摘要:
A process for reducing the level of tri-substituted phosphine, arsine and/or stibine oxide from a mixture comprising a desired product and at least one such oxide is provided, comprising the addition of a metal salt to the mixture to form a complex with the oxide, and removing the complex from the mixture. This process has particular utility for removing triphenylphosphine oxide from a mixture--a task that was previously hard to perform.
摘要:
A process for preparing enantiomerically pure esters of the formula I (Ia and Ib) where the substituents have the following meanings: R1 hydrogen or substituted or unsubstituted C1-C6-alkyl, C1-C6-alkoxy or Cl-C6-alkanoyl, R2 and R3 independently of one another hydrogen or substituted or unsubstituted C1-C6-alkyl, C1-C6-alkoxy, C1-C6-alkanoyl, C1-C6-alkylthio, C1-C6-alkylsulfinyl or C1-C6-alkylsulfonyl, R4 and R5 R4≠R5 and independently of one another hydrogen or substituted or unsubstituted C1-C6-alkyl or R4 and R5 form together with the carbon atoms to which they are bonded a substituted or unsubstituted C3-C6-cycloalkylidene, R6 substituted or unsubstituted aryl, C1-C20-alkyl, C3-C20-alkenyl, C3-C20-alkynyl, C1-C20-alkoxy-C1-C20-alkyl comprises converting racemic compounds of the formula II, where the substituents R1 to R5 have the abovementioned meanings, with a lipase or esterase in the presence of vinyl esters of the formula III, where R6 has the abovementioned meaning, and R7 is hydrogen or methyl, into compounds of the formula I.
摘要:
An improved process for the preparation of 1,2,4-triazolo[1,5-a]pyrimidine compounds comprising the reaction involving a compound of formula II and a compound of formula III in the presence of an oxidizing agent and a reducing agent, wherein a metal salt is added to form a complex with the oxidized reducing agent produced in the process, and this complex is separated from the desired product.
摘要:
A process for preparing enantiomerically pure alcohols of the formula I (Ia or Ib) where the substituents have the following meanings: R1 hydrogen or substituted or unsubstituted C1-C6-alkyl, C1-C6-alkoxy or C1-C6-alkanoyl, R2 and R3 independently of one another hydrogen or substituted or unsubstituted C1-C6-alkyl, C1-C6-alkoxy, C1-C6-alkanoyl, C1-C6-alkylthio, C1-C6-alkylsulfinyl or C1-C6-alkylsulfonyl, R4 substituted or unsubstituted C1-C6-alkyl, C3-C8-cycloalkyl, which comprises reducing compounds of the formula II where the substituents R1 to R4 have the abovementioned meanings in aqueous solution in the presence of a carbon source and of a microorganism or of a reducing agent, of a cofactor and of an enzyme, to compounds of the formula I.