Research Article

Ultrasonic-Assisted Synthesis of Two t-Butoxycarbonylamino Cephalosporin Intermediates on SiO2

Table 5

Comparison of 1H NMR data (4b).

Dai et al. reported (500 MHz, CDCl3)Synthetic 4b (300 MHz, DMSO-d6)

1.49 (s, 9H)1.38 (s, 9H)
3.49, 3.57 (d, 2H, J = 14 Hz)3.52 (d, 1H, J = 1.38 Hz)
3.66 (d, 1H, J = 17.97 Hz)
4.98 (d, 1H, J = 4 Hz)5.12 (d, 1H, J = 4.14 Hz)
5.21 (d, 1H, J = 8 Hz)
5.65 (dd, 1H, J = 4, 8 Hz)5.56 (s, 1H)
6.98 (s, 1H)6.93 (s, 1H)
7.3–7. 5 (m, 10H)7.27–7.49 (, 10H)
7.38 (s, 1H)
8.01–8.04 (d, 1H, J = 8.49)

Data taken from [7]; this work.