A method of forming dialkyl carbonate is provided, which includes introducing carbon dioxide into a catalyst to form dialkyl carbonate, wherein the catalyst is formed by activating a catalyst precursor using alcohol, wherein alcohol is R.sup.3—OH, and R.sup.3 is C.sub.1-12 alkyl group or C.sub.5-12 aryl or heteroaryl group. The catalyst precursor is formed by reacting Sn(R.sub.1).sub.2(L).sub.2 and Ti(OR.sup.2).sub.4, and Sn(R.sup.1).sub.2(L).sub.2 and Ti(OR.sup.2).sub.4 have a molar ratio of 1:2 to 2:1. R.sup.1 is C.sub.1-10 alkyl group, R.sup.2 is H or C.sub.1-12 alkyl group, and L is O—(C═O)—R.sup.5, and R.sup.5 is C.sub.1-12 alkyl group. The dialkyl carbonate is ##STR00001##

A method of forming dialkyl carbonate is provided, which includes introducing carbon dioxide into a catalyst to form dialkyl carbonate, wherein the catalyst is formed by activating a catalyst precursor using alcohol, wherein alcohol is R.sup.3—OH, and R.sup.3 is C.sub.1-12 alkyl group or C.sub.5-12 aryl or heteroaryl group. The catalyst precursor is formed by reacting Sn(R.sub.1).sub.2(L).sub.2 and Ti(OR.sup.2).sub.4, and Sn(R.sup.1).sub.2(L).sub.2 and Ti(OR.sup.2).sub.4 have a molar ratio of 1:2 to 2:1. R.sup.1 is C.sub.1-10 alkyl group, R.sup.2 is H or C.sub.1-12 alkyl group, and L is O—(C═O)—R.sup.5, and R.sup.5 is C.sub.1-12 alkyl group. The dialkyl carbonate is ##STR00001##

The presently claimed invention relates to a process for purification of aroma compounds by distillation. Specifically, it relates to a process for purification of carbonic esters of formula (I) using a combination of distillative processes.

The presently claimed invention relates to a process for purification of aroma compounds by distillation. Specifically, it relates to a process for purification of carbonic esters of formula (I) using a combination of distillative processes.

The present invention relates to a process for preparing an organic carbonate, comprising contacting carbon dioxide with an alcohol in the presence of water and a catalyst in a reaction zone resulting in the production of the organic carbonate, wherein the organic carbonate is continuously removed from the reaction zone.

The present invention relates to a process for preparing an organic carbonate, comprising contacting carbon dioxide with an alcohol in the presence of water and a catalyst in a reaction zone resulting in the production of the organic carbonate, wherein the organic carbonate is continuously removed from the reaction zone.

A phenyl-containing compound, an intermediate thereof, a preparation method therefor and an application thereof. Provided is a compound represented by formula I or a pharmaceutically acceptable salt thereof, where R.sup.1, R.sup.2, R.sup.3, R.sup.4 and R.sup.5 are independently hydrogen, C.sub.1-C.sub.6 alkyl, C.sub.1-C.sub.6 alkoxy or C(═O)OR.sup.8; where R.sup.8 is C.sub.1-C.sub.4 alkyl; R.sup.6 is (II), (III) or (IV); and R.sup.7 is —OH, —NH.sub.2, —NHCH.sub.3, —N(CH.sub.3).sub.2 or C.sub.1-4 alkoxy. The compound has a low critical micelle concentration (CMC) and good dilution resistance and is capable of enclosing an insoluble drug to form a small-molecule micelle having a high drug loading capacity and good stability.

##STR00001##

The present invention relates to a process for preparation of 2-Amino-5-hydroxy propiophenone, a key intermediate for the synthesis of camptothecin analogs including 7-Ethyl-10-hydroxycamptothecin (SN-38).

The present invention relates to a process for preparation of 2-Amino-5-hydroxy propiophenone, a key intermediate for the synthesis of camptothecin analogs including 7-Ethyl-10-hydroxycamptothecin (SN-38).

The objective of the present invention is to provide a method for producing a halogenated carbonyl safely and efficiently. The method for producing a halogenated carbonyl according to the present invention is characterized in comprising the step of applying ultrasound to a composition containing a C.sub.1-4 halogenated hydrocarbon having one or more halogeno groups selected from the group consisting of chloro, bromo and iodo in the presence of oxygen to decompose the C.sub.1-4 halogenated hydrocarbon.