Chapter 20, Problem 46P

Propose structures for compounds X, Y, and Z:

$X\left(C_7{H}_{7}Br\right)\underset{}{\overset{NaCN}{\to }}Y\left(C_8{H}_{7}N\right)\underset{}{\overset{LiAl{H}_4}{\to }}Z\left(C_8{H}_{11}N\right)$

The ${}^{1}H$ NMR spectrum of X gives two signals, a multiplet at $\delta$ 7.3 (5H) and a singlet at $\delta$ 4.25 (2H); the 680-840 $c{m}^{-1}$ region of the IR spectrum of X shows peaks at 690 and 770 $c{m}^{-1}$. The ${}^{1}H$ NMR spectrum of Y is similar to that of X: multiplet at $\delta$ 7.3 (5H), singlet at $\delta$ 3.7(2H). The ${}^{1}H$ NMR spectrum of Z is shown in Fig. 20.7.

FIGURE 20.7 The ${}^{1}H$ NMR spectrum of compound Z. Problem 20.46. Expansion of the signals is shown in the offset plot.