AZT: Azidodeoxythymidine: Drug that treats human immunodeficiency virus (HIV):

AZT, the abbreviation for azidodeoxythymidine, is a drug that treats human immunodeficiency virus (HIV), the virus that causes acquired immune defi ciency syndrome (AIDS). Also known by its generic name zidovudine, AZT represents a chemical success to a different challenge:

Amoxicillin:

Fluoxetin:Antidepressant:

Fluoxetine: Antidepressant:

Fluoxetine is a oral capsule its the generic name for the antidepressant Prozac and Prozac Weekly. Prozac was designed and synthesized by chemists in the laboratory, and is now produced on a large scale in chemical factories.  In some cases, they may not be available in every strength or form as brand-name drugs. . For the treatment of depressive episodes related to bipolar I disorder and treatment-resistant depression, this drug must be used with olanzapine

Amoxicillin:

DDT:Dichlorodiphenyltrichloroethane:

Amoxicillin:Antibiotics:

Amoxicillin is one of the most widely used antibiotics in the penicillin family. The discovery and synthesis of such antibiotics in the twentieth century have made routine the treatment of infections that were formerly fatal. You were likely given some amoxicillin to treat an ear infection when you were a child.

DDT(dichlorodiphenyltrichloroethane):

DDT- DichloroDiphenylTrichloroethane:

DDT, the abbreviation for dichlorodiphenyltrichloroethane, is a colorless, tasteless, and almost odorless crystalline chemical compound, an organochlorine.  DDT use as pesticide and also called “miraculous” by Winston Churchill because of the many lives it saved by killing disease carrying mosquitoes.

DDT was first synthesized in 1874 by the Austrian chemist Othmar Zeidler. DDT's insecticidal action was discovered by the Swiss chemist Paul Hermann Müller in 1939. DDT was used in the second half of World War II to control malaria and typhus among civilians and troops. DDT use is now banned in the United States and many developed countries because it is a nonspecific insecticide that persists in the environment

Reactivity order of Pyrrole, Furan and Thiophene towards Electrophilic substitution :

Pyrrole, furan and thiophene undergo electrophilic substitution reactions like nitration, sulphonation, halogenation etc. characteristic of aromatic rings. That carbons in 5-membered heterocyclic rings have higher electron density compared to benzene and hence undergo electrophilic substitution more readily than benzene.The electrophilic substitution takes place preferentially at 2-position (C-2).

The attack of an electrophile on pyrrole, for example, will lead to formation of 2- and 3-substitution products by way of carbocations (1) and (2) respectively.The substitution occurs preferably at C-2 position because the intermediate obtained by attack at this position is more stable than the intermediate obtained by attack at C-3. The positive charge in intermediate (1) is more delocalized than intermediate (2) and hence is more stable and preferred intermediate.

The electrophilic substitution at C-2 in furan and thiophene can also be accounted in the same manner. Furan is not as reactive as pyrrole in electrophilic substitution reactions because the oxygen in furan is more electronegative than nitrogen in pyrrole and therefore does not enhance the electron density of carbons as much as pyrrole. Thiophene is less reactive than furan towards electrophilic substitution because the p-electrons of sulphur are in 3p orbital which overlaps less effectively than the 2p orbital of nitrogen or oxygen with 2p orbitals of carbon. The relative reactivities towards electrophilic substitution follows the order:

Bredt's rule:

SIR effect:
Dancing Resonance:
Inversion of Amines: