Question

Indicate if the given statements are TRUE or FALSE regarding Hell Volhard Zelinski reaction 1. The reaction involves nucleophilic acyl substitution as well as alpha substitution. II. Bra facilitates the formation of the acid bromide. III. Hell Volhard Zelinski can also be done using acetic acid as the catalyst. IV. Br2 acts as the electrophile in the a-bromination step.

Answer 1

are. The steps in HVZ Û Step 1 : Nucleophilic Acyl Substitution p Brz Brz + P Forge's PBr3 which + R CH2 -Br Br facilitate acid - Br Н Bromide formation + R-CH₂ PBrz Then Br act as nucleophile and substitution, as does acyl Shown below. Н BY ,CH2 -PBrz PB12 он .CH₂ Br R- Uzo acid Bromide

Then, Hydrolysis takes place Step (2) ; 2- Bromination Step .CH Br Br R-CH₂ 11 OH (keto) Tawtomerize(Eno1) Then double bond of enol does nucleophilic attack >Br- at Brz electrophile • Br (electrophile) Br Br Br CH R Br Br Product OH Br +H₂O R. R (HBr) But in presence of acetic acid. Different inwanted product will form.

Br r CH- + CH₃ COOH R- 1- -HBY Br CH3 R un wanted Anhydride product. Acetic acid can't be used. Hence Answer (1) Tove (70 false (9t's PB83). (1) True (11) false chlorination OH L. CH₃NH2 C1 (A) Soch Answer, CH3 'N H Step 1 = = (A) Soch Step 2 = (2) CH3NH₂. Step 3 = NONE + CH3 @t + CH₃NH2 HE C1 - CHAR CHCI NH Answer