This invention discloses a type of 1,8-bis(Schiff base)-p-menthane derivatives as well as their preparation method and applications. The reaction of 1,8-diamino-p-menthane with a substituted benzaldehyde was carried out in a polar organic solvent at 0 C.-75 C. for 1-48 h. After the completion of the reaction, part of the solvent was distilled off to perform recrystallization to get a 1,8-bis(Schiff base)-p-menthane derivative, whose pre-emergence herbicidal activity against ryegrass was determined by using the Petri dish seed germination method. The 1,8-bis(Schiff base)-p-menthane derivatives, obtained with this method in high yield and mild reaction conditions, have a good inhibitory effect on the growth of annual ryegrass, and low toxicity.

This invention discloses a type of 1,8-bis(Schiff base)-p-menthane derivatives as well as their preparation method and applications. The reaction of 1,8-diamino-p-menthane with a substituted benzaldehyde was carried out in a polar organic solvent at 0 C.-75 C. for 1-48 h. After the completion of the reaction, part of the solvent was distilled off to perform recrystallization to get a 1,8-bis(Schiff base)-p-menthane derivative, whose pre-emergence herbicidal activity against ryegrass was determined by using the Petri dish seed germination method. The 1,8-bis(Schiff base)-p-menthane derivatives, obtained with this method in high yield and mild reaction conditions, have a good inhibitory effect on the growth of annual ryegrass, and low toxicity.

The invention relates to the chemical synthesis of pharmaceutical API, and specifically to a method of synthesizing diclofenac sodium, which is a kind of nonsteroidal anti-inflammatory drug for relieving pain. The method includes: nitrating phenylacetate to prepare o-nitrophenylacetate (2); hydrogenating o-nitrophenylacetate (2) to prepare o-aminophenylacetate (3); amidating an amino group of o-aminophenylacetate (3) to obtain 2-(2-benzoylaminophenyl) acetate (4); 2-(2-benzoylaminophenyl) acetate (4) reacting with thionyl chloride to prepare a chloroimine intermediate, and then condensing the intermediate of chloroimine with 2,6-dichlorophenol using an inorganic base to prepare (E)-methyl-2-(2-((2,6-dichlorophenoxy)(phenyl)methyleneamino) phenyl ester (5); subjecting (E)-methyl-2-(2-((2,6-dichlorophenoxy)(phenyl)methyleneamino) phenyl ester (5) to Chapman rearrangement to afford methyl 2-(2-(N-(2,6-dichlorophenyl)benzoylamino)phenyl) ester (6); and hydrolyzing methyl 2-(2-(N-(2,6-dichlorophenyl)benzoylamino)phenyl) ester (6) to provide the target compound as of diclofenac sodium API. The overall yield is up to 67% based on methyl phenylacetate.

The invention relates to the chemical synthesis of pharmaceutical API, and specifically to a method of synthesizing diclofenac sodium, which is a kind of nonsteroidal anti-inflammatory drug for relieving pain. The method includes: nitrating phenylacetate to prepare o-nitrophenylacetate (2); hydrogenating o-nitrophenylacetate (2) to prepare o-aminophenylacetate (3); amidating an amino group of o-aminophenylacetate (3) to obtain 2-(2-benzoylaminophenyl) acetate (4); 2-(2-benzoylaminophenyl) acetate (4) reacting with thionyl chloride to prepare a chloroimine intermediate, and then condensing the intermediate of chloroimine with 2,6-dichlorophenol using an inorganic base to prepare (E)-methyl-2-(2-((2,6-dichlorophenoxy)(phenyl)methyleneamino) phenyl ester (5); subjecting (E)-methyl-2-(2-((2,6-dichlorophenoxy)(phenyl)methyleneamino) phenyl ester (5) to Chapman rearrangement to afford methyl 2-(2-(N-(2,6-dichlorophenyl)benzoylamino)phenyl) ester (6); and hydrolyzing methyl 2-(2-(N-(2,6-dichlorophenyl)benzoylamino)phenyl) ester (6) to provide the target compound as of diclofenac sodium API. The overall yield is up to 67% based on methyl phenylacetate.

Provided herein are cinchonium betaine catalysts and methods of promoting asymmetric imine isomerization reactions using the same.

Provided herein are cinchonium betaine catalysts and methods of promoting asymmetric imine isomerization reactions using the same.

The invention discloses a method for preparation of protected difluoromethylornithine by a difluoromethylation of dibenzaldimine ornithine ester using CHF.sub.3 and LiHMDS (lithium bis(trimethylsilyl)amide), which can be converted to a salt of unprotected difluoromethylornithine by a subsequent deprotection under acidic conditions in the presence of water.

The invention discloses a method for preparation of protected difluoromethylornithine by a difluoromethylation of dibenzaldimine ornithine ester using CHF.sub.3 and LiHMDS (lithium bis(trimethylsilyl)amide), which can be converted to a salt of unprotected difluoromethylornithine by a subsequent deprotection under acidic conditions in the presence of water.

A polyaldimine of the formula (I) with advantageous properties in use as latent hardener for compositions including isocyanate groups, and compositions containing the polyaldimine of the formula (I) and at least one polyisocyanate and/or at least one polyurethane polymer containing isocyanate groups. The polyaldimine of the formula (I) is odourless, pH-neutral, liquid at room temperature, has low viscosity, has little sensitivity to heat and moisture, and is stable in storage together with isocyanates. It can provide odourless single-component polyurethane compositions which have good stability in storage and which do not produce bubbles when hardened in the presence of moisture, and which cause no problematic odour emissions, giving a hardened elastic material with good mechanical properties and surprisingly little tendency towards plasticizer migration.

A polyaldimine of the formula (I) with advantageous properties in use as latent hardener for compositions including isocyanate groups, and compositions containing the polyaldimine of the formula (I) and at least one polyisocyanate and/or at least one polyurethane polymer containing isocyanate groups. The polyaldimine of the formula (I) is odourless, pH-neutral, liquid at room temperature, has low viscosity, has little sensitivity to heat and moisture, and is stable in storage together with isocyanates. It can provide odourless single-component polyurethane compositions which have good stability in storage and which do not produce bubbles when hardened in the presence of moisture, and which cause no problematic odour emissions, giving a hardened elastic material with good mechanical properties and surprisingly little tendency towards plasticizer migration.