102 results about "Potassium methoxide" patented technology

A method of preparing a bis(thio-hydrazide amide) disalt includes the steps of combining a neutral bis(thio-hydrazide amide), an organic solvent and a base to form a bis(thio-hydrazide amide) solution; and combining the solution and methyl tert-butyl ether, thereby precipitating a disalt of the bis(thio-hydrazide amide).In some embodiments, a method of preparing a bis(thio-hydrazide amide) disalt includes the steps of combining a neutral bis(thio-hydrazide amide) and an organic solvent selected from methanol, ethanol, acetone, and methyl ethyl ketone to make a mixture; adding at least two equivalents of a base selected from sodium hydroxide, potassium hydroxide, sodium methoxide, potassium methoxide, sodium ethoxide and potassium ethoxide to the mixture, thereby forming a solution; and combining the solution and methyl tert-butyl ether to precipitate the disalt of the bis(thio-hydrazide amide).The disclosed methods do not require lyophilization and the solvents used in the process can be more readily removed to low levels consistent with pharmaceutically acceptable preparation.

The invention relates to a method for preparing methyl 3-methoxypropionate. The molar ratio of raw material methanol to MA is 2.0 to 3.0:1, and sodium methoxide or potassium methoxide is used as a catalyst. 5.3~14.3%; first add the required amount of catalyst and methanol into the reactor, add the required MA into it for at least 10 hours under strong stirring, continue the reaction for 2~6 hours, and the reaction temperature is 45~60°C; the reaction is over Finally, under cooling and stirring, to the above reaction product, add concentrated sulfuric acid or 85% phosphoric acid to neutralize the catalyst in an amount of 1 / 2 or 1 / 3 of the molar amount of the catalyst, and maintain the temperature ≤ 35°C; Purified to obtain the target product. The mol ratio of this preparation method methyl alcohol and MA is 2.4-2.6: 1, and sodium methylate consumption is 10-11% (wt) of methanol amount, and reaction temperature is 54-56 ℃, and the reaction time is 14 hours, and wherein MA feed time is After 12 hours, the recovered product front fraction can be recycled, which has the advantages of high yield, simple refining and less catalyst consumption.