Hitachi, Ltd.

Sumitomo Chemical Company, Limited

Ono Pharmaceutical Co., Ltd.

Susumu Ohtsuka

Naonori Hirata

Kenji Arai

Masao Shiroshita

Mitsunori Hiratsuka

Yasunobu Miyamoto

Hiroaki Hibino

Itsuo Okumoto

Atsushi Yoshioka

Tomishige Yatsugi

Tomoyasu Yoshida

Eiji Moro

Takeo Ohkouchi

Yoichi Ito

Yukihiko Ozaki

Fumihiko Yamanushi

Yoshitaka Okada

A process for producing a dicarboxylic acid compound represented by the formula (4): wherein Rand Rare the same or different and each represents lower alkyl and the wavy line indicates that this compound is the E- or Z-isomer or a mixture of them, characterized by reacting a compound represented by the formula (2): wherein R, Rand the wavy line have the same meanings as the above, and one of Xand Xrepresents hydrogen and the other represents halogen, with nitrophenol represented by the formula (3): in the presence of a base; a process for producing a nitrochromone compound represented by the formula (5): wherein Rhas the same meaning as the above, characterized by reacting the dicarboxylic acid compound or carboxylic acid thereof with an acid; a process for producing an aminochromone compound which comprises reducing the nitrochromone compound; and a process for producing an amidochromone compound which comprises acylating the aminochromone compound are provided.

Process for producing chromone compound

There is provided an industrially advantageous process for producing a 1-chloro-4-arylbutane represented by the general formula (2):wherein R represents hydrogen, lower alkyl, or lower alkoxy, characterized by reacting 1-bromo-3-chloropropane with a compound represented by the general formula (1):wherein R is as defined above; and X represents chlorine, bromine, or iodine, in a solvent.

Process for producing 1-chloro-4-arylbutane

A recording or reproducing of an input video signal is prohibited in a recording mode operation when a recording inhibition signal is attached thereto and, when a mode other than the recording mode is set, the video signal of optimum level can be supplied to a television receiver even if the recording inhibition signal is attached to the video signal so that a sufficient monitoring becomes possible.

Magnetic recording and reproducing apparatus with recording inhibition

In a magnetic recording and reproducing apparatus, amplitude errors of recording currents respectively supplied to a plurality of rotary magnetic heads are detected, and, in individual periods of sequential scanning of a magnetic recording medium by the plural rotary magnetic heads, the gain of a variable gain amplifier disposed in a signal recording system sequentially supplying an input video signal to the plural rotary magnetic heads is controlled so as to automatically adjust the value of the recording current supplied to each of the rotary magnetic heads.

Magnetic recording and reproducing apparatus with individual correction

A demagnetizing circuit of a home use video tape recorder is controlled by using means such as a control by a microcomputer or the like so as to execute a demagnetizing operation in a desired tape position interval. Further, by properly controlling an onscreen-display on a monitor display screen or a display on a VTR display tube, the operating efficiency is further improved.

Video tape recorder having a special demagnetizing function

A reproducing circuit for use in a magnetic recording and reproducing apparatus having a recording circuit operable to record a video luminance signal in either a conventional recording mode or in a High-Band mode has a first automatic gain control circuit for holding a level of a reproduced FM signal at an input thereof constant, a recording mode determination circuit having an input connected to the first automatic gain control circuit and responsive to an output of the first automatic gain control circuit for determining which the first or second recording mode is used to record the FM signal under reproduction, a first equalizer circuit for equalizing the reproduced FM signal suitably for the first recording mode, a second equalizer circuit for equalizing the reproduced FM signal suitably for the second recording mode, a switch circuit for selecting an output of either the first equalizer circuit or the second equalizer circuit according to an output of the recording mode determination circuit, a second automatic gain control circuit for holding an output level of the switch circuit, whereby the recording mode of the signal undergoing reproduction is automatically determined and the characteristics of the reproducing circuit is changed automatically suitably.

Magnetic recording/reproducing apparatus

Compounds of the present invention are represented by the formula, ##STR1## wherein X represents a lower alkyl, lower alkoxy, lower haloalkyl or lower haloalkoxy group or a halogen atom, and R.sup.1 and R.sup.2, which may be the same or different, represent a hydrogen atom or a methyl group. They are useful intermediates for preparing herbicidal compounds.

.beta.-hydroxyketone and its production

Beta-hydroxyketone and its production

Growing community of inventors

Ibaraki, Japan

Susumu Ohtsuka