${R}-{NH}_{2} \stackrel{{CHCl}_{3}}{\longrightarrow} {R}-\stackrel{\oplus}{{N}} \equiv \stackrel{\ominus}{{C}} \xrightarrow[({HCl})]{{H}_{3} {O}^{\oplus}} {R}-{NH}_{2}+{HCOOH}$
$1^{\circ}$ amine $_{(A)}$ $\quad\quad$Isonitrile $_{(B)}$ $\quad\quad(C)$
$(i)$ મિથાઇલએમાઈન $(ii)$ ફોસ્જિન
$(iii)$ ફોસ્ફિન $(iv)$ ડાયમિથાઇલએમાઈન