Question

14. Phentermine is mine is one component of the banned diet drug fee phen NH2 phentermine a. Label the amine as 1º,2º. or 3 b. Indicate the molecular shape around each atom. c. Draw a constitutional isomer that contains a lº amine. d. Draw a constitutional isomer that contains a 2º amine. e. Draw the structure of phentermine hydrobromide. f. What products are formed when phentermine is treated with benzoic acid, CH.COOH

Answer 1

a. It is identified as primary amine because there is presence of only one C--N bond.

All the C-atoms in the benzene ring are sp2 hybridised and thus have a treigonal planar shape. (1) The cratom here is sp3 hybridised and has a tetreahedreal shape and hence pushes the (2) C-atom out of plane. (2), (3), (4) C-atoms are also sp3 hybridised and have a tetrahedreal shape The N-atom is also sp²-hybridised but it is pyramidal in shape due to the presence of a lone paire of electrons over n-atom.

co Constitutional isomer of a l amine CH₂ - CH₂ - CH2-CH₂-NH₂ Butan-l-amine (primary) CH-CH-CH₂-NH2 2-Methylpropan-1-amine (Preimany)

d. Constitutional isomere of a 2 amine GHS C Hs-N-H N-Ethylethanamine (20) CH₂ Cha-N-H N-Methylpropan-1-amine (2)