590-42-1Relevant articles and documents
Tetrabutylammonium Iodide/I2 Mediated Convenient and Green Synthesis of Substituted Organic Isothiocyanates
Srivastava, Nitin
, p. 562 - 570 (2021/10/07)
-
A more sustainable isothiocyanate synthesis by amine catalyzed sulfurization of isocyanides with elemental sulfur
Nickisch,Conen,Gabrielsen,Meier
, p. 3134 - 3142 (2021/01/28)
Isothiocyanates (ITCs) are typically prepared using amines and highly toxic reagents such as thiophosgene, its derivatives, or CS2. In this work, an investigation of a multicomponent reaction (MCR) using isocyanides, elemental sulfur and amines revealed that isocyanides can be converted to isothiocyanates using sulfur and catalytic amounts of amine bases, especially DBU (down to 2 mol%). This new catalytic reaction was optimized in terms of sustainability, especially considering benign solvents such as Cyrene or γ-butyrolactone (GBL) under moderate heating (40 °C). Purification by column chromatography was further optimized to generate less waste by maintaining high purity of the product. Thus, E-factors as low as 0.989 were achieved and the versatility of this straightforward procedure was shown by converting 20 different isocyanides under catalytic conditions, while obtaining moderate to high yields (34-95%). This journal is
Preparation method of buprofezin
-
Paragraph 0024; 0026; 0027, (2018/10/11)
The invention provides a preparation method of buprofezin, comprising the steps of 1), adding sodium thiocyanate and water into an esterification kettle until dissolution; adding tertiary butanol andhydrochloric acid to obtain a mixed ester; allowing transposition and catalytic reaction to obtain t-butyl isothiocyanate; 2), adding the t-butyl isothiocyanate into chlorobenzene, stirring, dropwiseadding isopropyl amine to obtain 1-isopropyl-3-tert-butylthiourea solution; 3), adding N-methylaniline into chlorobenzene; introducing carbonyl chloride and chlorine gas in sequence to obtain N-chloromethyl-N-benzenecarbamoylchloride solution; 4), adding sodium bicarbonate into water, and adding the resultant into chlorobenzene; adding the 1-isopropyl-3-tert-butylthiourea solution; dropwise addingthe N-chloromethyl-N-benzenecarbamoylchloride solution, filtering, allowing layering, performing high-vacuum steaming to remove the chlorobenzene, crystallizing, centrifuging, and drying to obtain buprofezin. The substitutive average yield of the preparation process of buprofezin reaches 90% and above; the content of finished buprofezin reaches 98.0% and above; the preparation process is free ofammonia nitrogen wastewater.
