Fluorine-containing Drugs And Materials:Synthesis Of Florfenicol And Photochromic Materials

The introduction of fluorine into organic structures has significant impact on their properties in the field of medicines,agrochemicals and organic materials.In this thesis,research on the introduction and function of fluorine was carried out.The C-F bond construction of florfenicol was accomplished.Meanwhile,the introduction of fluorine to photochromic materials,and structure-property relationship was investigated.In the first part,this paper designed sulfuryl fluoride(SO2F2)as a fluorinating reagent,intended to directly convert thiamphenicol to florfenicol.It was found that the conversion can be achieved by a four-step reaction of "cyclization-ring conversion-fluorination-hydrolysis".After many attempts,sequence this conversion was achieved in a one-pot method with an overall yield of 12%.In the second part,fluorinated photochromic organic compounds were studied.8 new structures,3 monofluorinated and 3 multifluorinated,were prepared and compared against a commercially available reference product.The synthetic route involves a common ketone intermediate,a trifluoromethylation step using Rupert-Prakash reagent,a nucleophilic addition of carbonyl with an organometallic reagent,and DAST fluorination.The resulting sample was then formulated into a solution for further test rate of color-changing and fading,maximum absorption wavelength ?max in the visible region,and fading half-life was found that the functionalization at the target site affected the fading rate of the material through both spatial and electronic effects.Among them,the fluorine-containing functional group has a significant impact on the fading property of the material.Thus,the properties of the material can be adjusted by introducing a fluorine atom into the material.It is also found that some materials have superior fading performance at low temperatures,opening the possibility to discover low temperature photochromic material.In addition,the synthesis of three non-fluorinated naphthopyrans was completed.