Appearance
White to Almost white powder to crystal
Detection Method
Octadecanedioic acid mono-tert-butyl ester (18-(tert-Butoxy)-18-oxooctadecanoic Acid) is a preparation raw material of the side chain of the somaglutide. The technical scheme is that a purchased raw material with the main component of octadecanedioic acid mono-tert-butyl ester is detected, whether the purity of the raw material substance is within a quality control standard or not is verified, and the purpose of detecting the purity of the raw material substance is to ensure the synthesis yield of a finished product of the side chain of the later-stage somnautide. For process reasons, raw materials usually comprise impurities such as octadecanedioic acid, tetradecanedioic acid mono-tert-butyl ester, hexadecanedioic acid mono-tert-butyl ester, octadecanedioic acid mono-methyl ester and octadecanedioic acid mono-methyl ester, and the current detection method mainly bases on the general rule of the four departments of the 2015 version of Chinese pharmacopoeia, but no method for separately detecting the octadecanedioic acid mono-tert-butyl ester exists, and the product is a long-chain alkane series, has long retention time in a chromatographic column and is difficult to elute in a proper time. A method for testing octadecane dioic acid mono-tert-butyl ester comprises the following steps: S1. preparing a test solution and a system suitability solution; S2. using high performance liquid chromatography for detection, the chromatographic conditions comprising: using Agilent ZORBAX SB-C18 as a chromatographic column, using 0.1% phosphoric acid aqueous solution as mobile phase A, using acetonitrile as mobile phase B, performing gradient elution, the column temperature being 35°C, the flow rate being 1.0 mL/min, and the detection wavelength being 210 nm; S3. calculating the purity of the test sample by the area normalization method, and observing the sizes of known impurities and other unknown impurities in the chromatogram.
Description
Octadecanedioic acid mono-tert-butyl ester is a non-cleavable ADC linker or alkyl chain-based PROTAC linker for the synthesis of antibody-drug couplings (ADCs) and PROTACs.
Uses
18-(tert-Butoxy)-18-oxooctadecanoic Acid is a synthetic intermediate used in the preparation of semaglutide. It can be produced by the catalysis of 18-hydroxyoctadecanoic acid by ethyl bromoacetate in the presence of formamide and magnetic trifluoroacetic acid.
Uses
18-(tert-Butoxy)-18-oxooctadecanoic Acid is used to engineer long-acting, potent exendin-4 based GLP-1 analog for microstructure-based transdermal delivery for glycemic control.
Application
18-(tert-Butoxy)-18-oxooctadecanoic acid) is a short linker featuring a carboxylic acid and a tert-butyl ester. Carboxylic acids can be reacted with alcohols or amines, while the tert-butyl ester can be deprotected and further connected to another molecule. It is a pharmaceutical intermediate ingredient used in the preparation of somatostatin. It also has catalytic activity.
Synthesis
A suspension of octadecanedioic Acid (15 g, 47.7 mmol) in Toluene (191 ml) was brought to reflux in 3 neck 1 L round bottom flask. When all the Acid was in solution, 1,1 -di-tert-butoxy-N, N-dimethylmethanamine (22.87 ml, 95 mmol) was added dropwise over 30 minutes. The reaction mixture was heated under reflux overnight. The reaction was stopped after 20 total hours of heating. The reaction mixture was cooled to room temperature, resulting in solid precipitation. The mixture was filtered by vacuum filtration. The resulting white solid was suspended in 200 ml dichloromethane and stirred for 15 minutes. The remaining solids were removed via vacuum filtration. The collected solids were again suspended in dichloromethane and stirred for 15 minutes. After a second filtration, the combined filtrates were concentrated in vacuo, and the resulting white powder 18-(tert-Butoxy)-18-oxooctadecanoic Acid was dried undervacuum.
