7 research outputs found

    Crystal structures of two formamidinium hexafluoridophosphate salts, one with batch-dependent disorder

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    Syntheses of the acyclic amidinium salts, morpholinoformamidinium hexafluoridophosphate [OC4H8N—CH=NH2]PF6 or C5H11N2O+·PF6−, 1, and pyrrolidinoformamidinium hexafluoridophosphate [C4H8N—CH= NH2]PF6 or C5H11N2+·PF6−, 2, were carried out by heating either morpholine or pyrrolidine with triethyl orthoformate and ammonium hexafluoridophosphate. Crystals of 1 obtained directly from the reaction mixture contain one cation and one anion in the asymmetric unit. The structure involves cations linked in chains parallel to the b axis by N—H...O hydrogen bonds in space group Pbca, with glide-related chains pointing in opposite directions. Crystals of 1 obtained by recrystallization from ethanol, however, showed a similar unit cell and the same basic structure, but unexpectedly, there was positional disorder [occupancy ratio 0.639 (4):0.361 (4)] in one of the cation chains, which lowered the crystal symmetry to the non-centrosymmetric space group Pca21, with two cations and anions in the asymmetric unit. In the pyrrolidino compound, 2, cations and anions are ordered and are stacked separately, with zigzag N—H...F hydrogen-bonding between stacks, forming ribbons parallel to (101), extended along the b-axis direction. Slight differences in the delocalized C=N distances between the two cations may reflect the inductive effect of the oxygen atom in the morpholino compound

    Data on trend changes of drinking groundwater resources quality: A case study in Abhar

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    The data of this study was to determine the groundwater quality trend changes in Abhar city (Iran) during one decade (2002–2016). In the first and end year of the study period, the Mean±SD of total hardness (as calcium carbonate, mg/l), electrical conductivity (as micromhos/cm) and total dissolved solid in the first and end year of the study period were 192.69±56.83, 235.25±84.73 and 606.21±194.69, 744.55±288.52 and 348.79±106.81, 464.71±183.52 respectively. On the basis of Pearson correlation coefficient, the ascending trend of some parameters concentration with time was significant at the level of 95% of confidence limits (α ≤ 0.05). Keywords: Trend changes, Drinking water, Groundwater, Abhar, Water resource

    NMR Determination of Enantiomeric Composition of Chiral Alcohols Using Camphorsulfonate Esters

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    Most biologically active compounds, including pharmaceuticals, have chiral molecular structures. With increased recognition that enantiomers of chiral drugs are metabolized differently, there has been enormous interest in the development of enantioselective methodologies for the synthesis of chiral compounds. NMR spectroscopy has emerged as a powerful method for discrimination of enantiomers of chiral compounds. 1 One strategy by which the NMR method is exploited is based on converting the enantiomers of a chiral compound to diastereomers using a chiral derivatizing agent. These diastereomers often display anisochronous NMR signals, which can be identified and integrated affording quantitative measurements of the optical purity of a sample

    Direct Preparation of Amides from Amine Hydrochloride Salts and Orthoesters: A Synthetic and Mechanistic Perspective

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    <div><p></p><p>The conversion of a wide range of primary and secondary aliphatic and a few arylamine hydrochloride salts to their corresponding acetamides with trimethyl orthoacetate is described. Mechanistic studies using NMR and gas chromatography–mass spectrometry techniques indicate these reactions proceed via an <i>O</i>-methylimidate intermediate that undergoes in situ demethylation by chloride, affording the corresponding acetamides. Synthetically, this reaction represents a practical, high-yielding protocol with a simple workup for the rapid conversion of amine hydrochloride salts to acetamides.</p></div

    The association of cigarette smoking and pathological response to neoadjuvant platinum-based chemotherapy in patients undergoing treatment for urinary bladder cancer - A prospective European multicenter observational study of the EAU Young Academic Urologists (YAU) urothelial carcinoma working group.

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    OBJECTIVE To prospectively study the impact of smoking on pathological response to neoadjuvant chemotherapy (NAC) in patients undergoing radical cystectomy (RC) for urothelial carcinoma of the bladder (UCB). MATERIALS & METHODS We collected standard clinicopathological variables, including smoking status (never, former, current) in patients undergoing NAC and RC for UCB at 12 European tertiary care centers between 12/2013-12/2015. Clinicopathological variables were compared according to smoking status. Multivariable logistic regression models were built to assess the association of smoking status and a) complete (no residual disease), b) partial (residual, non-muscle invasive disease), c) no pathological response (residual muscle invasive or lymph node positive disease). Kaplan-Meier and Cox regression analyses were employed to study the impact of response to NAC on survival. RESULTS AND LIMITATIONS Our final cohort consisted of 167 NAC patients with a median follow-up of 15 months (interquartile range (IQR) 9-26 months) of whom 48 (29%), 69 (41%), and 50 (30%) where never, former, and current smokers, respectively. Smoking was significantly associated with advanced age (p = 0.013), worse ECOG performance status (p = 0.049), and decreased pathological response to NAC (p = 0.045). On multivariable logistic regression analyses, former and current smoking status was significantly associated with lower odds of complete pathological response (odds ratio (OR) 0.37, 95% confidence interval (CI) 0.16-0.87, p = 0.023, and OR 0.34, 95% CI 0.13-0.85, p = 0.021), while current smoking status was significantly associated with a greater likelihood of no pathological response (OR 2.49, 95% CI 1.02-6.06, p = 0.045). Response to NAC was confirmed as powerful predictor of survival. CONCLUSIONS Smoking status is adversely associated with pathological response to NAC. Smokers should be informed about these adverse effects, counseled regarding smoking cessation, and possibly be considered for immunotherpeutics as they may be more effective in smokers
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