A method for producing a carbamic acid salt, including contacting a carbon dioxide-containing mixed gas having a partial pressure of carbon dioxide of 0.001 atm or more and less than 1 atm with an amino group-containing organic compound in the presence of a base in at least one organic solvent selected from the group consisting of an organic solvent having 2 or more and 8 or less carbon atoms, and a method for producing a carbamic acid ester or a urea derivative using the carbamic acid salt.

Disclosed in the present invention are a low energy consumption anhydrous CO.sub.2 phase change absorption agent, and a regeneration method and an application thereof, the absorption agent using a unitary diamine with a primary amine (NH.sub.2—) and a tertiary amine (—N—), and not containing any other organic solvent, water, and ionic liquid; two alkyl branches are linked to a nitrogen atom of the tertiary amine, forming a certain hydrophobicity; after absorbing the CO.sub.2, the diamine changes from a liquid phase to a solid phase, undergoing liquid-solid phase change to form white amino formate crystals.

Disclosed in the present invention are a low energy consumption anhydrous CO.sub.2 phase change absorption agent, and a regeneration method and an application thereof, the absorption agent using a unitary diamine with a primary amine (NH.sub.2—) and a tertiary amine (—N—), and not containing any other organic solvent, water, and ionic liquid; two alkyl branches are linked to a nitrogen atom of the tertiary amine, forming a certain hydrophobicity; after absorbing the CO.sub.2, the diamine changes from a liquid phase to a solid phase, undergoing liquid-solid phase change to form white amino formate crystals.

Disclosed is a method for preparing salicylamine acetate. The method comprises the steps of: (1) carrying out amino protection on salicylaldehyde having a structure represented by formula 1 to obtain a compound having a structure represented by formula 2; and (2) carrying out acid hydrolysis to the compound having a structure represented by formula 2 and then reacting the acid-hydrolyzed compound with acetic acid to obtain salicylamine acetate.

Disclosed is a method for preparing salicylamine acetate. The method comprises the steps of: (1) carrying out amino protection on salicylaldehyde having a structure represented by formula 1 to obtain a compound having a structure represented by formula 2; and (2) carrying out acid hydrolysis to the compound having a structure represented by formula 2 and then reacting the acid-hydrolyzed compound with acetic acid to obtain salicylamine acetate.

The present invention provided a process for manufacture of amantadine nitrate derivatives, and the process comprises using adamantane as the raw material to prepare amantadine nitrate derivatives via the following steps: (1) synthesis of adamantanol; (2) carboxylation of adamantanol; (3) acetylation of adamantanoic acid; (4) reduction; (5) hydrolysis of amido adamantanol and Boc protection of amino group; (6) crystallization of Boc protected amantadinol; (7) nitrate esterification of Boc protected amantadinol; (8) refining of the product of nitrate esterification; (9) Boc deprotection and salt formation; and (10) refining of amantadine nitrate hydrochloride. The amantadine nitrate derivatives have the struction of:

##STR00001##

wherein, R.sub.1 and R.sub.2 are each independently hydrogen, straight-chain or branched-chain alkyl, or substituted or unsubstituted aryl or heteroaryl. The process of this invention is efficient, cost effective, environmentally friendly, safe, reliable, and suitable for industrial production.

The present invention provided a process for manufacture of amantadine nitrate derivatives, and the process comprises using adamantane as the raw material to prepare amantadine nitrate derivatives via the following steps: (1) synthesis of adamantanol; (2) carboxylation of adamantanol; (3) acetylation of adamantanoic acid; (4) reduction; (5) hydrolysis of amido adamantanol and Boc protection of amino group; (6) crystallization of Boc protected amantadinol; (7) nitrate esterification of Boc protected amantadinol; (8) refining of the product of nitrate esterification; (9) Boc deprotection and salt formation; and (10) refining of amantadine nitrate hydrochloride. The amantadine nitrate derivatives have the struction of:

##STR00001##

wherein, R.sub.1 and R.sub.2 are each independently hydrogen, straight-chain or branched-chain alkyl, or substituted or unsubstituted aryl or heteroaryl. The process of this invention is efficient, cost effective, environmentally friendly, safe, reliable, and suitable for industrial production.

The invention relates to a method for the preparation of a 4,5-dihydroxyisoleucine derivative comprising the steps of asymmetric Claisen rearrangement of a Z-aminocrotyl-glycin ester and subsequent kinetic resolution of the product diastereomer mix by acylase, and subsequent Sharpless dihydroxylation of the resulting 2-amino-3-methylpent-4-enoic acid derivative.

The invention relates to a method for the preparation of a 4,5-dihydroxyisoleucine derivative comprising the steps of asymmetric Claisen rearrangement of a Z-aminocrotyl-glycin ester and subsequent kinetic resolution of the product diastereomer mix by acylase, and subsequent Sharpless dihydroxylation of the resulting 2-amino-3-methylpent-4-enoic acid derivative.

The present invention relates to peptide modifier compounds of Formula (1), or a salt thereof, wherein: a is an integer from 1 to 10, more preferably from 1 to 3; b is an integer from 0 to 7; Z is a terminal group and Y is a bivalent group. Further aspects of the invention relate to intermediates in the preparation of compounds of Formula (1), and the use of compounds of Formula 1 in the synthesis of peptide derivatives. ##STR00001##