Sulfuric Acid → 2,4,4-trimethyl-5,6-dihydro-1,3(4H)oxazine

Participants

Reaction Conditions

Reaction Steps

Acetonitrile (22.6 g, 0.25 mol) was dripped into concentrated H2SO4 (150 mL) at 0° C. Upon complete addition of acetonitrile, 3-methyl-butane-1,3-diol (Fluka, 22.6 g, 0.55 mol) was added over 0.5 h maintaining the reaction temperature at or below 5° C. The resulting mixture was stirred for 1.5 h at 5° C. then poured onto crushed ice. When the ice had melted, the aqueous was extracted with ether (2×250 mL). The organic was discarded and the aqueous was treated with 40% NaOH to pH 12. The basic aqueous was extracted with ether. The organic was washed with brine and dried (MgSO4). The ether was removed under vacuum at 25° C. affording the desired product as a colorless oil (25.4 g, 50%): 1H NMR (DMSO-d6) δ 4.04 (t, 2H, J=6 Hz), 1.72 (s, 3H), 1.61 (t, 2H, J=6 Hz), 1.07 (s, 6H).

Provenance & Evidence