Highly soluble cellulose nitrates from unconventional feedstocks

Celluloses isolated by the nitric-acid process from domestic unconventional feedstocks such as Miscanthus, oat hulls, and intermediate flax straw were used herein to produce cellulose nitrates (CNs) with a high solubility. For the synthesis of CNs, a commercial technique was employed that involves nitration of cellulose with mixed acid containing 14 wt.% water followed by high-temperature treatment of the nitration product in acidic, alkaline, and neutral environments. The obtained CNs are similar in physicochemical attributes: 12.04–12.26% mass fraction of nitrogen, 10–14 mPa·s viscosity, and 98% solubility in alcohol– ester mixture. FTIR spectra of CNs had absorption bands (2559–2557, 1646–1631, 1277–1271, 825–812, 747–744, 683–680 cm-1) typical of nitro group vibrations. 13C NMR spectra showed chemical shifts representative of 6-mononitrocellulose, 2,6-dinitrocellulose, 3,6-dinitrocellulose, and 2,3,6-trinitrocellulose. DSC revealed that the resultant CNs were highly chemically pure with an exothermic peak at 209–212°С. The CNs obtained from the said unconventional feedstocks were compared with a commercial, highviscosity, lacquer-grade Colloxylin derived from cotton cellulose, as well as with other commercial Colloxylins, to show that the experimental CNs meet the requirements for comercial grades. Thus, the CNs obtained from the unconventional feedstocks are promising candidates as the component of composite explosives.

Synthesis, Spectroscopy, Thermal Analysis, Electrochemistry and Superoxide Scavenging Activity of a New Bimetallic Copper(II) Complex

A new bimetallic copper(II) complex has been synthesized with ligand obtained by the condensation of salicylaldehyde and the amine derived from reduction of nitration product of benzil. The ligand was characterized by1H NMR and mass spectra, and the binuclear Copper(II) complex was characterized by vibrational and electronic spectra, EPR spectra, and magnetic moment measurement. Thermogravimetric analysis study and electrochemical study of the complex were also done. The complex was found to show superoxide dismutase activity.

SYNTHESIS OF 6-NITRO VERATRYL ALCOHOL AND 6-NITRO VERATRALDOXIM FROM VANILIN AS INTERMEDIATES FOR THE PREPARATION OF C-9154 ANTIBIOTIC DERVATIVES

The synthesis of 6-nitro veratryl alcohol and 6-nitro veratraldoxim from vanilin which was required as intermediates for the preparation of C-9154 antibiotic derivatives was carried out. C-9154 antibiotic is a sufficiently potent antibiotic, but so far this is produced only in low yields through microbiological processes. The reaction steps performed were (1) methylation of vanilin, (2) nitration of the methylation product, (3) reduction of the corresponding nitro compound and (4) reaction of the nitration product with HO-NH2.HCl. Methylation of vanilin was conducted using dimethylsulfate and NaOH at 60 oC for 2 hours. Nitration of the methylation product was performed in 2 methods, i.e. using neat HNO3 and using a mixture of HNO3 and H2SO4 both at 5 oC for 2 hours. Reduction of the nitration product was conducted using NaBH4 either at room temperature and at reflux. Reaction of the nitration product with HO-NH2.HCl was carried out in ethanol 95% at 50 oC for 2 hours. The products were analyzed by means of TLC, GC, IR, 1H NMR and GC-MS spectrometers. The methylation of vanilin gave 87.7% yield of veratraldehyde which was found as a white crystal (m.p 43 oC). The nitration of veratraldehyde produced 6-nitro veratraldehyde observed as a yellow crystal having of m.p. 130 oC. Nitration using neat HNO3 gave a smaller yield (50.35%) of 6-nitro veratraldehyde than nitration with a mixture of HNO3 and H2SO4 (93.63%). Reduction of 6-nitro veratraldehyde using NaBH4 at room temperature and at reflux afforded 6-nitro veratryl alcohol which was found as brown crystal (m.p 123-127 oC) respectively in 13.47% and 56.61%. This reduction also produced 6-amino veratryl alcohol and 3,4-dimethoxy benzoic zcid as by products. 6-Nitro veratraldehyde reacts with HO-NH2.HCl to give 6-nitro veratraldoxim in 48.27% yield. Keywords: antibiotics, veratril alcohol, veratraldoxim vanilin

Medium-sized cyclophanes, part 59:1 Nitration of [3.3]- and [3.3.3]metacyclophanes — Through-space electronic interactions between two or three benzene rings

The two tert-butyl groups of anti-6,15-di-tert-butyl-9,18-dimethoxy[3.3]metacyclophane (anti-4) are both ipso-nitrated even under mild reaction conditions such as copper(II) nitrate in an acetic anhydride solution because of the decreased deactivation of the second aromatic ring by the introduced nitro group. On the other hand, anti-5,13-di-tert-butyl-8,16-dimethoxy[2.2]metacyclophane (anti-1) undergoes replacement of only one tert-butyl group under the same reaction conditions. The higher yields of the twofold ipso-nitration product anti-7 were obtained in nitration of anti-4 with fuming nitric acid or mixed acid (HNO3–H2SO4). Thus, the number of ipso-nitrations at the tert-butyl groups of anti-4 was strongly affected by the reactivity of the nitration reagent. Nitration of the corresponding syn-conformer syn-4 with copper(II) nitrate in an acetic anhydride solution, however, led only to the recovery of the starting compound. The presently developed procedure was further applied to the direct removal of the tert-butyl group by electrophilic substitution of the larger-sized ring macrocyclic metacyclophanes, cone- and partial-cone-tri-tert-butyl[3.3.3]metacyclophanes 11.Key words: [3n]metacyclophanes, conformation, ipso-nitration, through-space electronic interaction, crystal structure.