Novel method for preparing phenolic hydroxyl substituted compound

Abstract

An image signal generation portion 10 generates an image signal DVb of a variable frame-rate picked-up image whose frame rate can be varied. A frame rate conversion portion 30 converts a frame rate of an image signal DVu supplied to it into a frame rate of the image signal DVb and synchronizes them to provide an image signal DVw. A monitor image signal generation portion 40 uses the image signalsDVb and DVw to generate an image signal DVmix of an image in which an image based on the image signal DVb and an image based on the image signal DVw are mixed and output it as a monitor image signal DMTout or SMTout. Alternatively, it generates an image signal DVwp of an image in which a part of an image based on the image signal DVb is replaced by an image based on the image signal DVw and outputs it as the monitor image signal DMTout or SMTout. It is possible to simultaneously display a variable frame-rate picked-up image and an image having a different frame rate.

Description

technical field The present invention relates to a process for the preparation of phenolic hydroxy-substituted compounds of general formula (I) by dealkylating alkylaryl ethers of general formula (II) by treatment with a thiourea / aluminum chloride reagent pair. In the general formula, R 1 Represents straight chain or branched chain C 1-6 Alkyl; R 2 , R 3 , R 4 , R 5 and R 6 have the same or different meanings and represent hydrogen or halogen atoms, hydroxyl, carboxyl, nitro, oxo, C 1-6 Alkylcarbonyl, straight chain or branched chain alkyl or straight chain or branched chain alkoxy, or aryl, or R 2 and R 3 Taken together to represent a 5-7 membered ring or a fused ring system; the 5-7 membered ring may be a partially saturated ring optionally substituted by an oxo group or may be an unsaturated ring; or the fused The ring-closing system can form a steroid compound with the first ring, preferably at the 17th position optionally by an oxo group or C 1-6 Alkylcarbonylox...

AI Technical Summary

Problems solved by technology

Besides these advantages, this method has several disadvantages: the AlCl 3 The / EtSH reagent pair needs to be used in a 3-6 fold excess based on the amount of ether to be demethylated; The ether (which is supposed to be formed in the reaction) needs to be removed by oxidation; the thio compound used and formed in the reaction has a low boiling point and likewise has an unpleasant odor at low concentrations, which leads to increased costs to provide Environmentally acceptable operation, and any operation error can lead to air pollution

However, this method has an undoubted disadvantage: the use of thiol reagents with a strong unpleasant smell

Images