In the 1800s, hospitals were often dangerous places. Many doctors didn't wear caps and gowns or wash their hands before they began to work. Doctors also hadn't discovered how to put people to sleep so a patient was usually awake during an operation. Some people died from the pain, but more often, they died from an infection, when germs got into their wounds. Back then, people believed that an infection was caused by something in the air.  

Joseph Lister

“Father Of Modern Surgery"

The hospital environment has not always been a place of sterility and extreme cleanliness that is associated with it so readily today.  Prior to the work of Joseph Lister, the hospital was a place to go to die, not to be cured.  If an individual was able to survive the pain and torture of surgery without anesthesia, a postoperative infection would most certainly be their ultimate demise.  Thanks to Joseph Lister, a hospital is now a place of healing and cleanliness, not one of death and filth.

Doctor Joseph Lister spent many years trying to find out how to prevent infection. In 1869, Dr. Lister invented a pump to spray carbolic acid into the air in operating theaters. It wasn't very pleasant to work with, but the chemical killed the bugs and kept patients safer. Soon, other hospitals began to use carbolic acid and more and more people survived their operations. Joseph Lister, bug buster, had made an important discovery that saved many lives.

Carbolic Acid is produced when phenol reacts with water…………….

+ H2O

OH O ─

+ H3O

+

Modern surgeons

Antiseptics

OH

CH3C

l

3HC

OH

OH

(CH2)5CH3

4 – chloro – 3,5 – dimethylphenol4 - hexylresorcinol

Because of Joseph Lister’s contribution to science, specifically in the field of medicine….The first company that produces health care and hygiene products was name after him to

give him recognition for his works.

PHENOL

What is phenol ?

OH

An “alcohol – like” compounds that have the hydroxyl group bound to a benzene ring.

Phenol is derived from the old name for benzene (phene), to include the suffix that indicates it possesses a hydroxyl group (ol).

CAUTION: The word phenol (C6H5-OH) is often confused with phenyl (C6H5-). Phenols are acidic and are important intermediates in the preparation of aryl ethers, C6H5-OR .

Phenol may be found as a translucent, clear, or light-pink crystalline mass; a white powder, or a clear liquid. It has a sweet, sharp odor or medicinal odor. Addition of small amount of water causes the solid to liquefy at room temperature. Phenol is used in many commercially available products including plastics, resins, fertilizers, paints, photographic developers, and some medicines.

NAME Melting point Boiling PointSolubility

g/100ml at 25°C

Phenol 41°C 182°C 11.3g

Methanol ─ 97°C 65°C Any amount

Description: Phenol is both a manufactured chemical and a natural substance. It is a colorless-to-white solid when pure. The commercial product is a liquid. Phenol has a distinct odor that is sickeningly sweet and tarry. You can taste and smell phenol at levels lower than those that are associated with harmful effects. Phenol evaporates more slowly than water, and a moderate amount can form a solution with water.Warning properties: pungent odor is usually adequate to warn of acute exposure ingestion can be fatal. Flammability: nonflammable

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Natural Phenols

Cloves

OH

OCH3

CH2 – CH ═ CH2

EUGENOL / Cloves

Nutmeg

OHOCH3

CH ═ CH – CH3

ISOEUGENOL/NUTMEG

Aniseed

OCH3

CH ═ CH – CH3

ANETHOLE

Vanilla

OHOCH3

H – C ═ OVANILLIN

Thyme

OH

CH – CH3

CH3

3HC

THYMOL / THYME MINT

Wintergreen

C – O – CH3

O

OH

METHYL SALICYLATE

Synthetic Phenol Derivatives

OH C

CH3

CH3

CH3

OCH3

Butylated Hydroxy Anisole(BHA

)2 – t – butyl – 4 - methoxyphenol

OH CC

CH3

CH3

CH3

CH3

CH3

CH3

3HC

Butylated Hydroxy Toluene

(BHT)2,6 – di – t – butyl – 4 - methylphenol

Disinfectant

C – OH

O

OH

Salicylic Acid

OH

O - phenylphenol

CH2OH

Cl2 – benzyl – 4 - chlorophenol

Beverage preservative

Food preservative

Additive for coal tar/ asphalt modification

Dyes, Pigments & Colorants

Rubber & Plastic

Antioxidant

Aromatic Rules When a single hydrogen of the benzene ring is replaced by a

hydroxyl, the compound can be named as a derivative of benzene or simply PHENOL.

A number of phenol derivatives are known by common names that are also IUPAC – accepted and are used preferentially over other possibilities.

Compounds formed by replacing a hydrogen of benzene with more complex hydrocarbon group can be named by designating the benzene ring as substituent.

We called them phenyl group. When two groups are attached to a benzene ring, three isomeric

structures are possible. They can be designated by the prefixes ortho (o), meta (m), and para (p):

When two or more groups are attached to a benzene ring, their positions can be indicated by numbering the carbon atoms of the ring so as to obtain the lowest possible numbers for the attachment positions.

Group that comes first in alphabetical order is given the lower number.

OH

CH3

CH3

3HC

OH

CH3CH2

2ON

NO2

HO

C6H5

C6H5

C6H5

OH

Br

Cl

2,3,4 - triphenylphenol

2 – ethyl – 4,5 - dinitrophenol

3 – bromo – 5 – chlorophenol

3,4,5 - trimethylphenol

OH

OHOH

OH

OH

OH

OH

Phenol Cathecol

Resorcinol

Hydroquinone

OH

CH3

P – methylphenol

OH

OH

Br

Cl2 – bromo – 5 – chlorohydroquino

ne

OH

OHCH3CH2 5 – ethylresorcin

ol

OH

HO

NO2

2ON

3,5 - dinitrocathecol

Phenol Reactions

HalogenationNitrationSulfonationAkylationEther Formation

Halogenation

OH

+ Br2

U r ask 2 produce 2,4,6 - tribromophenol O

H Br

+ HBr

Then……… all u have 2 do is to continue the sequence of reaction 2 produce ur

desired product.

FeBr3

NitrationU r ask 2 produce m - nitrophenol

OH

+ HNO3

+ H2O

OH

NO2

20°CH2SO4

Sulfonation

+ SO3

H2So4

15 – 20 °C

OH OH SO3H

O – phenolsulfonic acid

TEMPERATURE VARY DEPENDING ON THE DESIRED POSITION.

100 °C FOR PARA POSITION

Alkylation

+ CH3 – C – CH3

CH3

Cl

OH

HNO3

C

CH3

CH3

CH3

OH

+ HCl

2 – t – butylphenol / O – t – butylphenol

IN THIS REACTION U WILL BE USING AN ACID CATALYST IT CAN BE HNO3, HF, HI, OR HCl.

Williamson synthesis/Ether

formation

OH

+ CH3 – CH2 – Br

NaOH

Δ

O CH2CH3

+ HBr

ethoxybenzene

Time 4 ur much

awaited Exercise…………