Synthesis of Tyrosinase Inhibitors: Designing Chalcones

Saint Mary’s College of California Summer Research 2009Results and DiscussionG. DiazTable 1: Synthesized and Successfully Isolated Chalcones (numbered by order of isolation)Substituted R’ 1acetophenoneused to maketargetchalconeSubstituted R 2benzaldehydeused to make target chalconeTarget chalconeand reaction #a: solvent freeb: standardPercent yieldMelting pointRecrystallization solventR 24-Cl 2-Cl 2-F2,4,6-OCH 3-H 1a67.5%100-104ºCEthanol1b58.2%111-113ºCEthanol3b48.98%45-47ºCEthanol4a54.0%63-70ºCEthanol26b90.81%78-81ºCEthanol4-OH4-Cl 4-F2-F2’-ClKey 22’,4’-Cl 21bBenzaldehyde21 36 45R’ 14’3’2’5’1’6’Acetophenone11a (24ºC)83.34%132-137ºCEthanol8a84.0%75-76ºCEthanol30b>100%38-41ºCEthyl Acetate20b48.4%224-227ºCAcetone11a (60ºC)59.84%135-138ºCEthanol4-Cl4-OH2-Cl90.68%109-113ºCAcetone25b78.70%70-84ºCAcetone23a45.08%197-199ºCEthanol6For Table 1, the chalcones are grouped in no particular order. Initially in planning the synthesis, an ortho and para trend wasused but due to the availability of many starting materials, the chalcones’ design was to have a variety of derivatives based on thestructures of one or two known inhibitors as mentioned in Figure 3. This table’s purpose is to show what has been synthesized andisolated thus far. Going into more detail of its structure and comparing substituents will be discussed once an assay is done.For Tables 1 through 3, any percent yield that is >100% indicates the necessity for further purification. If the percent yield is n/a%,the reaction procedure was focused more on the identity for any product outcome and percent yield was disregarded for thepurposes of experimentations.