40 results about "N acylation" patented technology

Provided herein are processes for the preparation of N-acylated amines. In particular, the processes comprise contacting an amine with an acid comprising a carboxylic acid group to form the N-acylated amine.

The present invention provides, as for a method for analyzing the C-terminal amino acid sequence of a peptide by using a reaction for successively releasing the C-terminal amino acids of the peptide, which method can suppress, when successively releasing the C-terminal amino acids of a peptide of long amino acid length, such a undesirable side reaction as cleavage of peptide bond in the intermediate position of the peptide and can carry out the chemical treatment thereof under widely applicable conditions, a following method wherein a dry sample of a peptide with long amino acid length is beforehand subjected to an N-acylation treatment; by using a reaction reagent where an alkanoic acid anhydride is combined with a small amount of a perfluoroalkanoic acid, successive release of C-terminal amino acids is conducted under mild conditions; a hydrolysis treatment is applied; then, selective fragmentization at site of arginine residue is performed by digestion by trypsin; thereafter, decreases in molecular weight are measured for the C-terminal side fragments derived from a series of reaction products by analysis in negative mode of a MALDI-TOF-MS apparatus; thereby, the C-terminal amino acid sequence of the peptide sample is identified.

The present invention provides a method for analyzing the C-terminal amino acid sequence of a peptide by using a reaction for successively releasing the C-terminal amino acids of the peptide, which method can suppress, when successively releasing the C-terminal amino acids of a peptide of long amino acid length, such a undesirable side reaction as cleavage of peptide bond in the intermediate position of the peptide and can carry out the chemical treatment thereof under widely applicable conditions; In the method, a dry sample of a peptide with long amino acid length is beforehand subjected to an N-acylation treatment; by using a reaction reagent where an alkanoic acid anhydride is combined with a small amount of a perfluoroalkanoic acid, successive release of C-terminal amino acids is conducted under mild conditions; a hydrolysis treatment is applied; then, selective fragmentization at site of arginine residue is performed by digestion by trypsin; thereafter, decreases in molecular weight are measured for the C-terminal side fragments derived from a series of reaction products with use of a MALDI-TOF-MS apparatus; thereby, the C-terminal amino acid sequence of the peptide sample is identified.

The invention belongs to the technical field of antibiotic drug synthesis, and particularly relates to a preparation method of cefotiam hydrochloride. The preparation method comprises the following steps of: adding formamido thiazole acetic acid to an organic solvent, adding base and dithio-bisbenzothiazole, stirring, then adding a catalyst, and carrying out condensation reaction, thus obtaining an active ester A, wherein the catalyst is triethyl phosphate; dissolving 7-ACMT in an alkali liquor of the organic solvent, adding the active ester A for carrying out N acylation reaction, adding a water solution after reaction is ended, getting a water layer, adding hydrochloric acid for hydrolysis, and dropwise adding a hydrophilic solvent to separate out the cefotiam hydrochloride. The preparation method has the advantages that reaction conditions are mild, strict anhydrous and anaerobic conditions are not needed, the cost is low, the synthesis process is simple, and the purity and the yield are high.

The present disclosure is related to an improved and efficient process for preparation of (3R,4R)-(1-benzyl-4-methylpiperidin-3-yl)-methylamine which comprises:(a) N-acylation of 3-Amino-4-methyl pyridine; (b) Quarternization of 3-Acetylamino-4-methyl pyridine using benzyl halide; (c) Partial reduction of quarternized 3-Acetylamino-4-methyl pyridine by Sodium borohydride in Methanol or water; (d) Hydrolysis of partially reduced product to 1-Benzyl-4-methylpiperidin-3-one in presence of acid; (e) Reductive amination of 1-Benzyl-4-methylpiperidin-3-one using Methanolic methylamine in presence of Titanium(IV) isopropoxide in Methanol; (f) Resolution of 1-Benzyl-4-methylpiperidin-3-yl)-methylamine using Ditoluoyl (L) tartaric acid to get (3R,4R)-(1-benzyl-4-methylpiperidin-3-yl)-methylamine. The disclosure is also related to novel intermediates:wherein R, R′ and X are as described in the specification.