Yoshitomi Pharmaceutical Industries, Ltd.

Kunihide Oka

Masayoshi Gohbayashi

Kazumi Saeki

Masanori Kohara

Takanori Miura

Kazuto Tsukinuki

Masami Hirano

Fumihide Izumi

Masaya Tanaka

Koichi Takee

Setsuo Oikawa

Masayoshi Marutani

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.

Alpha crystals of tetrakis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)

Novel individual .alpha.-form particle crystals of tetrakis[3-(3,5,-di-t-butyl-4-hydroxyphenyl)propionyloxymethyl]methane and process for its production are disclosed.

Individual .alpha.-form particle crystals of

In producing ester compound useful as an antioxidant for organic materials which are represented by the formula: ##STR1## wherein R.sup.1 and R.sup.2 are the same or different and represent 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 transesterification, monoalkyltin compounds are used as a catalyst, whereby the ester compounds can be produced with high quality and in high yields.

Process for the production of ester compounds

Novel crystalline form of n-octadecyl-3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate with improved transportability, measurability and workability is disclosed.

N-octadecyl-3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate with a novel

An improved process for the production of penicillic acid compounds, especially chloromethyl ester of penicillin G, penicillin V or sulbactam is disclosed.

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Nakatsu, Japan

Kunihide Oka