12th class chemistry chapter 6 haloalkane and haloarene 12th Board Darzens Reaction | Haloalkanes & Haloarenes | Class 12 Chemistry 🔬 Is video me hum Class 12 Chemistry – Haloalkanes & Haloarenes chapter ki important Name Reaction: Darzens Reaction ko simple language me samjhenge. Darzens reaction me aldehyde ya ketone ka reaction α-halo ester ke saath base ki presence me hota hai jisse glycidic ester (epoxide) banta hai. Ye reaction board exams, NEET aur JEE ke liye kaafi important hai. The Darzens Halogenation (Darzens Process) This reaction is a method used for the synthesis of chloroalkanes (alkyl chlorides) from primary and secondary alcohols. Reactants: Alcohol {ROH} and thionyl chloride{SOCl}_{2}Reagent: A nitrogen base, typically pyridine, is used.Products: Alkyl chloride {RCl}, along with sulfur dioxide {SO} and hydrogen chloride {HCl} gases. The synthesis of alkyl halide from alcohols via the treatment of thionyl chloride or bromide in the presence of small amounts of tertiary amines such as pyridine is generally referred to as Darzens halogenation. The halogen derivatives of phosphorus have been reported to cause isomerization, polymerization, and the Walden inversion of optically active alcohols. The alkyl halides are reported to form upon reflux in the presence of a large excess of thionyl halide and a small amount of pyridine. This reaction has general application in the conversion of alcohols into alkyl halides. Haloalkanes (alkyl halides) have halogens on sp³ carbons of open chains (e.g., \(CH_{3}Cl\)), while haloarenes (aryl halides) have halogens directly on sp² carbons of aromatic rings (e.g., \(C_{6}H_{5}Cl\)); the key difference is the carbon's hybridization and the resulting reactivity, with both being important organic compounds used as solvents, in medicine, and synthesis, derived from aliphatic and aromatic hydrocarbons, Haloalkanes (Alkyl Halides) Definition: Hydrogen atoms in an aliphatic (open-chain) hydrocarbon are replaced by halogens (F, Cl, Br, I).Structure: Halogen is attached to an \(sp^{3}\) hybridized carbon atom (e.g., methane \(\rightarrow \) chloromethane).Example: Chloromethane (\(CH_{3}Cl\)), bromoethane (\(CH_{3}CH_{2}Br\)). Haloarenes (Aryl Halides) Definition: Hydrogen atoms on an aromatic hydrocarbon (like benzene) are replaced by halogens.Structure: Halogen is directly attached to an \(sp^{2}\) hybridized carbon atom of the aromatic ring (e.g., benzene \(\rightarrow \) chlorobenzene).Example: Chlorobenzene (\(C_{6}H_{5}Cl\)), bromobenzene (\(C_{6}H_{5}Br\)). #DarzensReaction #HaloalkanesAndHaloarenes #Class12Chemistry #OrganicChemistry #NameReaction #BoardExam2026 #CBSEChemistry #NCERTChemistry #ChemistryShorts #ChemistryReels #ScienceWithFun #ChemistryConcepts #rbse #rbsechemistry subscribe for all 12th chemistry video