Diisopropyl Ether → HCID 12099060, compound

Following the general procedure, 4,5,6,7-tetrahydrobenzofuran-7-ylamine (150 mg, 1.09 mmol), CALB (45 mg), EtOAc (0.43 mL) and iPr2O (4.0 mL) were stirred for 17 hours. The conversion determined from 1H NMR by integration of the peaks at 5.09 ppm (CHNHAc) and 3.95 ppm (CHNH2) was 55%. Flash chromatography of the material on silica gel using 1:20 MeOH:CH2Cl2 followed by 1:1:4 NH4OH:MeOH:CH2Cl2 furnished (R)-N-(4,5,6,7-tetrahydrobenzofuran-7-yl)acetamide ((104 mg, 53%) in 79% ee (chiral GC method: 120° C. for 15 min, ramp rate of 2° C./min to 160° C., hold 20 min at 160° C., (S)-(−)-enantiomerrt=43.6 min, (R)-(+)-enantiomerrt=45.8 min); [α]D=+58° (c 1.04, CHCl3); 1H NMR (CDCl3, 300 MHz) δ 1.65-1.86 (m, 3H), 1.90-1.2.04 (m, 1H), 1.94 (s, 3H), 2.30-2.50 (m, 2H), 5.09 (br s, 1H), 6.16 (s, 1H), 7.24 (s, 1H); 13C NMR (CDCl3) δ 20.6, 22.4, 23.6, 31.0, 43.6, 110.7, 120.9, 142.2, 148.8, 170.1; MS m/z: 180 (M+H+). The unreacted (S)-4,5,6,7-tetrahydrobenzofuran-7-ylamine (was isolated in 39% yield (59 mg) and 94% ee (chiral GC, (S)-enantiomerrt=12.6 min, (R)-enantiomerrt=13.5 min); [α]D=−18° (c 0.59, CHCl3); 1H NMR (CDCl3, 300 MHz): δ 1.50-1.75 (m, 4H), 1.76-1.90 (m, 1H), 2.01-2.20 (m, 1H), 2.30-2.50 (m, 2H), 3.94 (t, 1H, J=5.7 Hz), 6.17 (d, 1H, J=1.5 Hz), 7.26 (d, 1H, J=1.5 Hz); 13C NMR (CDCl3): δ 21.1, 22.6, 34.0, 45.5, 110.5, 117.9, 141.3, 153.6; MS m/z: 160 (M+Na+).

ORD record

ord-a0e2cc98cad7453c970d927517d1b73a

Source dataset

uspto-grants-2008_11

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07452994B2