An Improved N-Acylation of 1H-Benzotriazole Using 2,2′-Dipyridyl­di­sulfide and Triphenylphosphine

A novel path has been developed for the conversion of carboxylic acids into the corresponding N-acylbenzotriazoles by using 2,2′-dipyridyl disulfide/PPh3 in anhydrous dichloromethane in the presence of 1H-benzotriazole. Mild reaction conditions, short reaction time, easy in handling, wide substrate scope, availability of reagents involved, and moreover avoiding the use of base makes this protocol quite useful for the laboratory practices for N-acylbenzotriazole synthesis.

Synthesis and X-ray diffraction data of 5-acryloyloxy-trans-2-(4-methoxyphenyl)-3-methyl-2,3-dihydrobenzo[b]furan

The compound O-acryloylated 2,3-dihydrobenzo[b]furan-5-ol (2) described in the title (chemical formula C19H18O4) was synthesized through the acryloylation reaction in anhydrous dichloromethane from the corresponding trans-2-(4-methoxyphenyl)-3-methyl-2,3-dihydrobenzo[b]furan-5-ol derivative (1), an adduct easily obtained using the Lewis acid-promoted formal [3 + 2] cycloaddition reaction. Molecular characterization was performed by Fourier Transform-Infrared (FT-IR), Gas Chromatography-Mass Spectrometry (GC-MS), 1H and 13C NMR and crystallographic characterization was carried out by X-ray diffraction (XRD) of polycrystalline samples. The title compound crystallized in a monoclinic system and unit-cell parameters are reported [a = 8.067(2) Å, b = 8.803(2) Å, c = 22.405(5) Å, β = 91.62(3)°, unit-cell volume V = 1590.7(6) Å3 and Z = 4]. All measured lines were indexed with the P21/c (No. 14) space group.

Synthesis of Poly L-Glutamate Initiated by Triethanolamine

With L-glutamic acid as raw materials, N-carboxy-L-glutamic acid-benzyl-anhydride (BLG-NCA) was synthesized by triethanolamine. With triethanolamine as the initiator in the anhydrous dichloromethane, ring-opening polymerization of BLG-NCA was initiated, poly-l-glutamic acid benzyl ester was obtained. The amount of initiators, molar ratio of monomer/initiators, reaction temperature and reaction time to the effect of poly-l-glutamic acid benzyl ester in the ring-opening polymerization of BLG-NCA were studied. At last, poly L-glutamate was got, after the debenzylation in HBr solution. Through infrared spectroscopy, Ubbelohde viscometer, 1H NMR spectra, polymerization product was characterized and analysized. Results showed that in dichloromethane, ring-opening polymerization of BLG-NCA could be initiated by triethanolamine.

Study of Synthesis and Properties on Poly L-Glutamate Initiated by Aniline

With L-glutamic acid as raw materials, N-carboxy-L-glutamic acid-benzyl-anhydride (BLG-NCA) was synthesized by triphosgene. With aniline as the initiator in the anhydrous dichloromethane, ring-opening polymerization of BLG-NCA was initiated, poly-l-glutamic acid benzyl ester was obtained. The amount of initiators, Molar ratio of monomer/initiators, reaction temperature and reaction time to the effect of poly-l-glutamic acid benzyl ester in the ring-opening polymerization of BLG-NCA were studied. Through infrared spectroscopy, gel permeation chromatography (GPC) analysis and characteristic viscosity method, polymerization product was characterized and analysized. Results showed that in dichloromethane, ring-opening polymerization of BLG-NCA could be initiated by aniline, which expands greater scope of the initiators of poly-l-glutamate to aromatic compounds, and the introduction of the active group provided by aromatic compounds make it possible for the advanced development of block copolymer with poly-l-glutamic acid as a basic unit.