Haloalkanes & Haloarenes Flashcards
PCl₅ + Red P + Cl₂
ROH→R-Cl + POCl₃ + HCl
Mg + Dry ether
Prep. of GR
R-X + Mg → R-MgX
aq. NaOH, 368K / H₃O⁺
C₆H₃Cl(NO₂)₂ + NaOH (aq) → C₆H₃(OH)(NO₂)₂ (o,p - dinitro)
hν
Halogenation - attacks only alkane part
(Replacement Factor Rule)
R(CO)X + anhyd. AlX₃
FC Acylation
Cu + Dry ether
Ulman rxn
2 C₆H₅-X + 2 Cu → C₆H₅-C₆H₅ + 2 CuX₂
SbF₃ / HF / AgF / Δ
Swartz rxn
R-X + AgF/Δ → R-F + AgX
HBr + ROOR’
Anti - Markovnikov
LDA (Lithium diisopropyl amine)
(CH₃)₃CO⁻
Elimination (E₂)
Hofmann product is Major
HCl + CuCl₂ / Δ
Raschig process
C₆H₆ + HCl + CuCl₂ / Δ → C₆H₅Cl
H₂O/ Warm
C₆H₂Cl(NO₂)₃ + NaOH (aq) → C₆H₂(OH)(NO₂)₃ (Picric Acid)
R’-OH
RX →R-O-R’
NaNO₂ + HCl
Diazotization
C₆H₅NH₂ + HNO₂ + HCl → C₆H₅N₂⁺Cl⁻ + 2 H₂O
aq. NaOH, 443K / H₃O⁺
NO₂-C₆H₄-Cl→ NO₂-C₆H₄-OH (p-nitrophenol)
NH₃
RX →R-NH₂
FeX₃ + X₂
or Fe + X₂
Halogenation
C₆H₆ + X₂ + FeX₃ → C₆H₅X + HX + FeX₂
Poly Halo Compounds
Preparation and Properties of
Dihalo
Trihalo
Tetrahalo
alc. KOH
alc. NaOH
NH₂⁻
EtO⁻Na⁺ (Sodium ethoxide)
E₂ – Polar aprotic, Strong base
E₁ – Polar protic, Strong base in high temp.
E₁cb – If F is the leaving group (fluoroalkane)
E₁,E₂ - Saytzeff is major
E₁cb - hofmann is major
Cl₂ / H₂O (HOCl)
Br₂ / H₂O (HOBr)
Cl-I
Markovnikov of -OH (i.e O is more EN than Cl)
Markovnikov of -OH (i.e O is more EN than Br)
Markovnikov of -Cl (i.e Cl is more EN than I)
I₂ / HNO₃
C₆H₆→ C₆H₅I
(HNO₃ increase reactivity towards substitution of I⁻)
H₂SO₄ + SO₃
(Fuming sulphuric acid/oleum - H₂S₂O₇)
Sulphonation
NaOH + X₂
Haloform test
R-CO-CH₃ + X₂ + NaOH → R-COONa + CHX₃ (ppt.)
(X₂ = I₂ –> Iodoform test in presence of Keto methyl group
CHI₃ - yellow ppt.)
Sn + HCl
Reduction
C₆H₅NO₂ + Sn/HCl → C₆H₅NH₂
CuCN
C₆H₅Cl → C₆H₅CN
NaNO₂ / KNO₂
RX → R-ONO (Nitrite)
NaCN / KCN
RX →RCN
HBF₄ / Δ
Balz Schiemann rxn
C₆H₅N₂X → C₆H₅F
Red P / X₂ / Δ
In Situ Process
R-OH → RX
AgNO₂
RX→R-NO₂
NaI + Dry acetone
Finkelstein rxn
R-x + NaI → R-I + Nax
conc. H₂SO₄+ conc. HNO₃
Nitration
CCl₄
R(CO)OAg + Br₂ → RBr
Hunsdiecker rxn
NCS
NBS
Allylic substitution
R-CH=CH-CH₃ + X₂ → R-CH=CH-CH₂-X
NBS - Allylic substitution & Benzylic substitution
Chloral + 2 Chlorobenzene
DDT
Cl₂ / 500°C
Allylic substitution
R-CH=CH-CH₃ + X₂ → R-CH=CH-CH₂-X
H₂S
RX →R-SH (Thiol)
H₂O
RX→R-OH
RX + anhd. AlX₃
FC Alkylation
anhdyd. ZnCl₂ + HCl
Lucas test
RCH₂OH + HCl + ZnCl₂ → RCH₂Cl + H₂O
Note:
3° Alchol do not need anhdyd. ZnCl₂
only 1° and 2° needs anhdyd. ZnCl₂
Na + Dry ether
Wurtz
(2 R-X + 2 Na → R-R + 2 NaX)
Fittig
(2 C₆H₅X + 2 Na → C₆H₅-C₆H₅ + 2 NaX)
Wurtz - Fittig
(R-X + C₆H₅-X + 2 Na → R- C₆H₅ + 2 NaX)
SO₂Cl₂ + hν / ROOR’
Allylic substitution
R-CH=CH-CH₃ + X₂ → R-CH=CH-CH₂-X
PCl₃ + Red P + Cl₂
ROH → R-Cl + H₃PO₃
KI
Sandmeyer’s rxn
C₆H₅N₂⁺Cl⁻→ C₆H₅I
AgCN
RX →RNC
Cu₂O + NH₃ / 200°C / 60 atm
C₆H₅Cl → C₆H₅NH₂
HBr
Markovnikov
SOCl₂
R-OH + SOCl₂ →R-Cl + HCl + SO₂
(Darzens process)
note:
1.SOCl₂ - Retention pdt.
2. SOCl₂ + Base (e.g. - Py) - Inversion pdt.
Cu / HCl
Cu / HBr
C₆H₅N₂⁺Cl⁻ + Cu + HX → C₆H₅X + N₂
X = Cl, Br
Cu₂Cl₂ / HCl
Cu₂Br₂ / HCl
Sandmeyer’s rxn
(BDC –> Halobenzene)
C₆H₅N₂⁺Cl⁻ + Cu₂X₂ + HX → C₆H₅X + N₂ + CuX
X = Cl, Br
R’ -C≡C-Na
RX→R-C≡C-R’
preparation of R’C≡C-Na by NaNH₂ in NH₃
aq. NaOH / 623K / 300 atm
Dows Process (Benzyne mechanism)
C₆H₅Cl + NaOH → C₆H₅O⁻Na⁺ + H₃O⁺→C₆H₅OH
Cl₂ / CCl₄ (dark)
Anti - Addition
Zn/HCl
PS : ZnCl₂ + HCl - lucas reagent
CHCl₃ + Zn/HCl → CH₂Cl₂
CH₂Cl₂ + Zn/HCl → CH₃Cl
CH₃Cl + Zn/HCl → CH₄
Note:
1.C₆H₅CH₃ + Zn/HCl → C₆H₅CCl₃
2. -CCl₃ is a m-directing group
HNO₃ + CHCl₃
HNO₃ + CHCl₃ → CCl₃NO₂ (Chloropicrin)
