7 results about "Methyl derivative" patented technology

This invention discloses a method for synthesizing medroxyprogesterone acetate intermediates based on a metal-organic synergistic catalysis. The method uses 17-acetyl-10,13-dimethyl-3-oxo-2,3,6,7,8,9,10,11,12,13,14,15,16,17-tetradecano-1H-cyclopenta[a]phenanthrene-17-yl acetate as a starting material. Under the synergistic catalytic system composed of a chiral α-amino acid (such as L-proline) and a Lewis acid metal salt (such as zinc acetate), it reacts with a secondary amine and a formaldehyde source to selectively prepare a 6-methylene derivative. This invention utilizes the regio-directing effect of amino acids and the activating and stabilizing effect of metal ions to significantly suppress C2-position side reactions and dimer formation, resulting in a product yield exceeding 93% and a purity exceeding 99%. Column chromatography is not required, making it suitable for large-scale industrial production.

A method of synthesising a IN-alkyl derivative of pseudouridine comprises contacting a substrate with a methyltransferase in the presence of a cofactor to produce the I N-alkylderivative of pseudourid

The present application relates to a kind of 2-oxazolidinone-3-carbamimidate-5-methylene derivatives and preparation method thereof, belong to organic synthesis technical field.The structure of 2-oxazolidinone-3-carbamimidate-5-methylene derivatives provided in the present application is as shown in formula (I)-(III).2-Oxazolidinone-3-carbamimidate-5-methylene derivatives of the present application can be applied to the synthesis and activity screening of novel oxazolidinone antibiotics, can provide technical support for the further derivatization and biological activity research of 2-oxazolidinone-3-carbamimidate derivative compound, with wide application prospect.

The invention discloses a method for preparing 5-fluorosalicylaldehyde from p-fluorophenol, and belongs to the technical field of organic synthesis. A mild formylation method is realized by innovatively adopting a catalyst and an active methylene derivative (POCl3 + DMF) as a C1 source. According to the method, p-fluorophenol is taken as a raw material, in the presence of a catalytic amount of titanium tetrachloride, p-fluorophenol, phosphorus oxychloride and N, N-dimethylformamide are subjected to Vilsmeier-Haack reaction in dichloromethane to synthesize p-fluorobenzaldehyde, and then a methanol-water recrystallization process is adopted to replace distillation for purification. Core improvements include: (1) titanium tetrachloride catalyzes Vilsmeier-Haack reaction, and by-products are few; (2) the temperature is controlled by stages, and the operation is easy to control; (3) directly dropwise adding reaction liquid to hydrolyze at 10-25 DEG C; and (4) methanol / water recrystallization purification. According to the method, the defects of a traditional process are overcome, the purity of a crude product reaches 85%-92%, the purity after recrystallization is larger than or equal to 98.5%, the yield is stabilized at 88%-91%, and the method is easy and convenient to operate, low in energy consumption, environmentally friendly and easy to industrialize.

The present invention concerns aza-metal-dipyrromethene derivatives, processes of production and uses thereof in photocatalysis.