Aromatic primary amines cannot be prepared by Gabriel Phthalimide synthesis.
Gabriel Phthalimide synthesis involves the reaction of phthalimide with an alkyl halide to form an amine. This method works well for aliphatic amines but fails for aromatic primary amines because the reaction does not readily occur with aryl halides. Aromatic rings are generally less reactive in nucleophilic substitution reactions due to the resonance stabilization of the ring, which makes it harder for the nucleophile (amide ion) to attack. Hence, Gabriel€™s synthesis does not work efficiently for preparing aromatic primary amines.


Study the given below single strand of deoxyribonucleic acid depicted in the form of a “stick” diagram with 5′ – 3′ end directionality, sugars as vertical lines and bases as single letter abbreviations and answer the questions that follow.
Name the covalent bonds depicted as (a) and (b) in the form of slanting lines in the diagram.
How many purines are present in the given “stick” diagram?
Draw the chemical structure of the given polynucleotide chain of DNA.
A circular coil of diameter 15 mm having 300 turns is placed in a magnetic field of 30 mT such that the plane of the coil is perpendicular to the direction of the magnetic field. The magnetic field is reduced uniformly to zero in 20 ms and again increased uniformly to 30 mT in 40 ms. If the EMFs induced in the two time intervals are \( e_1 \) and \( e_2 \) respectively, then the value of \( e_1 / e_2 \) is: