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1.
ChemMedChem ; 13(19): 2053-2056, 2018 10 08.
Article in English | MEDLINE | ID: mdl-30070428

ABSTRACT

A more sustainable process for the synthesis of the long-acting muscarinic acetylcholine antagonist umeclidinium bromide is described. Specifically, we report the synthesis of ethyl 1-(2-chloroethyl)-4-piperidinecarboxylate, a key intermediate in the preparation of umeclidinium bromide, in good yields using triethylamine, as well as the identification and characterization of the by-product formed in this reaction. This new method of synthesis leads to an improvement in yield over that of previously reported protocols using potassium carbonate as base (65.6 % versus 38.6 %). Moreover, in the final synthetic step of the process to obtain umeclidinium bromide, we were able to replace the use of toxic solvents (acetonitrile/chloroform) with water. The use of this green solvent allowed precipitation of the active pharmaceutical ingredient (API) from the reaction medium with high purity and in high yield. Overall, we have developed a more efficient and environmentally friendly process for the synthesis of the umeclidinium bromide API with a higher overall yield (37.8 % versus previously reported overall yield of 9.7 %).


Subject(s)
Muscarinic Antagonists/chemical synthesis , Quinuclidines/chemical synthesis , Carbonates/chemistry , Green Chemistry Technology/methods , Pipecolic Acids/chemical synthesis , Pipecolic Acids/chemistry , Potassium/chemistry , Water/chemistry
2.
Environ Sci Process Impacts ; 20(4): 632-641, 2018 Apr 25.
Article in English | MEDLINE | ID: mdl-29492485

ABSTRACT

In Portovelo in southern Ecuador, 87 gold processing centers along the Puyango-Tumbes River produce an estimated 6 tonnes of gold per annum using a combination of mercury amalgamation and/or cyanidation and processing poly-metallic ores. We analysed total Hg, Hg isotopes, total arsenic, cadmium, copper, lead and zinc in water and sediment along the Puyango in 2012-2014. The highest total mercury (THg) concentrations in sediments were found within a 40 km stretch downriver from the processing plants, with levels varying between 0.78-30.8 mg kg-1 during the dry season and 1.80-70.7 mg kg-1 during the wet season, with most concentrations above the CCME (Canadian Council of Ministers of the Environment) Probable Effect Level (PEL) of 0.5 mg kg-1. Data from mercury isotopic analyses support the conclusion that mercury use during gold processing in Portovelo is the source of Hg pollution found downstream in the Tumbes Delta in Peru, 160 km away. The majority of the water and sediment samples collected from the Puyango-Tumbes River had elevated concentrations of, arsenic, cadmium, copper, lead and zinc exceeding the CCME thresholds for the Protection of Aquatic Life. At monitoring points immediately below the processing plants, total dissolved concentrations of these metals exceeded the thresholds by 156-3567 times in surface waters and by 19-740 times in sediment. The results illustrate a significant transboundary pollution problem involving Hg and other toxic metals, amplified by the fact that the Puyango-Tumbes River is the only available water source in the semi-arid region of northern Peru.


Subject(s)
Environmental Monitoring/methods , Mercury/analysis , Mining , Rivers/chemistry , Water Pollutants, Chemical/analysis , Ecuador , Geologic Sediments/chemistry , Peru
4.
J Orthop Case Rep ; 7(2): 52-56, 2017.
Article in English | MEDLINE | ID: mdl-28819603

ABSTRACT

INTRODUCTION: Systemic capillary leak syndrome (SCLS) is a rare condition of unknown etiology defined by sudden episode of hypotension, high hematocrit, and low serum protein concentration due to capillary hyperpermeability. Several treatments have been published for this pathology and eventual compartment syndrome but not for the disabling consequences. This clinical case highlights the negative orthopedic consequences of a severe systemic attack and reports a subsequent deformity treatment option that resulted in the patient quality of life improvement. To our knowledge, orthopedic surgery for SCLS induced foot and ankle deformity is presented for the first time. CASE REPORT: A 40-year-old Caucasian female patient was referred to our institution for bilateral foot and ankle deformity after compartment syndrome during SCLS attack. She presented a bilateral rigid equino-cavo-varus-adductus deformity causing walk impairment. Bilateral ankle fusion by retrograde nailing was performed in a two-staged procedure. Rigid claw toes were also surgically addressed in an additional procedure. Radiologically, apparent ankle fusion occurred at 3 months post-operative in both sides. Deformity correction allowed the patient to regain walking capacity. A right ankle tibiotalar failed arthrodesis was noticed at 24 months post-operative. Prophylactic human immunoglobulin therapy was initiated after the last surgery with no recurrent attack registered during the 38 months follow-up period. CONCLUSION: Bilateral ankle fusion improved this patient quality of life by restituting walking capacity and lowering the probability of lower limb deformity related ulcers and infections. Major and minor complications are also discussed. This report contributes to the global knowledge about this syndrome and elicits the importance of the induced deformities surgical correction.

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