This invention belongs to the modern pharmaceutical field of Traditional Chinese Medicine, and relates to an herbal extract of Chinese Motherwort and its application in pharmacy, which specifically relates to the crystal structure of a Chinese Motherwort extract: Leonurine, and its application in the preparation of medicine. The chemical name of the above-mentioned Leonurine is 4-guanidino-1-)butyl 4-hydroxy-3,5-dimethoxybenzoate. The invention by specific methods prepares leonurine as 6 kinds of crystals with different crystal forms. Specifically, there are six different structures of leonurine sulfate crystals, two of them are hydrate, two are anhydrous crystal form, one is methanol solvate, one is ethanol solvate. The leonurine crystal forms of this invention can applicate in preparing medicine such as insulin sensitizer, hypoglycemic and lipid-lowering drugs. The above mentioned insulin sensitizers are particularly useful in treating insulin resistance syndrome, and the above mentioned lipid-lowering drugs are useful in the treatment of disorders of lipid metabolism, hyperlipidemia and their complications.

The present invention provides a continuous solvent free and additive free process for the synthesis of Metformin Hydrochloride in a screw reactor. >90% conversion of the solid substrates without solvent is obtained in a screw reactor to produce Metformin Hydrochloride with at least 90% selectivity.

The present invention provides a continuous solvent free and additive free process for the synthesis of Metformin Hydrochloride in a screw reactor. >90% conversion of the solid substrates without solvent is obtained in a screw reactor to produce Metformin Hydrochloride with at least 90% selectivity.

The present invention provides a continuous solvent free and additive free process for the synthesis of Metformin Hydrochloride in a screw reactor. >90% conversion of the solid substrates without solvent is obtained in a screw reactor to produce Metformin Hydrochloride with at least 90% selectivity.

The present invention relates to novel aminoguanidine hydrazone-derivatives of Formula (I) which are effective as retromer stabilizers and useful as neuroprotecting drugs. The invention also relates to pharmaceutical compositions comprising the compounds and their use in therapy and diagnostic.

##STR00001##

The present invention relates to novel aminoguanidine hydrazone-derivatives of Formula (I) which are effective as retromer stabilizers and useful as neuroprotecting drugs. The invention also relates to pharmaceutical compositions comprising the compounds and their use in therapy and diagnostic.

##STR00001##

The present disclosure provides a preparation method for metformin hydrochloride. The preparation method includes: microwave heating raw materials containing dicyandiamide and dimethylamine hydrochloride, and reacting the two at 100° C. to 160° C. to obtain a product system containing metformin hydrochloride. Microwave heating is adopted to heat the dicyandiamide and the dimethylamine hydrochloride. Compared with a conventional heating mode that requires heat to be gradually transferred from the outside to the inside, microwave heating can directly heat each part inside the reactant, which can make the internal temperature of the reactant more uniform, thereby reducing the generation of impurities.

The present disclosure provides a preparation method for metformin hydrochloride. The preparation method includes: microwave heating raw materials containing dicyandiamide and dimethylamine hydrochloride, and reacting the two at 100° C. to 160° C. to obtain a product system containing metformin hydrochloride. Microwave heating is adopted to heat the dicyandiamide and the dimethylamine hydrochloride. Compared with a conventional heating mode that requires heat to be gradually transferred from the outside to the inside, microwave heating can directly heat each part inside the reactant, which can make the internal temperature of the reactant more uniform, thereby reducing the generation of impurities.

The present disclosure discloses a compound 1,1,3,3-tetramethylguanidine (R)-(tert-butoxycarbonyl)(2-(5-(2-fluoro-3-methoxyphenyl)-3-(2-fluoro-6-(trifluoromethyl)benzyl)-4-methyl-2,6-dicarbonyl-3,6-dihydropyrimidine-1(2H)-yl)-1-phenylethyl) sulfamate (of structural formula I) and a preparation method thereof.

##STR00001##

The present disclosure provides purified forms of iobenguane and preparations of a precursor to iobenguane, such as a polymer, the polymer comprising a monomer of formula (I) ##STR00001##
or a pharmaceutically acceptable salt thereof, the preparation comprising leachable tin at a level of 0 ppm to 850 ppm.