A gas discharge tube, wherein a stem (4) forming a sealed case for the gas discharge tube is provided with a flange portion (4A) integral therewith, this enabling a lamp assembling operation to be simplified without requiring an operation for combining and fixing the flange portion (4A) with and to the gas discharge tube, the gas discharge tube to be easily mass-produced, and, moreover, a positioning hole (22) provided in advance in the flange (4A) to be utilized to fix the gas discharge tube (1) to an external stem setting portion (17), whereby a more accurate lamp setting operation can be carried out.

Gas discharge tube

Elastic knitted cloth

PURPOSE:To prepare the titled compound useful as an intermediate antiallergic agent, etc., safely in short reaction time, easily collecting the by-produced hydrogen sulfide, by reacting 2,6-lutidine with aniline in the presence of sulfur, and hydrolyzing the product. CONSTITUTION:6-Methylpicolinic acid is prepared by reacting 1mol of 2,6-lutidine with preferably 1-2mol of ammonia at about 160-170 deg.C, in the presence of preferably 3-4mol of sulfur, and hydrolyzing the resultant N-phenyl-60-methyl-2- pyridinecarbothioamide. EFFECT:The reaction can be carried out without sing a heavy metal oxidizing agent, and the by-produced hydrogen sulfide can be collected easily by introducing into an alkaline solution. Accordingly, the objective produce can be produced safely, without causing environmental pollution.

Novel method for preparation of pyridine derivative

The gas discharge tube in accordance with the present invention comprises at least two electrically conductive aperture members disposed within a thermoelectron transmission path between a cathode and an anode, and an insulator for electrically insulating the electrically conductive aperture members from each other, thereby being able to emit light with a high luminance. Its startability at the time of emitting light can be enhanced in particular when the aperture area of the electrically conductive aperture member on the downstream side in the thermoelectron transmission path is set favorably.

Gas discharge tube having insulator between aperture members

A method for separating and recovering an aromatic aldehyde from a mixture thereof that also contains tar and light and heavy impurities, includes feeding the liquid flow containing this mixture into an evaporator, vaporizing the mixture in order to separate, on the one hand, a gaseous flow containing the aromatic aldehyde, the light impurities, the heavy impurities that can be vaporized at the selected evaporation temperature and pressure and, on the other hand, a liquid flow essentially containing the tar, and recovering the aromatic aldehyde from the separated gaseous flow.

Separation of aromatic aldehydes

NEW MATERIAL:5-n-Butyl-2-thiopicolineanilide of formula. USE:Raw materials for preparing fusaric acid useful as hypotensives, capable of giving the high-purity fusaric acid in high yield, when heated in an aqueous sodium hydroxide or sulfuric acid to hydrolyze the thioanilide group. PROCESS:0.5-3.0 moles of aniline is reacted with a mixture of 1 mole of 2-methyl- 5-n-butylpyridine and 0.5-6.0 gram-atoms of sulfur at 100-200 deg.C to give the compound of the formula.

55nnbutyll22thiopicolineeanilide and its preparation

PURPOSE:To prepare the title compound useful as an intermediate of medicine, pesticide, perfumery, etc., easily and economically, by treating p-aminobenzaldehyde and/or its polymer with a mineral acid in a specific solvent, diazotizing the product at low temperature, and hydrolyzing the diazotized compound. CONSTITUTION:The title compound is prepared by (1) reacting p-aminobenzaldehyde and/or its polymer obtained by the reaction of p-nitrotoluene with sodium polysulfide in an alkaline aqueous solution containing an alcohol, with a mineral acid such as sulfuric acid, etc. in a solvent composed of a water-soluble organic solvent such as alcohol, cyclic ether, lower fatty acid, etc. and water, (2) diazotizing the reaction product at a low temperature by conventional process, and (3) hydrolyzing the diazotized product. The weight ratio of the organic solvent to p-aminobenzaldehyde is pref. 1.5-5 to 1; the molar ratio of the mineral acid to the aldehyde is pref. 1.0-2.0 to 1; and the volume ratio of water to the organic solvent is pref. 0.1-50 to 1.

Preparation of paraahydroxybenzaldehyde

PURPOSE:To prepare the title compound useful as an intermediate of drugs, in high purity and yield, by treating an alkaline aqueous solution of p-hydroxybenzaldehyde successively with an organic solvent which is insoluble or slightly soluble in water, and with an alkaline aqueous solution, and crystallizing the objective compound at a specific pH. CONSTITUTION:An aqueous solution or solid of crude p-hydroxybenzaldehyde obtained by various processes, is dissolved in an organic solvent which is insoluble or slightly soluble in water and is a good solvent of the p-hydroxybenzaldehyde (e.g. diethyl ether, pref. methyl isobutyl ketone). The pH of the solution is adjusted to >=10 by adding an alkaline aqueous solution. After separating the mixture into two phases, the alkaline aqueous solution layer is added with a mineral acid to attain a pH value of 4-7, pref. 5.5-6.5. The crystallized p-hydroxybenzaldehyde is separated and purified.

Takemori Shinichi

Papers

55nnbutyll22thiopicolineeanilide and its preparation

Preparation of paraahydroxybenzaldehyde

Purification of pphydroxybenzaldehyde