Bromoethane is treated successively with (i) KCN in ethanol, (ii) dilute H2SO4 under reflux, (iii) Br2 with a little red phosphorus, then H2O, and (iv) excess NH3. The final organic product is

JEE Advanced levelSingle correct optionDifficulty 3 of 3co199

Bromoethane is treated successively with (i) $KCN$ in ethanol, (ii) dilute $H X_{2} SO X_{4}$ under reflux, (iii) $Br X_{2}$ with a little red phosphorus, then $H X_{2} O$ , and (iv) excess $NH X_{3}$ . The final organic product is

Step (i) gives

CH X_{3} CH X_{2} CN

(one carbon added), (ii) hydrolyses it to

CH X_{3} CH X_{2} COOH

, (iii) is the HVZ reaction giving

CH X_{3} CHBrCOOH

, and (iv) substitutes bromine by

NH X_{2}

. The product is 2-aminopropanoic acid (alanine).