II.I.1. Quaternization reaction quaternization fluoropyridinehydrazone 1 with various alkyl halides 2-5 were successful carried out under The 4- both classical heating (CM) and ultrasound irradiations ))) and afforded the fluorinated pyridinium ionic liquids tagged Schiff base 6-9. F CH;CN R-X CM, )))) 1 2-5 6-9 R = -CH,COOEt, p-NO,C,H¾COCH,-, p-CIC,H¿COCH,-, C,H;O Scheme 1: Synthesis of ILs 6-9 through quaternization reaction. Conventional alkylation of compound 1 with various functionalized alkyl halides 2-5 in boiling acetonitrile for 24-48 hours afforded a series of functionalized ionic liquids iodide 6-9. When these reactions were carried out under ultrasound method, 4-5 h were required to give 6-9 in 85-95 %. The physical properties of the synthesized ILs were summarized in table 1. Table 1: Conventional versus ultrasound times and yields of ILs 108-111 tagged Schiff base Comp. No R Conventional Method Ultrasound Method СМ Time (h) Yield (%) Time (h) Yield (%) 6. CH,COOET 7 p-NO,C,H,COCH 24 | 85 | 5 | 88 p-CIC,H,COCH, 24 83 85 8 24 87 88 8. | C,H;O(CH,)4 48 86 4 88 II.I.2. Metathesis reaction The metathesis reaction of the synthesized ionic liquids 6-9 successfully by iodide exchange anion using some fluorinated metal salts such as sodium has been achieved potassium sodium tetrafluoroborate, hexafluorophosphate trifluoroacetate, in refluxing dichloromethane for 16 h, to afford new task specific ionic liquids 10- 12 in excellent yields (83-91 %) (Scheme 38). It has been noted that the use of ultrasound irradiation reduced dramatically the reaction times to 4-5 h to afford comparable yields (See table 2). and/or F F DCM + MY CM , ))) M= K, Na Y= PF6, BF4, COOCF3 CH;COOEt CH;COOE1 6 10-12 Scheme 3: Synthesis of ILs 10-12 tagged Schiff base Table 2: Conventional versus ultrasound times and yields of ILs 10- 123 Conventional Method Ultrasound Method Comp. No R Y СМ ))) Time (h) Yield (%)|Time (h) Yield (%) 10 PF6 CH,COOET 11 |CH,COOE1| BF, | 16 CH,COOE1 COOCF; 16 87 4 90 83 4 85 | 12 16 90 92

II.I.1. Quaternization reaction quaternization fluoropyridinehydrazone 1 with various alkyl halides 2-5 were successful carried out under The 4- both classical heating (CM) and ultrasound irradiations ))) and afforded the fluorinated pyridinium ionic liquids tagged Schiff base 6-9. F CH;CN R-X CM, )))) 1 2-5 6-9 R = -CH,COOEt, p-NO,C,H¾COCH,-, p-CIC,H¿COCH,-, C,H;O Scheme 1: Synthesis of ILs 6-9 through quaternization reaction. Conventional alkylation of compound 1 with various functionalized alkyl halides 2-5 in boiling acetonitrile for 24-48 hours afforded a series of functionalized ionic liquids iodide 6-9. When these reactions were carried out under ultrasound method, 4-5 h were required to give 6-9 in 85-95 %. The physical properties of the synthesized ILs were summarized in table 1. Table 1: Conventional versus ultrasound times and yields of ILs 108-111 tagged Schiff base Comp. No R Conventional Method Ultrasound Method СМ Time (h) Yield (%) Time (h) Yield (%) 6. CH,COOET 7 p-NO,C,H,COCH 24 | 85 | 5 | 88 p-CIC,H,COCH, 24 83 85 8 24 87 88 8. | C,H;O(CH,)4 48 86 4 88 II.I.2. Metathesis reaction The metathesis reaction of the synthesized ionic liquids 6-9 successfully by iodide exchange anion using some fluorinated metal salts such as sodium has been achieved potassium sodium tetrafluoroborate, hexafluorophosphate trifluoroacetate, in refluxing dichloromethane for 16 h, to afford new task specific ionic liquids 10- 12 in excellent yields (83-91 %) (Scheme 38). It has been noted that the use of ultrasound irradiation reduced dramatically the reaction times to 4-5 h to afford comparable yields (See table 2). and/or F F DCM + MY CM , ))) M= K, Na Y= PF6, BF4, COOCF3 CH;COOEt CH;COOE1 6 10-12 Scheme 3: Synthesis of ILs 10-12 tagged Schiff base Table 2: Conventional versus ultrasound times and yields of ILs 10- 123 Conventional Method Ultrasound Method Comp. No R Y СМ ))) Time (h) Yield (%)|Time (h) Yield (%) 10 PF6 CH,COOET 11 |CH,COOE1| BF, | 16 CH,COOE1 COOCF; 16 87 4 90 83 4 85 | 12 16 90 92

Organic Chemistry: A Guided Inquiry

2nd Edition

ISBN:9780618974122

Author:Andrei Straumanis

Publisher:Andrei Straumanis

Chapter15: Radical Reactions

Section: Chapter Questions

Problem 11E

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