COPPER-MEDIATED N1-ARYLATION OF BENZOTRIAZOLES

Benzotriazoles are group of bicyclic heterocyclic compounds that contain three nitrogen atoms fused to a benzene ring. Along with their derivatives, they possess a wide range of properties. They are used in medical field, as they exhibit such properties as antibacterial,antiplasmoidal,antiprotozoal, antifungal and anti-inflammatory activities, among others. They are also used in various industries as herbicides, UV absorbers, deicing and antiicing agents and corrosion inhibitors, to list a few. Because of their wide range of applications, we designed a new two-step synthesis for the formation of N-1-aryl benzotriazoles. 1-Hydroxy-1H-benzotriazole N-oxides were synthesized using phenylboronic acid (PhB(OH)2), pyridine in CH2Cl2as the solvent. A wide range of aryl boronic acids showed good reactivity with 1-hydroxy-1H-benzotriazole as well as 6-chloro-1-hydroxy-1H-benzotriazole under established conditions and moderate to high yields of products were isolated. Obtained N-oxides were then deoxygenated using tetrahydroxydiboron (B2(OH)4) in MeCN, following previously established conditions. N-Oxides resulting from the reactions of 5,6-dichloro-1H­-hydroxybenzotriazole were difficult to purify and prone to degradation. To alleviate the problem, a two-step one-pot reaction was designed. After N-arylation was complete and without any further purification, the reduction step was performed using B2(OH)4in MeCN. The method proved beneficial for the reaction with phenylboronic acid, and no significant improvement was observed in others. A reaction using 2-methoxypyrimidine-4-boronic acid showed that using established conditions, compounds with potential biological activity can be synthesized

1000 Liver Transplantations at the Department of General, Transplant and Liver Surgery, Medical University of Warsaw - Analysis of Indications and Results

The aim of the study was to analyze indications and results of the first one thousand liver transplantations at Chair and Clinic of General, Transplantation and Liver Surgery, Medical University of Warsaw.Material and methods. Data from 1000 transplantations (944 patients) performed at Chair and Clinic of General, Transplantation and Liver Surgery between 1994 and 2011 were analyzed retrospectively. These included 943 first transplantations and 55 retransplantations and 2 re-retransplantations. Frequency of particular indications for first transplantation and retransplantations was established. Perioperative mortality was defined as death within 30 days after the transplantation. Kaplan-Meier survival analysis was used to estimate 5-year patient and graft survival.Results. The most common indications for first transplantation included: liver failure caused by hepatitis C infection (27.8%) and hepatitis B infection (18%) and alcoholic liver disease (17.7%). Early ( 6 months) retransplantations were dominated by hepatic artery thrombosis (54.3%) and recurrence of the underlying disease (45%). Perioperative mortality rate was 8.9% for first transplantations and 34.5% for retransplantations. Five-year patient and graft survival rate was 74.3% and 71%, respectively, after first transplantations and 54.7% and 52.9%, respectively, after retransplantations.Conclusions. Development of liver transplantation program provided more than 1000 transplantations and excellent long-term results. Liver failure caused by hepatitis C and B infections remains the most common cause of liver transplantation and structure of other indications is consistent with European data