Xiaoliu Li

Design, microwave-assisted synthesis and HIV-RT inhibitory activity of 2-(2,6-dihalophenyl)-3-(4,6-dimethyl-5-(un)substituted-pyrimidin-2-yl)thiazolidin-4-ones

A series of novel thiazolidin-4-ones bearing a hydrophobic substituent at 5-position on the 4,6-dimethyl-pyrimidine ring at N-3 (5c-i and 6c-i) were designed on the prediction of QSAR studies, synthesized in good yields of 60.1-85.3% by microwave-assisted one-pot protocol with the combination of using dicyclohexylcarbonimide (DCC) as the promotor, and evaluated as HIV-1 reverse transcriptases inhibitors. The results of in vitro HIV-1 RT kit assay showed that some of the new compounds, such as 5c, 6c, 5d, 6d, 5g, 5h and 6i, could effectively inhibit RT activity. Among them, compounds 5c and 6c where ethyl group existed at 5-position on N-3 pyrimidine ring were the best ones with the IC(50) value of 0.26 microM and 0.23 microM, respectively. Structure-activity relationship analysis of these analogues suggested that the overall hydrophobicity and steric factor were important to the anti-HIV RT activity. The mechanism of the intramolecular cycloamidation promoted by DCC was also investigated with the key uncyclized intermediate 13.

An Efficient One‐Pot Synthesis of 3,4‐Dihydropyrimidin‐2‐ones Catalyzed by Methanesulfonic Acid

Abstract An efficient synthesis of 3,4‐dihydropyrimidin‐2‐ones (DHPMs) from the aldehydes, β‐ketoesters, and urea in ethanol using methanesulfonic acid (CH3SO3H) as the catalyst is described. Compared with the classical Biginelli reaction conditions, this method has the advantage of excellent yields and short reaction time.

Direct and Convenient Method of Regioselective Benzylation of Methyl α‐D‐Glucopyranoside

Abstract A facile and convenient method for the direct preparation of methyl 2,3,6‐tri‐O‐benzyl‐α‐D‐glucopyranoside (2) by the regioselective benzylation of methyl α‐D‐glucopyranoside (1) with benzyl bromide in the presence of mild bases K2CO3 and KOH (1∶1) without solvents is reported.

Convenient, Microwave-Assisted, One-Pot Synthesis of Photochromic Fulgimides Bearing Reactive Groups

A convenient, microwave-assisted, one-pot synthesis of the fulgimides (3) bearing reactive groups on N-substituents from the corresponding fulgides (1a–d) and amines (2a–e) is described. The synthesis provided the functionalized fulgimides (3) in yields of 50–84% under microwave irradiation within 25 min in the presence of 4-dimethylaminopyridine (DMAP) and dicyclohexylcarbodiimide (DCC).

Uncertainty analysis on the magnetic system of joule balance

Based on the special structure of exciting coils system of joule balance, the uncertainty sources of the magnetic density in the geometrical center of magnetic field was analyzed and evaluated. The relative combined standard uncertainty of magnetic field in ΔH/H was 4.9 × 10-4. In addition, it was proved that the largest component of uncertainty was u(I), which was 2.8×10-4. Therefore the high-precision constant-current source was recommended to reduce uncertainty of magnetic field of joule balance.