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[9] [10] [11] Both of them obtained piperidine by reacting piperine with nitric acid. Industrially, piperidine is produced by the hydrogenation of pyridine, usually over a molybdenum disulfide catalyst: [12] C 5 H 5 N + 3 H 2 → C 5 H 10 NH. Pyridine can also be reduced to piperidine via a modified Birch reduction using sodium in ethanol. [13]
The following chart shows the solubility of various ionic compounds in water at 1 atm pressure and room temperature (approx. 25 °C, 298.15 K). "Soluble" means the ionic compound doesn't precipitate, while "slightly soluble" and "insoluble" mean that a solid will precipitate; "slightly soluble" compounds like calcium sulfate may require heat to precipitate.
Due to its poor solubility in water, piperine is typically extracted from black pepper by using organic solvents like dichloromethane. [5] The amount of piperine varies from 1–2% in long pepper, to 5–10% in commercial white and black peppers.
The nearer two molecules are in this three-dimensional space, the more likely they are to dissolve into each other. To determine if the parameters of two molecules (usually a solvent and a polymer) are within range, a value called interaction radius is given to the substance being dissolved. This value determines the radius of the sphere in ...
Dimethylpiperidines are derivatives of the heterocycle piperidine, wherein two hydrogen atoms are replaced by methyl groups. The 2,6-dimethylpiperidines are prepared by reduction of 2,6-dimethylpyridine (2,6-lutidine). The achiral isomer is the predominant isomer produced in this reaction.
Specific gravity is defined as the density of the solvent divided by the density of water at the same temperature. As such, specific gravity is a unitless value. It readily communicates whether a water-insoluble solvent will float (SG < 1.0) or sink (SG > 1.0) when mixed with water.
For comparison, crystalline benzene is also orthorhombic, with space group Pbca, a = 729.2 pm, b = 947.1 pm, c = 674.2 pm (at 78 K), but the number of molecules per cell is only 4. [18] This difference is partly related to the lower symmetry of the individual pyridine molecule (C 2v vs D 6h for benzene).
Lobeline is a piperidine alkaloid found in a variety of plants, particularly those in the genus Lobelia, including Indian tobacco (Lobelia inflata), Devil's tobacco (Lobelia tupa), great lobelia (Lobelia siphilitica), Lobelia chinensis, and Hippobroma longiflora. In its pure form, it is a white amorphous powder which is freely soluble in water.