Methods of preparing a polyaspartic ester composition comprise reacting a primary diamine reactant composition with a diester reactant composition under conditions to prepare a polyaspartic ester composition having a primary amine value of less than 35 mg KOH/g wherein, at the time of the reaction, the combined water content of the primary diamine reactant composition and the diester reactant composition is less than 300 ppm. Compositions and methods of use of the compositions are also described.

Disclosed are a pH-responsive amphoteric surfactant N-lauryl-(-alkyl)--aminopropionic acid and a preparation method and uses thereof. An alkylamine and a solvent are added to a three-necked flask, stirred for complete dissolution, slowly dropwise added with methyl -alkyl-acrylate and reacted at room temperature after the ice-water bath is removed. The reaction mixture is refluxed in water bath and evaporated under rotation to remove the solvent and the residual methyl -alkyl-acrylateto give N-lauryl-(-alkyl)--aminopropionic acid. Then N-lauryl-(-alkyl)--aminopropionic acid and water are added to a three-necked flask, slowly dropwise added with a sodium hydroxide solution and reacted in water bath to give a crude product, which is filtered and dried to give a purified surfactant sodium N-lauryl-(-alkyl)--aminopropionate. This surfactant is suitable for the foamed acid system and its performance can be switched by adjusting pH due to pH sensitivity.

Disclosed are a pH-responsive amphoteric surfactant N-lauryl-(-alkyl)--aminopropionic acid and a preparation method and uses thereof. An alkylamine and a solvent are added to a three-necked flask, stirred for complete dissolution, slowly dropwise added with methyl -alkyl-acrylate and reacted at room temperature after the ice-water bath is removed. The reaction mixture is refluxed in water bath and evaporated under rotation to remove the solvent and the residual methyl -alkyl-acrylateto give N-lauryl-(-alkyl)--aminopropionic acid. Then N-lauryl-(-alkyl)--aminopropionic acid and water are added to a three-necked flask, slowly dropwise added with a sodium hydroxide solution and reacted in water bath to give a crude product, which is filtered and dried to give a purified surfactant sodium N-lauryl-(-alkyl)--aminopropionate. This surfactant is suitable for the foamed acid system and its performance can be switched by adjusting pH due to pH sensitivity.

In one aspect, the present disclosure provides methods of preparing a primary or secondary amine and hydroxylated aromatic compounds. In some embodiments, the aromatic compound may be unsubstituted, substituted, or contain one or more heteroatoms within the rings of the aromatic compound. The methods described herein may be carried out without the need for transition metal catalysts or harsh reaction conditions.

In one aspect, the present disclosure provides methods of preparing a primary or secondary amine and hydroxylated aromatic compounds. In some embodiments, the aromatic compound may be unsubstituted, substituted, or contain one or more heteroatoms within the rings of the aromatic compound. The methods described herein may be carried out without the need for transition metal catalysts or harsh reaction conditions.

In one aspect, the present disclosure provides methods of preparing a primary or secondary amine and hydroxylated aromatic compounds. In some embodiments, the aromatic compound may be unsubstituted, substituted, or contain one or more heteroatoms within the rings of the aromatic compound. The methods described herein may be carried out without the need for transition metal catalysts or harsh reaction conditions.

The invention relates to a new enantioselective process for producing useful intermediates for the manufacture of NEP inhibitors or prodrugs thereof, in particular NEP inhibitors comprising a -amino--biphenyl--methylalkanoic acid, or acid ester, backbone.

The invention relates to a new enantioselective process for producing useful intermediates for the manufacture of NEP inhibitors or prodrugs thereof, in particular NEP inhibitors comprising a -amino--biphenyl--methylalkanoic acid, or acid ester, backbone.

The invention relates to a new enantioselective process for producing useful intermediates for the manufacture of NEP inhibitors or prodrugs thereof, in particular NEP inhibitors comprising a -amino--biphenyl--methylalkanoic acid, or acid ester, backbone.

The invention relates to a method for preparing 6-aminocaproic acid (hereinafter also referred to as 6-ACA) using a biocatalyst. The invention further relates to a method for preparing E-caprolactam (hereafter referred to as caprolactam) by cyclising such 6-ACA. The invention further relates to a host cell, a micro-organism, or a polynucleotide which may be used in the preparation of 6-ACA or caprolactam.