摘要:
A process for producing N-formylaspartic anhydride, which comprises, grinding solid aspartic acid into fine particles; and then reacting said finely ground aspartic acid with formic acid and acetic anhydride.
摘要:
A process for producing a high yield of N-carbobenzoxy-L-aspartic anhydride from N-carbobenzoxy-L-aspartic acid in a very short period using commercially acceptable reaction conditions is disclosed. The process is characterized by reacting N-carbobenzoxy-L-aspartic acid with acetic anhydride in the presence of a metal oxide, a metal hydroxide, a metal salt of acid, an organobasic compound or an acid having a dissociation constant of 5.times.10.sup.-2 or more.
摘要:
The reaction between L-aspartic acid and benzyloxycarbonyl chloride is carried out at a specific pH range, i.e., 12.0 to 13.5, whereby highly pure N-benzyloxycarbonyl-L-aspartic acid can be obtained in high yields, while both the by-production of N-benzyloxycarbonyl-.alpha.- or .beta.-L-aspartyl-L-aspartic acid and the decomposition of benzyloxycarbonyl chloride to benzyl alcohol are suppressed.
摘要:
A measuring cylinder into which liquid is supplied is provided with pressure transmitters for sensing the liquid pressure corresponding to the amount thereof. The pressure transmitters are connected with a pressure transformer to transform the pressure into an electric signal for controlling valves to stop and start the supply of liquid into the cylinder. The pressure transmitters are located in the cylinder at different levels and switched to be selectively operated in combination with the pressure transformer. In a preferred embodiment of the invention, the shape of the cylinder is designed so that the diameter thereof increases discretely from the lower part to the upper part thereof. One of the pressure transmitters is located at the bottom of the cylinder and the others are located at levels substantially the same as those at which the diameter of the cylinder increases.
摘要:
A vehicle side section structure that is capable of a required stiffness and enables a reduction in weight of a roof side section is provided. A roof side rail that structures a vehicle side section structure is provided with: a roof outer panel that has length in a vehicle front-rear direction and is opened inward of the vehicle, and has a pair of upper and lower flanges; and a roof side frame member that is joined to the pair of upper and lower flanges of the roof outer panel at a pair of upper and lower flanges. The roof side frame member has, between the upper and lower flanges, an outward protruding portion that is protruded in a vehicle outward direction and an inward protruding portion 46 that is protruded in a vehicle inward direction, and in a sectional view cut orthogonally to the length direction, a length of a top wall of the outward protruding portion is longer than a length of a top wall of the inward protruding portion.
摘要:
A gate circuit has a complementary transistor structure comprising transistors of different conductivity types connected in series respectively between two power source terminals and an output terminal, sharing a gate connected to an input terminal, the transistors of different conductivity types each comprising plural transistors, and the plural transistors being connected in series between each of the two power source terminal and the output terminal. The gate is provided to extend like a line, plural diffusion layers are provided along the direction of the line in which the gate extends, and a conduction channel of each of the plural transistors connected in series between the power source terminals and the output terminal is formed in the diffusion layers.
摘要:
A crystalline L-alpha-aspartyl-L-phenyl-alanine methyl ester product is disclosed. The product is obtained by crystallizing the ester from an aqueous solution, by cooling. The initial concentration of ester in the aqueous solution used provides at least 10 grams of precipitated solid phase per liter of solution. The solution is cooled through conductive heat transfer without effecting forced flow to form a sherbet-like pseudo solid phase.
摘要:
A method for dissolving crystalline L-alpha-aspartyl-L-phenyl-alanine methyl ester product is disclosed. The product is obtained by crystallizing the ester from an aqueous solution, by cooling. The initial concentration of ester in the aqueous solution used provides at least 10 grams of precipitated solid phase per liter of solution. The solution is cooled through conductive heat transfer without effecting forced flow to form a sherbet-like pseudo solid phase.
摘要:
In crystallizing .alpha.-APM from a water solution or a mixed solvent solution of water and a lower alcohol in a crystallizer, the pressure in the crystallizer is held at not higher than atmospheric pressure, a water or water/alcohol mixed solution of .alpha.-APM is fed into the crystallizer with stirring so that the solvent is vaporized, and the crystallization solution is cooled and crystallized by the latent heat of vaporization or is heated so as to prevent supercooling.
摘要:
A method of preparing .varies.-L-aspartyl-L-phenylalanine methyl ester hydrochloride (.varies.-APM.HCL) from a reaction mixture of N-formyl-L-aspartic acid anhydride and L-phenylalanine methyl ester (PM), wherein .alpha.-APM.HCl is produced without isolating an intermediate by solid-liquid separation during the course of the reaction process.