PAAL–KNORR FURAN SYNTHESIS
375
13C NMR (75 MHz, CDCl3): d ¼ 163.5, 159.8, 149.2, 148.8, 131.6, 129.8, 129.0,
122.0, 118.3, 115.9, 107.9, 60.4, 14.3, 13.9.
Compound 12c. Yellow crystals. Mp: 71–72ꢀC; 1H NMR (300 MHz,
CDCl3): d ¼ 8.43–7.47 (m, 4H), 6.69 (s, 1H), 6.11 (s, 1H), 2.39 (s, 3H); 13C NMR
(75 MHz, CDCl3): d ¼ 153.5, 149.8, 148.7, 132.6, 129.5, 128.6, 121.0, 117.9, 108.2,
13.7. HRMS (EI) calcd. for C11H9NO3 203.0582; found 203.0583.
Compound 14b. Yellow crystals. Mp: 174–175ꢀC; 1H NMR (300 MHz,
CDCl3): d ¼ 8.30–7.48 (m, 9H), 7.32 (s, 1H), 4.35 (q, 2H, J ¼ 7.1 Hz), 1.37 (t, 3H,
J ¼ 7.1 Hz); 13C NMR (75 MHz, CDCl3): d ¼ 162.9, 158.2, 149.8, 146.8, 135.3,
130.0, 129.0, 128.5, 128.2, 124.4, 124.1, 116.3, 111.8, 60.9, 14.2. HRMS (EI) calcd.
for C19H15NO5 337.095; found 337.0962.
Compound 16b. Yellow crystals. Mp: 128–129ꢀC; 1H NMR (300 MHz,
CDCl3): d ¼ 8.32–7.32 (m, 9H), 7.09 (s, 1H), 4.35 (q, 2H, J ¼ 7.1 Hz), 1.39 (t, 3H,
J ¼ 7.1 Hz); 13C NMR (75 MHz, CDCl3): d ¼ 162.9, 153.7, 152.9, 147.3, 135.2
128.9, 128.8, 128.7, 128.4, 124.1, 123.3, 118.6, 108.5, 61.1, 14.2. HRMS (EI) calcd.
for C19H15NO5 337.095; found 337.0953.
Compound 17b. Yellow crystals. Mp: 240–241ꢀC 1H NMR (300 MHz,
CDCl3): d ¼ 8.35–7.90 (m, 8H), 7.38 (s, 1H), 4.38 (q, 2H, J ¼ 7.1 Hz), 1.41 (t, 3H,
J ¼ 7.1 Hz); 13CNMR (75 MHz, CDCl3): d ¼ 162.5, 155.0, 151.4, 148.0, 147.4,
134.7, 129.1, 124.6, 123.6, 119.0, 112.1, 61.4, 14.2. HRMS (EI) calcd. for
C19H14N2O7 382.0801; found 382.0796.
Compound 18b. Yellow crystals. Mp: 177–178ꢀC; 1H NMR (300 MHz,
CDCl3): d ¼ 8.55–7.63 (m, 8H), 7.31 (s, 1H), 4.39 (q, 2H, J ¼ 7.1 Hz), 1.42 (t, 3H,
J ¼ 7.1 Hz); 13CNMR (75 MHz, CDCl3): d ¼ 162.5, 154.3, 151.2, 148.8, 147.8,
134.8, 130.6, 130.1, 129.6, 123.5, 123.0, 118.9, 110.7, 61.4, 14.2. HRMS (EI) calcd.
for C19H14N2O7 382.0801; found 382.0802.
Compound 18c. Yellow crystals. Mp: 158–159ꢀC; 1H NMR (300 MHz,
CDCl3): d ¼ 8.57–7.60 (m, 8H), 6.98 (s, 1H), 6.97 (s, 1H); 13C NMR (75 MHz,
CDCl3): d 152.8, 152.2, 148.8, 146.7, 135.6, 131.5, 130.0, 129.5, 124.4, 124.1,
122.5, 118.7, 111.3, 110.0. HRMS (EI) calcd. for C16H10N2O5 310.0590; found
310.0593.
1
Compound 19b. White crystals. H NMR (300 MHz, CDCl3): d ¼ 7.58–7.29
(m, 5H), 4.30 (q, 2H, J ¼ 7.1 Hz), 2.60 (s, 3H), 2.39 (s, 3H), 1.36 (t, 3H, J ¼ 7.1 Hz);
13C NMR (75 MHz, CDCl3): d 164.7, 158.3, 147.6, 130.9, 128.4, 127.1, 126.0, 116.8,
115.2, 59.8, 14.3, 10.8.
Compound 21b. 1H NMR (300 MHz, CDCl3): d ¼ 8.28–7.30 (m, 9H), 4.12
(q, 2H, J ¼ 7.1 Hz), 2.36 (s, 3H), 0.98 (t, 3H, J ¼ 7.1 Hz); 13C NMR (75 MHz,
CDCl3): d 164.3, 150.4, 147.0, 135.7, 132.2, 129.4, 128.1, 127.4, 123.9, 123.6,
117.8, 61.0, 13.5, 12.1. HRMS (EI) calcd. for C20H17NO5 351.1107; found 351.1105.
Compound 22c. 1H NMR (300 MHz, CDCl3): d ¼ 6.21 (1H, s), 4.26 (2H, q,
J ¼ 7.1 Hz), 2.52 (3H, s), 2.36 (3H, s), 1.33 (3H, t, J ¼ 7.1 Hz); 13C NMR (75 MHz,
CDCl3) d ¼ 164.4, 157.6, 150.0, 114.2, 106.3, 60.0, 14.5, 13.7, 13.2.