Disclosed are a method for preparing an imidazole derivative and crystal form A and crystal form B thereof, and also disclosed is a method for preparing a compound of formula (I) and an intermediate thereof.

##STR00001##

The present specification discloses methods of purifying one or more cannabinoids from a plant material using unique biphasic solvent systems and liquid-liquid chromatography as centrifugation partitioning chromatography (CPC) or counter current chromatography (CCC). The present specification also provides purified cannabinoids such as CBG, CBGA, CBGV, CBD, CBDA, CBDV, THC, THCA and THCV, compositions comprising one or more of these cannabinoids produced by the disclosed method, and methods for treating a disease or condition employing such purified cannabinoids and compositions.

A process to treat water includes adding a salt-forming base to the water thereby producing saline water, or thereby forming a salt in the water which is different from a salt that the water started out with, if the water started out as saline. The saline water is treated, at a temperature T1 which is above the saturation temperature of the saline water, in a first membrane separation stage to provide clean water and a first brine, the salinity of the first brine being higher than the salinity of the saline water. The first brine is cooled to a temperature T2 to precipitate some of the salt from the first brine and the precipitated salt is separated from the first brine producing a second brine, the temperature T2 being below the temperature T1 but above the freezing temperature of the first brine. The second brine is treated at a temperature T3 above the saturation temperature of the second brine in a second membrane separation stage to provide clean water and a third brine. The salt-forming base, the temperature T1 and the temperature T2 are selected so that the salt which is formed in the saline water has a solubility in water at the temperature T1 which is at least 1.5 times the solubility of the salt in water at the temperature T2.

There is disclosed a process for the separation of long chain amino acid and long chain dibasic acid, comprising: (1) recovering alkylamine from an aqueous solution of an alkali hydroxide hydrolysis of the mixed amide derivatives by distilling or by extracting with an extractant solvent; (2) cooling the aqueous solution of step (1) to precipitate a mixed alkali salts of long chain amino acid and dibasic acid; (3) recovering the mixed alkali salts of long chain amino acid and dibasic acid to provide a mother liquor; (4) separating long chain amino acid and dibasic acid by acidification-extraction of long chain dibasic acid with an extractant solvent or by selective dissolution of alkali salt of long chain amino acid in an aqueous solvent; and (4) adding an acid to the mother liquor of step (3) to obtain alkanoic acid.

There is disclosed a process for the separation of long chain amino acid and long chain dibasic acid, comprising: (1) cooling the hydrolysis solution to crystallize and separate alkali salt of long chain dibasic acid to provide an aqueous solvent solution; (2) distilling the aqueous solvent solution of step (1) to recover the solvent and to recover alkylamine; (3) cooling the residual solution of step (2) to precipitate and separate alkali salt of long chain amino acid to provide a mother liquor; (4) adding an acid to the mother liquor of step (3) to yield alkanoic acid; (5) adding an acid to an aqueous solution of the alkali salt of long chain dibasic acid of step (1) to obtain long chain dibasic acid; and (6) neutralizing the alkali salt of long chain amino acid of step (3) with an acid to obtain long chain amino acid.

A method for the extraction and isolation of the terpene and isoprenoid compounds from plant material, followed by a centrifugal force induced selective crystallization of isoprenoids resulting in a separation of terpene and isoprenoid fractions. This this method is suitable for the extraction of cannabinoids from Cannabis and the enrichment tetrahydrocannabinolic acid and reduction of tetrahydrocannabinol in an extract. The purity of tetrahydrocannabinolic acid resulting from centrifugal crystallization is such that dissolution and selective recrystallization of tetrahydrocannabinolic acid is possible resulting in >99.9% pure tetrahydrocannabinolic acid, w/w.

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 logging device and method for locating a watered zone in a horizontal well with high watercut problem by isotope labeling is provided. The method successively includes the following operations: a. solidifying an isotope used in an isotope releasing device into a water-soluble carrier; b. connecting the isotope releasing device with a tubing and setting them to a horizontal segment of the well; c. dissolving the water-soluble carriers in the water at the bottom of the well to release the isotope, wherein the releasing rate is proportional to the flow rate of the water; d. starting a lift-up pump and beginning a production logging; and e. continuously performing -ray energy-spectrum analysis on produced water on the ground, so as to locate the watered zone of the horizontal well by the detected species and characteristic content of the isotope, thereby reduces operation risk, saves platform occupying time and logging cost.

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.

The invention relates to a method for recovering an organic compound from a feed stream comprising the steps of extracting the organic compound into an organic solvent, thereby obtaining a mixture of the solvent and the organic compound; and simultaneously crystallizing the solvent and the organic compound by cooling the mixture; and separating the solid organic solvent and solid organic compound.