nitration, a continuous synthesis 2 - acetylamino -5 - nitroanisole was achieved. To the process, the compound amidation reagent is adopted, the raw material cost is reduced, and the amidation reagent and the reaction solvent are unified. The continuous production process and equipment are introduced, continuous production is realized, the automation degree is improved, and the production safety risk is greatly reduced. The reaction time, the generation of by-products and the subsequent treatment difficulty are reduced, the nitration selectivity is improved, the economic benefits and environmental benefits are achieved, and the development concept of the green chemistry is met.
Paracetamol and other acetanilide analogs as inter-molecular hydrogen bonding assisted diamagnetic CEST MRI contrast agents
Chakraborty, Subhayan,Peruncheralathan,Ghosh, Arindam
, p. 6526 - 6534 (2021/02/21)
Paracetamol and a few other acetanilide derivatives are reported as a special class of diamagnetic Chemical Exchange Saturation Transfer (diaCEST) MRI contrast agents, that exhibit contrast only when the molecules form inter-molecular hydrogen bonding mediated molecular chains or sheets. Without the protection of the hydrogen bonding their contrast producing labile proton exchanges too quickly with the solvent to produce any appreciable contrast. Through a number of variable temperature experiments we demonstrate that under the conditions when the hydrogen bond network breaks and the high exchange returns back, the contrast drops quickly. The well-known analgesic drug paracetamol shows 12% contrast at a concentration of 15 mM at physiological conditions. With the proven safety track-record for human consumption and appreciable physiological contrast, paracetamol shows promise as a diaCEST agent forin vivostudies.
