2-Amino-2-methyl-1-propanol → (2S,3S)-2-(3-chlorophenyl)-3-ethyl-5,5-dimethylmorpholin-2-ol

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Reaction Steps

Compound 4s was synthesized by a procedure similar to that described for (2S,3S)-4a using (R)-1-(3-chlorophenyl)-2-hydroxybutan-1-one (10j, 1.13 g, 0.0568 mol), Proton sponge (1.43 g, 0.0667 mol), triflic anhydride (1.0 g, 0.063 mol), and 2-amino-2-methyl-1-propanol (1.09 g, 0.0122 mol) in CH2Cl2 (13 mL). After purification, the free base 4r was converted to 0.230 g of its D-tartrate salt: mp 160-161° C.; [α]20D +5.6° (c 0.8, CH3OH); 1H NMR (methanol-d4) δ 7.49-7.46 (m, 1H), 7.41-7.35 (m, 3H), 4.37-4.34 (m, 1H), 4.30-4.24 (m, 1H), 3.81-3.62 (m, 2H), 1.57 (s, 3H), 1.47-1.36 (m, 2H), 1.33 (s, 3H), 0.81-0.71 (m, 3H); 13C NMR (methanol-d4) δ 178.5, 145.2, 135.6, 131.2, 130.3, 128.2, 126.5, 97.1, 75.0, 67.8, 61.1, 55.0; LCMS (ESI) m/z 270.4 [(M-tartrate)+, M=C16H23ClNO5); Anal. (C16H23ClNO5.0.25H2O) calcd: C, 55.01; H, 6.78; N, 4.01. found: C, 54.99; H, 6.85; N, 4.08.

Provenance & Evidence