Examples CH3CH(CH2)sCH3 SOCl2 CHCH(CHa)sCH3 K2C03 OH Cl (81%) (pyridine often used instead of K2CO3) PBr3 (CH3)2CHCH2OH (CH3)2CHCH2Br (55-60%)
CH3CH(CH2 )5CH3 OH SOCl2 K2CO3 CH3CH(CH2 )5CH3 Cl (81%) (pyridine often used instead of K2CO3 ) (CH3 )2CHCH2OH (55-60%) (CH3 )2CHCH2Br PBr3 Examples
Preparation of Alkyl Halides (CH3)3COH HCI 25°C(CH3)3CCI1+H20 78-88% 80-100°C OH HBr Br+H2O 73% 120°C CH3(CH2)5CH2OH HBr CH3(CH2)5CH2Br H20 87-90%
Preparation of Alkyl Halides (CH3)3COH + HCl (CH3 )3CCl + H2O 78-88% + H2O 73% CH3 (CH2 )5CH2OH + HBr CH3 (CH2 )5CH2Br + H2O 87-90% 25°C 80-100°C 120°C OH + HBr Br
Preparation of Alkyl Halides A mixture of sodium bromide and sulfuric acid may be used in place of HBr. NaBr H2S04 CH3CH2CH2CH2OH CH3CH2CH2CH2Br heat 70-83% 120°C CH3(CH2)5CH2OH HBr CH3(CH2)5CH2Br H2O 87-90%
Preparation of Alkyl Halides CH3CH2CH2CH2OH CH3CH2CH2CH2Br NaBr H2SO4 70-83% heat A mixture of sodium bromide and sulfuric acid may be used in place of HBr. CH3 (CH2 )5CH2OH + HBr CH3 (CH2 )5CH2Br + H2O 87-90% 120°C
4.Diazonium coupling (for aryl halide only) Formation of a diazonium salt conc.HNO3 NO2 HCI/Sn conc.H,SO NH2 HNO> (or HCI+NaNO2) N'三N (diazonium salt) <5℃ NH2 HNO2 (or HCI NaNO2) >5℃
conc. HNO3 conc. H2 SO4 NO2 HCl / Sn NH2 NH2 HNO2 (or HCl + NaNO2 ) < 5 Co N N + (diazonium salt) NH2 HNO2 (or HCl + NaNO2 ) > 5 Co OH 4. Diazonium coupling (for aryl halide only) Formation of a diazonium salt
4.Diazonium coupling -Cont. From diazonium salt,you can make the following arylhalide N三N conc.HCI CuCl2 N三N conc.HBr B Cu,Br2 N2 N三N K1 N2
◼4. Diazonium coupling – Cont. N + N Cl + N2 conc. HCl Cu2 Cl 2 N + N N + N Br + N2 conc. HBr Cu2 Br 2 I + N2 KI / I From diazonium salt, you can make the following aryl halide