摘要:
A process for the production of penicllic acid compounds, especially chloromethyl ester of penicillin G, penicillin V or sulbactam by esterification in the presence of a phase transfer catalyst of the general formula (R¹)(R²)(R³) (R⁴)NX (III) wherein R¹, R², R³ and R⁴ are the same or different and each is an alkyl or aralkyl group and X is a hydroxide, chloride, bromide or hydrogensulfate ion.
摘要:
Novel individual α-form particle crystals of tetrakis[3-(3,5-di-t-butyl-4-hydroxyphenyl)propionyloxymethyl]methane and process for its production are disclosed.
摘要:
The invention provides alpha crystals of tetrakis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyloxymethyl]methane that occur as round granular crystals with high purity, uniform grain size, narrow grain size distribution and good flowability.
摘要:
The invention provides alpha crystals of tetrakis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyloxymethyl]methane that occur as round granular crystals with high purity, uniform grain size, narrow grain size distribution and good flowability.
摘要:
In producing ester compunds useful as an antixidant for organic materials which are reperesented by the formula: , wherein R¹ and R² are the same or different hydrogen or straight or branched chain alkyl radicals containing 1 - 8 carbon atoms, Z is an organic radical derived from an n-hydroxy alcohol, and n denotes an integer of 1 to 4, by the transesterification, monoalkyltin compounds are used as a catalyst, whereby the ester compounds can be produced with high quality and in high yields.
摘要:
Novel crystalline form of n-octadecyl-3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate with improved transportability, measurability and workability is disclosed.
摘要:
In producing ester compunds useful as an antixidant for organic materials which are reperesented by the formula: , wherein R¹ and R² are the same or different hydrogen or straight or branched chain alkyl radicals containing 1 - 8 carbon atoms, Z is an organic radical derived from an n-hydroxy alcohol, and n denotes an integer of 1 to 4, by the transesterification, monoalkyltin compounds are used as a catalyst, whereby the ester compounds can be produced with high quality and in high yields.