The Synthesis Of Stable Isotope Labeled Rhodamine B And Other Contraband Pigments Internal Standards For Determination

In recent years, contraband pigments additives have raised serious problems, which not only do harm to human health, but also endanger the harmony of our society. This dissertation recently developed the stable isotope labeled pigments as internal standards, which can greatly improve the accuracy of the detection of Rhodamine B and other contraband pigments.The five isotope internal standards synthesized in this dissertation:Auramine O-D12, Butter yellow-D6, Acid Orange 7-D4, Rhodamine B-D4, Acid Orange 23-D4. In order to optimize the reaction conditions, scientific methods were used in the experiment. After the improvement of each step of experimental explorations, the total synthesis was conducted. Then, the isotopically labeled experimtent was explored, and the products were characterized with high performance liquid chromatography, mass spectrometry, nuclear magnetic resonance spectroscopy, infrared radiation.1. The synthesis 4,4’-Methylenebis(N,N-dimethylaniline) optimum conditions:the molar ratio of n (N, N-dimethylaniline):n (formaldehyde solution) is 1:0.75, reaction time 4h, catalyst equivalent 5.0 mol% to obtain 4,4’-Methylenebis(N,N-dimethylaniline)-D12 with yield of 95.3%(base on N, N-dimethylaniline-D6). Its chemical purity is 98.0%, and isotopic enrichment is 98.0%(atom D)2. The synthesis Butter Yellow-D6 optimum conditions:the molar ratio of n (N, N-dimethylaniline):n (nitrite) is 1:1.2, reaction time 1h, with 0℃.The yield of butter yellow-D6 can reach to 78.2%(base on N,N-dimethylaniline-D6). Its chemical purity is 98.0%, and isotopic enrichment is 98.0%(atom D)3. We discovered an efficient synthesis of stable isotope labeled Acid Orange 7-D4 from sulfanilic acid-D4 as the precursor, hesis of stable isotope labeled acid orange 23-D4 with sulfanilic acid-D4 as the precursor. We applied the reaction of aniline with sulfanilic acid-D4 from diazotization and diazocoupling to synthesize the acid orange 7-D4.The yield of Acid orange 7-D4 can reach to 55.2%(base on sulfanilic acid-D4). Its chemical purity is 98.0%, and isotopic enrichment is 98.1%(atom D)4. This dissertation presented an efficient synthesis of stable isotope labeled Acid Orange 23-D4 with sulfanilic acid-D4 as the precursor. We applied the reaction of aniline with sulfanilic acid-D4 from diazotization and diazocoupling to synthesize the acid orange 23-D4.The yield of Acid orange 7-D4 was 43.2% as sulfanilic acid-D4 consumed. Its chemical purity is 98.1%, and isotopic enrichment is 98.1%(atom D)5. The synthesis Rhodamine B-D4 optimum conditions:the molar ratio of n (pathalic acid):n (3-diethylaminophenol) is 1:1.4, reaction time 4h,175℃ with yield 65.2%(base on pathalic acid-D4). Its chemical purity is 98.5%, and isotopic enrichment is 98.7%(atom D).