Abstract: A related substance of linagliptin intermediate 2-(chloromethyl)-4-methylquinazoline, 4,4?-(2-methylpropane-1,3-diyl)bis(2-(chloromethyl)quinazoline) and a method for synthesizing the related substance (impurity) by reacting 2-(chloromethyl)-4-methylquinazoline with acetaldehyde under an alkaline condition and a purification method are provided. The preparation method is simple and convenient to operate, short in reaction time, high in product purity, and high in yield. The synthesized related substance can be used for qualitative and quantitative analysis of the linagliptin intermediate 2-(chloromethyl)-4-methylquinazoline and API impurities of linagliptin, so that the medication safety of the linagliptin is improved.

Abstract: The present disclosure relates to synthesis of an mRNA delivery agent, in particular to a reaction of a related amino compound with ethylene oxide in the presence of ytterbium triflate.

Abstract: A preparation method of an intermediate compound of formula II ((1R,2S,3S,4S,5S,6R,11S,14S,17S,19R,21R,23S,25R,26R,27S,31R,34S)-25-[(2S)-2,3-dihydroxy]-2,5-dihydroxy-26-methoxy-19-methyl-13,20-dimethylene-24,35,36,37,38,39-hexaoxane[29.3.1.13,6.14,34.111,14.117,21.023,27]nonatriacontan-8,29-dione) for eribulin mesylate is provided, including subjecting a compound of formula I to a reaction with an additive in the presence of tetra-n-butylammonium fluoride (TBAF). The additive is piperidine hydrochloride or pyridine hydrochloride, and a reaction formula is as follows: The present invention aims to avoid the problem that a traditional synthetic route has a low yield.

Abstract: A more environmentally friendly synthesis method of 4-bromo-2-(4?-ethoxyphenyl)-1-chlorobenzene with simplified steps provides a more effective synthetic strategy for producing key intermediates of SGLT-2 inhibitors such as dapagliflozin, sotagliflozin, and ertugliflozin. In the presence of trifluoroacetic anhydride, 5-bromo-2-chlorobenzoic acid and phenetole are selected to complete a direct acylation reaction under the catalysis of boron trifluoride diethyl etherate, and triethylsilane is added thereinto without treatment for one-pot reaction to obtain a target compound 4-bromo-2-(4?-ethoxyphenyl)-1-chlorobenzene.

Abstract: A related substance of linagliptin intermediate 2-(chloromethyl)-4-methylquinazoline, 4,4?-(2-methylpropane-1,3-diyl)bis(2-(chloromethyl)quinazoline) and a method for synthesizing the related substance (impurity) by reacting 2-(chloromethyl)-4-methylquinazoline with acetaldehyde under an alkaline condition and a purification method are provided. The preparation method is simple and convenient to operate, short in reaction time, high in product purity, and high in yield. The synthesized related substance can be used for qualitative and quantitative analysis of the linagliptin intermediate 2-(chloromethyl)-4-methylquinazoline and API impurities of linagliptin, so that the medication safety of the linagliptin is improved.

Abstract: A preparation method of an intermediate compound of formula II ((1R,2S,3S,4S,5S,6R,11S,14S,17S,19R,21R,23S,25R,26R,27S,31R,34S)-25-[(2S)-2,3-dihydroxy]-2,5-di hydroxy-26-methoxy-19-methyl-13,20-dimethylene-24,35,36,37,38,39-hexaoxane[29.3.1.13,6.14,34.111,14.117,21.023,27]nonatriacontan-8,29-dione) for eribulin mesylate is provided, including subjecting a compound of formula I to a reaction with an additive in the presence of tetra-n-butylammonium fluoride (TBAF). The additive is piperidine hydrochloride or pyridine hydrochloride, and a reaction formula is as follows: The present invention aims to avoid the problem that a traditional synthetic route has a low yield.

Abstract: A more environmentally friendly synthesis method of 4-bromo-2-(4?-ethoxyphenyl)-1-chlorobenzene with simplified steps provides a more effective synthetic strategy for producing key intermediates of SGLT-2 inhibitors such as dapagliflozin, sotagliflozin, and ertugliflozin. In the presence of trifluoroacetic anhydride, 5-bromo-2-chlorobenzoic acid and phenetole are selected to complete a direct acylation reaction under the catalysis of boron trifluoride diethyl etherate, and triethylsilane is added thereinto without treatment for one-pot reaction to obtain a target compound 4-bromo-2-(4?-ethoxyphenyl)-1-chlorobenzene.

Abstract: A method for preparing tulathromycin, and two intermediate compounds shown in formula V and formula VI are provided.

Abstract: A method for preparing tulathromycin, and two intermediate compounds shown in formula V and formula VI are provided.