narak-wolhard-zelinsky halogenation

hell-wolhard-zelinsky helogenation pratikriya ack rasayanik parivartan haye jisamen α carbon parr carboxylic acid kaa helogenation shamil haye. iss pratikriya key liye α carbon koo cumm seey cumm ack proton honah chaahiye. iss pratikriya kaa naam german rasaayanagya carle magnus wonn hell (1849-1926) aur jacob wolhard (1834-1910) aur russie rasaayanagya nikole zelinsky (1861-1953) key naam parr rakhaa gayaa haye.
narak-kathor-zelinsky pratikriya kaa ack udaaharan propionic acid seey elenin kii taiyari mein dekhaa jaa sakata haye. pahale charan mein, bromin aur phosphorus tribromide (utprerak) key sanyojan kaa upayog 2-bromopropenic acid taiyar karane key liye narak-bhaari-zelinsky pratikriya mein kiya jaataa haye, jise dusare charan mein ammonolysis dwara amino acid utpaad key resemic mishran mein parivartit kiya jaataa haye.
tantra.
pratikriya kii shuruat utprerak matra mein pee. bee. aar. 3 koo jodkar kii jaati haye, jisake baad bee. aar. 2 key barabar ack daadh milaaya jaataa haye.
pee. bee. aar. 3 carboxylic oh koo bromide seey badal detaa haye, jisake parinamswarup carboxylic acid bromide hotaa haye. asyl bromide ack inol mein parivartit hoe jaataa haye, joe α sthiti mein bromin key liye bee. aar. 2 key saath pratikriya kartaa haye.
tatasth seey thodaa amleeya jaleey ghol mein, α-bromo asyl bromide kaa jall apghatan anayas hotaa haye, jisase nucleophilic asyl pratisthaapan key ack udaaharan mein α-bromo carboxylic acid praapt hotaa haye. yadi ack jaleey ghol vaanchhaniya haye, tou utprerak shrinkhala baadhit honey key kaaran pee. bee. aar. 3 key poorna daadh samatulya kaa upayog kiya jaanaa chaahiye.
yadi thodaa nucleophilic vilaayak maujood haye, tou carboxylic acid key saath α-bromo asyl bromide kii pratikriya seey α-bromo carboxylic acid praapt hotaa haye aur asyl bromide madhyavarti koo punarjeevit kartaa haye. vyavhaar mein pee. bee. aar. 3 key daadh samatulya kaa upayog aksar dheemi pratikriya gativigyaan koo door karane key liye kiya jaataa haye.
ack alcanoel bromide aur ack carboxylic acid key beach vinimay key liye tantra neeche diyaa gayaa haye.
dou bromides key electron-nikasi prabhaavon key kaaran α-bromoalcanoil bromide mein ack majboot electrophilic carbonyl carbon hotaa haye.
paani key bajaay alcohol key saath pratikriya koo bujhaa curr, α-bromo ester praapt kiya jaa sakata haye.

