Yamamoto Chemicals, Inc.

Keiki Chichiishi

Shigeo Fujita

Nobuaki Sasaki

Sayuri Wada

Yasuhisa Iwasaki

The invention provides novel compounds useful as intermediates for the production of polymethine compounds containing a desired counter ion with high purity and in high yields. Thus provided are polymethine ether compounds of the general formula (I) given below and a method of producing polymethine compounds which comprises bringing those compounds into contact with an acid. In the above formula, R represents an alkyl group, an alkoxyalkyl group or an aryl group which may optionally be substituted, Rand Reach independently represents a hydrogen atom, halogen atom, nitro group, alkyl group, alkoxyalkyl group, alkoxy group or alkoxyalkoxy group and Rand Rmay be bound to each other to form a ring; Rrepresents an alkyl group, which may optionally be substituted; L is an alkylene group required for the formation of a ring structure; and X represents a hydrogen atom, halogen atom, alkoxy group, aryloxy group, alkylthio group, arylthio group or substituted amino group.

Polymethine ether compounds

A novel nonsolvate-form crystal of polymethine compound is provided which has good stability in solution, shows a high gram extinction coefficient, is excellent in storage stability, is easy to handle and is highly sensitive to general-purpose semiconductor lasers. Thus is provided a nonsolvate-form crystal of polymethine compound of the formula (I) given below as well as a process for producing the nonsolvate-form crystal of polymethine compound of formula (I) which comprises reacting a polymethine ether compound of the formula (II) given below with hydrochloric acid or hydrobromic acid. (In the above formula, X represents Cl or Br.) (In the above formula, R represents an alkyl group, an alkoxyalkyl group or an optionally substituted aryl group.)

Nonsolvate-form crystal of polymethine compound and process for producing the same

Polymethine ethers

The invention provides near infrared absorbing materials showing high light-to-heat conversion efficiency and high sensitivity to lasers whose emission bands are within the range of 750 nm to 900 nm, original plates for direct printing plate making, and novel compounds which can be applied to such absorbing materials and plates. The compounds are polymethine compounds of the general formula (I) A detailed description of general formula (I) may be found in the specification.wherein Rrepresents an alkoxy group which may be substituted; Rrepresents an alkyl group which may be substituted; Rand Reach represents a lower alkyl group or Rand Rtaken together represent a ring; X represents a hydrogen atom, a halogen atom or a substituted amino group; Y represents an alkoxy group which may be substituted or an alkyl group which may be substituted; Z represents a charge neutralizing ion.

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Yao, Japan

Keiki Chichiishi