Takeda Chemical Industries, Inc.

Toru Ishida

Masayasu Kato

Taiiti Okada

A substantially solvent-free and stable crystal of the compound of the formula: ##STR1## wherein the ring A may optionally be substituted, R.sup.1 represents hydrogen or an N-protecting group, each of R.sup.2, R.sup.3 and R.sup.4 (1) a hydrogen atom, (2) an alkyl group which may optionally be substituted with halogen atom(s) or (3) an alkoxy group which may optionally be substituted with halogen atom(s) or alkoxy; or its salt, is produced by subjecting a solvate of the compound (I) or its salt to de-solvent treatment, in an industrially advantageous method.

Crystals of benzimidazole derivatives and their production

A diphenylmethane compound (III) can be produced in a good yield by allowing a phenol compound (I) to react with a stilbene compound (II) in the presence of methanesulfonic acid ##STR1##

Process for preparing diphenylmethane compounds

An improved industrial process for producing a compound of the general formula: ##STR1## wherein R is an alkyl group having 1 to 4 carbon atoms which comprises reacting a compound of the general formula: ##STR2## wherein R is as defined above with nitrous acid in a mixed solvent of water and a water-insoluble or slightly soluble organic solvent.

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Takarazuka, Japan

Toru Ishida