The present invention generally relates to novel synthetic methods, systems, kits, salts, and precursors useful in medical imaging. In some embodiments, the present invention provides compositions comprising an imaging agent precursor, which may be formed using the synthetic methods described herein. An imaging agent may be converted to an imaging agent using the methods described herein. In some cases, the imaging agent is enriched in .sup.18F. In some cases, an imaging agent including salt forms (e.g., ascorbate salt) may be used to image an area of interest in a subject, including, but not limited to, the heart, cardiovascular system, cardiac vessels, brain, and other organs.

Disclosed herein are embodiments of aryl compounds and polymers thereof that are made using methods that do not require harsh conditions or expensive reagents. The methods disclosed herein utilize precursor compounds that can be polymerized to form polycyclic aromatic hydrocarbons and polymers, such as carbon-based polymers like nanostructures (e.g., graphene or graphene-like nanoribbons).

Disclosed herein are embodiments of aryl compounds and polymers thereof that are made using methods that do not require harsh conditions or expensive reagents. The methods disclosed herein utilize precursor compounds that can be polymerized to form polycyclic aromatic hydrocarbons and polymers, such as carbon-based polymers like nanostructures (e.g., graphene or graphene-like nanoribbons).

The present invention relates to an N,N′-diurea derivative represented by the following general formula (1) and a method for producing the same. In addition, the present invention relates to a thermosensitive recording material in which a thermosensitive recording layer including a basic dye which is colorless or lightly colored at room temperature and a developer capable of developing color upon contact with the basic dye by heating is provided on a base sheet, wherein the developer is the N,N′-diurea derivative represented by the following general formula (1):

##STR00001##

(wherein R2 is an alkyl group, an aralkyl group, or an aryl group; and A1 is a hydrogen atom or an alkyl group).

The present invention relates to an N,N′-diurea derivative represented by the following general formula (1) and a method for producing the same. In addition, the present invention relates to a thermosensitive recording material in which a thermosensitive recording layer including a basic dye which is colorless or lightly colored at room temperature and a developer capable of developing color upon contact with the basic dye by heating is provided on a base sheet, wherein the developer is the N,N′-diurea derivative represented by the following general formula (1):

##STR00001##

(wherein R2 is an alkyl group, an aralkyl group, or an aryl group; and A1 is a hydrogen atom or an alkyl group).

The present disclosure provides preparation method for water-soluble magnolol derivatives and honokiol derivatives and intermediates thereof, and related monohydroxy protection intermediates. The nitrification intermediate has a structure shown in Formula I. Formula I is

##STR00001##

R.sub.2 is a hydroxyl, and R.sub.3 is H; or, R.sub.2 is H, and R.sub.3 is a hydroxyl; and R.sub.1 and R.sub.4 are independently selected from C.sub.1˜C.sub.12 electron donor groups. The preparation method includes the following steps: performing monohydroxy protection on a compound A

##STR00002##

with a hydroxy protection reagent in the presence of an acid binding agent to form a monohydroxy protection compound, herein R.sub.1, R.sub.2, R.sub.3 and R.sub.4 in the compound A have the same definition as above, and the hydroxy protection reagent is p-toluenesulfonyl chloride and 1-hydroxybenzotriazole; and performing a nitrification reaction and a deprotection reaction on the monohydroxy protection compound successively to obtain the nitrification intermediate.

The present disclosure provides preparation method for water-soluble magnolol derivatives and honokiol derivatives and intermediates thereof, and related monohydroxy protection intermediates. The nitrification intermediate has a structure shown in Formula I. Formula I is

##STR00001##

R.sub.2 is a hydroxyl, and R.sub.3 is H; or, R.sub.2 is H, and R.sub.3 is a hydroxyl; and R.sub.1 and R.sub.4 are independently selected from C.sub.1˜C.sub.12 electron donor groups. The preparation method includes the following steps: performing monohydroxy protection on a compound A

##STR00002##

with a hydroxy protection reagent in the presence of an acid binding agent to form a monohydroxy protection compound, herein R.sub.1, R.sub.2, R.sub.3 and R.sub.4 in the compound A have the same definition as above, and the hydroxy protection reagent is p-toluenesulfonyl chloride and 1-hydroxybenzotriazole; and performing a nitrification reaction and a deprotection reaction on the monohydroxy protection compound successively to obtain the nitrification intermediate.

Disclosed herein are embodiments of aryl compounds and polymers thereof that are made using methods that do not require harsh conditions or expensive reagents. The methods disclosed herein utilize precursor compounds that can be polymerized to form polycyclic aromatic hydrocarbons and polymers, such as carbon-based polymers like nanostructures (e.g., graphene or graphene-like nanoribbons).

Disclosed herein are embodiments of aryl compounds and polymers thereof that are made using methods that do not require harsh conditions or expensive reagents. The methods disclosed herein utilize precursor compounds that can be polymerized to form polycyclic aromatic hydrocarbons and polymers, such as carbon-based polymers like nanostructures (e.g., graphene or graphene-like nanoribbons).

A process for preparing a compound represented by Formula [1], the process comprising a step of hydrolyzing a compound represented by Formula [2] under an acidic or basic condition, and a step of reacting a compound represented by Formula [3] with a metal acetate salt, and a step of halogenating a compound represented by Formula [4]; a process for preparing a compound represented by Formula [1] comprising a step of reacting a compound represented by Formula [3] with a metal acetate salt, and then, adding alcohol, water, or base to the reaction solution to perform reaction; a process for preparing a compound represented by Formula [1] comprising a step of reacting a compound represented by Formula [3] under a presence or absence of a base, an ionic liquid and a metal sulfate salt, in water or a mixed solvent of water and an organic solvent; a compound represented by Formula [2] or a salt of the same; and a compound represented by Formula [3] or a salt of the same.