A preparation method for methylphenol and homologue. Under the conditions of reaction temperature of 150-350 C. and reaction pressure of 1-50 atm, a mixed material of methanol, ethanol and acetone is fed into a reactor containing a catalyst by a carrier gas to produce methylphenol through coupling-aromatization reaction. The method provides a reaction path for directly producing methylphenol and homologue from low carbon micromolecular alcohol and ketone through coupling-aromatization reaction, the maximum selectivity of total cresol is 34.0%, and the selectivity of 2,3,6-trimethylphenol is up to 7.1%. The by-product hydrogen of the reaction path can be used as a chemical material. Other by-products such as high carbon alcohol and ketone whose melting and boiling points are quite different from those of methylphenol and which are easy to be separated by rectification can be used as fuel additives to partially replace petroleum-based products.

An object of the present invention is to provide a method for selectively producing a hydroxycarboxylic acid ester, the method including reducing a dicarboxylic acid monoester by means of a heterogeneous reaction. According to a method for producing a hydroxycarboxylic acid ester in an embodiment of the present invention, a hydroxycarboxylic acid ester represented by Formula (2) is produced by reducing a substrate dicarboxylic acid monoester represented by Formula (1) in the presence of a catalyst.

The catalyst comprises: metal species including M.sub.1 and M.sub.2; and a support supporting the metal species, and wherein M.sub.1 is rhodium, platinum, ruthenium, iridium or palladium; M.sub.2 is tin, vanadium, molybdenum, tungsten or rhenium; and the support is hydroxyapatite, fluorapatite, or hydrotalcite.

##STR00001##

A catalyst for dehydration reaction of hydroxypropionic acid and derivatives thereof, and a preparation method thereof. The catalyst includes a molded body in which primary particles of hydroxyapatite are aggregated, wherein a volume average particle size of the primary particles is 15 m to 150 m, and a P value represented by the following Equation 1 is 3.5 to 19:

[00001]$\begin{array}{cc}P=A*B/C& \left[\mathrm{Equation}1\right]\end{array}$

wherein in Equation 1. A represents the volume average particle size (m) value of powder, B represents a crush strength (N) value, and C represents a specific surface area (m.sup.2/g) value. The catalyst has very excellent life characteristics while exhibiting a high reaction yield and selectivity.