24324-17-2Relevant articles and documents
Formation and verification of the structure of the 1-fluorenylmethyl chloroformative derivative of sulfamethazine
Liang,Zhang,Baker,Cross
, p. 86 - 92 (1996)
Sulfamethazine (SMZ) is derivatized with 1-fluorenylmethyl chloroformate (FMOC) to form the fluorescent adduct SMZ-FMOC. Conditions for formation are optimized with respect to pH, reagent concentration, and reagent ratio. Reagent and product profiles (including the hydrolysis byproduct FMOC-OH) versus time are followed by reversed phase HPLC with UV absorbance detection. FMOC-SMZ has been crystallized, its composition confirmed by microanalysis, and its structure corroborated by IR and NMR spectroscopy. From 10 down to 1 ppm, there is clear gentle curvature in the fluorescence intensity of SMZ-FMOC. The linear response range extends from above 100 ppb down to about 100 ppt, and an increase in sensitivity for the fluorescent detection of FMOC-SMZ (over the usual UV absorbance detection of SMZ) is calculated to be better than 3 orders of magnitude.
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Brown,Bluestein
, (1943)
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Me3SI-promoted chemoselective deacetylation: a general and mild protocol
Gurawa, Aakanksha,Kashyap, Sudhir,Kumar, Manoj
, p. 19310 - 19315 (2021/06/03)
A Me3SI-mediated simple and efficient protocol for the chemoselective deprotection of acetyl groups has been developedviaemploying KMnO4as an additive. This chemoselective deacetylation is amenable to a wide range of substrates, tolerating diverse and sensitive functional groups in carbohydrates, amino acids, natural products, heterocycles, and general scaffolds. The protocol is attractive because it uses an environmentally benign reagent system to perform quantitative and clean transformations under ambient conditions.
Preparation method of 9-hydroxymethyl-fluorene diacid
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Paragraph 0039-0045; 0062-0063; 0068-0069; 0074-0075, (2020/12/10)
The invention provides a method for preparing 9-hydroxymethyl-fluorene diacid. The method comprises the following steps: (1) subjecting fluorene to reacting with paraformaldehyde to generate 9-hydroxymethylfluorene; (2) enabling the 9-hydroxymethylfluorene to react with acetyl chloride to generate (2,7-diacetyl-9H-fluoren-9-yl)methyl acetate; (3) enabling the (2,7-diacetyl-9H-fluoren-9-yl)methyl acetate to react with bromine to generate (2,7-bis(2,2-dibromoacetyl)-9H-fluoren-9-yl)methyl acetate; (4) enabling the(2,7-bis(2,2-dibromoacetyl)-9H-fluoren-9-yl)methyl acetate to react with bromine and sodium carbonate to generate 9-(acetoxymethyl)-9H-fluorene-2,7-dicarboxylic acid; and (5) subjecting 9-(acetoxymethyl)-9H-fluorene-2,7-dicarboxylic acid to reacting with an acidic solution to generate 9-hydroxymethyl-fluorene diacid. The method has the advantages of simple preparation process, accessible raw materials and high yield, and lowers the production cost of 9-hydroxymethyl-fluorene diacid.
Additive-free cobalt-catalysed hydrogenation of carbonates to methanol and alcohols
Ferretti, Francesco,Scharnagl, Florian Korbinian,Dall'Anese, Anna,Jackstell, Ralf,Dastgir, Sarim,Beller, Matthias
, p. 3548 - 3553 (2019/07/10)
Reduction of various organic carbonates to methanol and alcohols can be achieved in the presence of a molecularly-defined homogeneous cobalt catalyst. Specifically, the use of Co(BF4)2 in combination with either commercial or tailor-made tridentate phosphine ligands allows for additive-free hydrogenations of carbonates. Optimal results are obtained at relatively mild conditions (120 °C, 50 bar hydrogen pressure) in the presence of xylyl-Triphos L4.
