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Journal of Chemistry
Volume 2016, Article ID 9734108, 6 pages
Research Article

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

1College of Chemical Engineering, Nanjing Tech University, Nanjing 210009, China
2Department of Environmental Sciences, Macquarie University, Sydney, NSW 2109, Australia

Received 16 June 2016; Accepted 28 July 2016

Academic Editor: Albert Demonceau

Copyright © 2016 Feng Xue et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Supplementary Material

Supporting Information Synthesis of 4-Methoxyphenyl 7β-t-butyl-carbonylamino-3-chloromethyl- 3-cephem-4-carboxylate (4a): 20.25 g (0.05 mol) p-Methoxybenzyl 7β-amino-3-chloromethyl-3-cephem4- carboxylate hydrochloride (5a, ACLE.HCl) was dissolved into 200 mL dichloromethane in a flask with mechanical stirring under ice cooling at 0-5°C.Then 10.2 g (0.10 mol) triethylamine was introduced into the mixture to neutralize the pH at 7-8 for 15 min before adding 10 g SiO2 and 13.1 g (0.06 mol) Boc2O into the flask under ultrasonic bath at 0-5°C. The reaction lasted for 30 mins at room temperature. When the raw material (5a) completely disappeared and transformed as indicated by TLC, the mixture was poured into 500 mL water, following by washing with brine water for organic phase. Next, the organic phase was dried with anhydrous sodium sulfate and the solvent was evaporated by vacuum to produce the crude product (4a). Finally, the rude products were purified by column chromatography to obtain the pure white amorphous powders (2.27 g, yield 96.0%). HPLC assay confirmed the purity of 4a was 98.5%. The column oven temperature was set at 295 K. The mobile phase was consisted of methanol and deionized water (75:25, v/v) and flowed through the column in 15 min with the flow rate of 1.0 mL/min. Photodiode array detection was used to detect the Boc-ACLE (or Boc-ACLH)at the wavelength of 254 nm. 1H and 13C NMR refer to table 3 and 4 [1]. ESI-HRMS: calcd. for C21H24ClN2O6S ([M-H]-) 467.1049, found 467.1045.

Synthesis of Benzhydryl 7β-t-butoxycarbonylamino-3-chloromethyl-3-cephem- 4-carboxylate (4b): The 4b compound was prepared according to a similar manner to that of the 4a but using the 5b (ACLH.HCl) as raw material. The weight of purified product was 5.0 g (yield 96.2%). The purity of 4b was 98.1%. (The HPLC method was similar to the 4a). m.p.140-142°C (decomposed). 1H NMR refer to Table 5 [2]. 13C NMR (75 MHz,DMSO-d6): δ 170.86, 165.01, 161.06, 159.34, 135.70, 130.25, 28.93, 128.16, 126.84, 126.43, 125.29, 124.83, 113.77, 67.28, 59.18, 57.96, 57.86, 55.06, 43.72, 41.55, 40.33, 26.09. ESI-HRMS: calcd. for C26H27ClN2O5NaS ([M+Na]+) 537.1221, found 538.1243.

  1. Supplementary Material