The present invention relates to a technique for flow crystallization. The system comprises a container having a bottom surface defining a first plane, the container including at least two planar magnetic surfaces being arranged in a spaced-apart manner along a first plane and being substantially parallel to a second plane; a magnetization vector of each of the magnetic surfaces being perpendicularly to the surface, wherein the container is configured such that the first plane is substantially perpendicularly to the second plane; wherein a cavity formed in between the planar magnetic surfaces is configured to accommodate a racemic mixture including different enantiomers such that each magnetic surface interacts differently with each of the different enantiomers to thereby enable enantio-selective crystallization. Therefore, the system of the present invention is based on enantio-separation of the crystals using magnetic surfaces.

The present invention relates to crystalline 1,2-Propanediol solvate of N-(2-chloro-6-methylphenyl)-2-[[6-[4-(2-hydroxyethyl)-1-piperazinyl]-2-methyl-4-pyrimidinyl]amino]-5-thiazolecarboxamide compound of formula-1b, its process for the preparation and its use in the preparation of anhydrous crystalline form (N-6) and monohydrate of N-(2-chloro-6-methylphenyl)-2-[[6-[4-(2-hydroxy ethyl)-1-piperazinyl]-2-methyl-4-pyrimidinyl]amino]-5-thiazolecarboxamide. [formula] 1,2-Propanediol solvate Formula-1b. ##STR00001##

The present invention relates to a processes for the preparation of 2-{4-[(5,6-diphenyl pyrazin-2-yl)(isopropyl)amino]butoxy}-N-(methylsulfonyl)acetamide compound of formula-1 and novel polymorphs thereof.

Provided is a purifying method for dabigatran etexilate free base, comprising subjecting a dabigatran etexilate free base crude product to water slurrying to obtain a crude product B; then conducting recrystallization on the crude product B with acetone and water to obtain a crude product C; and subsequently, purifying the crude product C with a mixed solvent of tetrahydrofuran and ethyl acetate, filtering and drying to obtain a dabigatran etexilate free base finished product. The purifying method of the present invention can effectively remove various impurities and is suitable for workshop production. Salts and water-soluble organic impurities are removed by purified water slurrying, impurities with a high polarity are removed by purifying with an acetone-water solution, and impurities with a low polarity are removed by purifying with a mixed solvent of tetrahydrofuran and ethyl acetate.

A method of isolating and purifying ()-Ambrox from a reaction mixture comprising ()-Ambrox and one or more of the compounds (II), (III) and (IV) ##STR00001##

The present invention includes compositions and methods for preparing micron-sized or submicron-sized particles by dissolving a water soluble effective ingredient in one or more solvents; spraying or dripping droplets solvent such that the effective ingredient is exposed to a vapor-liquid interface of less than 50, 100, 150, 200, 250, 200, 400 or 500 cm.sup.1 area/volume to, e.g., increase protein stability; and contacting the droplet with a freezing surface that has a temperature differential of at least 30 C. between the droplet and the surface, wherein the surface freezes the droplet into a thin film with a thickness of less than 500 micrometers and a surface area to volume between 25 to 500 cm.sup.1.

The present invention provides a method for extracting Tremella polysaccharides by using buffer solution, which comprises the following steps: leaching Tremella powder in a buffer solution with heating to obtain the leachate; subjecting the said leachate to solid-liquid separation and obtaining the liquid component which contains Tremella polysaccharides; subjecting the said liquid component to alcohol precipitation, and the precipitate obtained is Tremella polysaccharides. According to the method of the invention, various buffer solutions can achieve the extraction rates of Tremella polysaccharides up to 33:12%, which is 3 to 4 times of that of the traditional water extraction method, and greatly improve the extraction yields of Tremella polysaccharides.

Crystal forms I and II of tasimelteon. Crystal form I: an X-ray powder diffraction spectrum using CuK radiation and represented by a 2 angle has diffraction peaks at least at 7.20.2, 7.90.2, 10.60.2, 14.40.2, 15.90.2, 17.30.2, 21.00.2, 23.20.2, and 24.40.2. Crystal form II: an X-ray powder diffraction spectrum using CuK radiation and represented by a 2 angle has diffraction peaks at least at 6.80.2, 12.10.2, 12.50.2, 13.10.2, 13.60.2, 13.80.2, 15.80.2, 17.00.2, 18.40.2, 20.80.2, 24.20.2, and 24.40.2. Crystal forms I and II of tasimelteon have advantages of excellent physicochemical property, good stability and solubility, and simple operation for preparation.

This disclosure provides a process for preparing 1-(arylmethyl)quinazoline-2,4(1H,3H)-diones, specially provides a method for preparing the compound of Formula I, and the method comprises the step of reacting the compound of Formula II with the compound of Formula A in the presence of a condensation agent, an organic base and an organic solvent by condensation.

##STR00001##

An etching solution recycling system for a wafer etching apparatus is provided. The etching solution recycling system includes a settling tank, a seed provider, and a fluid control unit. The settling tank is connected to an etching tank of the wafer etching apparatus and configured to receive an etching solution from the etching tank. The seed provider is configured to provide at least one seed crystal into the settling tank to reduce the silicate concentration in the etching solution in the settling tank. The fluid control unit is configured to deliver the etching solution in the settling tank back into the etching tank.