Sodium azide (3.58 g, 55.0 mmol) was added to DMSO (120 mL) and stirred
vigorously until fully dissolved. Benzyl bromide 168 (6.54 mL, 55 mmol)
was added. The reaction mixture was stirred at RT overnight. The
colourless liquid was worked up with water (100 mL), and extracted with
diethyl ether (3 x 100 mL). The extractions were washed with water (2 x
80 mL) and brine (80 mL). The ether layer was dried over MgSO4 and after
filtration, it was evaporated to dryness, giving benzyl azide 73 as a
colourless oil (6.9 g, 51.8 mmol, 94%): IR (neat) νm a x / cm– 1 3455, 3028,
2970, 2946, 2093, 1605, 1586, 1496, 1454, 1349, 1252; 1H NMR (400 MHz,
CDCl 3 ) δ 7.44 – 7.28 (m, 5H), 4.33 (s, 2H); 1 3C NMR (100 MHz, CDCl 3 ) δ
135.55, 129.05, 128.52, 128.44, 55.00.
