L-Alanine → N-Tosyl-L-alanine

Participants

Reaction Conditions

Reaction Steps

L-alanine (100 g; 1.11 moles) was dissolved in 2.25 L of 1N sodium hydroxide (aq), cooled to 5° C. and stirred while a solution of p-toluenesulfonyl chloride (218 g; 1.11 moles) in 450 mL of toluene was added slowly. The mixture was stirred at ambient temperature for 20 hr. The layers were separated and the chilled aqueous layer acidified to pH 1 with concentrated hydrochloric acid. The white solid title compound was collected by filtration, washed with water and dried. Yield 178.5 g (66%) mp 134°-5° C. IR (CHCl3) cm-1 1726, 1340, 1165, 1095; 1H NMR (DMSO-D6) δ 1.20 (d, J=7, 3H), 2.40 (s, 3H), 3.85 (p, J=8, 1H), 6.4 (br d, 1H)(CO2H), 7.41 (d, JAB =8, 2H) and 7.75 (d, JAB =8, 2H) [center of pattern: 7.58; ΔVAB =20.49 Hz], 8.03 (br d, J=8, 1H)(NH).

Provenance & Evidence