Disclosed is a method for synthesizing a sitagliptin intermediate, the method comprising: in the presence of hydrogen and a transition metal catalyst having a chiral phosphine ligand, subjecting a compound of formula II to an asymmetric reductive amination with ammonia or ammonium salt in a proper organic solvent under the condition of adding an acidic additive to produce a compound of formula I, wherein, an R- or S-configuration of a stereocenter is represented by *; the compound of formula I of R configuration can be used to prepare sitagliptin, and a reaction formula is as follows: R.sup.1 and R.sup.2 are each independently selected from hydrogen, C.sub.1-C.sub.12 linear or branched alkyl, C.sub.3-C.sub.12 cycloalkyl, C.sub.2-C.sub.12 alkenyl, C.sub.2-C.sub.12 alkynyl and C.sub.7-C.sub.12 arylalkyl. The method has a high yield and a high ee % value, a mild reaction condition and a low production cost, and is simple to operate, convenient to purify, environmental friendly and suitable for industrial production.

##STR00001##

A process for producing methanol includes combining a hydrogenation catalyst, hydrogen, and CO.sub.2 with a condensed phase solution comprising an amine under conditions effective to form methanol and water. A process for coproduction of methanol and a glycol includes combining an epoxide, a hydrogenation catalyst, hydrogen, and CO.sub.2 with a condensed phase solution comprising an amine under conditions effective to form methanol and a glycol.

A process for producing methanol includes combining a hydrogenation catalyst, hydrogen, and CO.sub.2 with a condensed phase solution comprising an amine under conditions effective to form methanol and water. A process for coproduction of methanol and a glycol includes combining an epoxide, a hydrogenation catalyst, hydrogen, and CO.sub.2 with a condensed phase solution comprising an amine under conditions effective to form methanol and a glycol.

A process for producing methanol includes combining a hydrogenation catalyst, hydrogen, and CO.sub.2 with a condensed phase solution comprising an amine under conditions effective to form methanol and water. A process for coproduction of methanol and a glycol includes combining an epoxide, a hydrogenation catalyst, hydrogen, and CO.sub.2 with a condensed phase solution comprising an amine under conditions effective to form methanol and a glycol.

A process for producing methanol includes combining a hydrogenation catalyst, hydrogen, and CO.sub.2 with a condensed phase solution comprising an amine under conditions effective to form methanol and water. A process for coproduction of methanol and a glycol includes combining an epoxide, a hydrogenation catalyst, hydrogen, and CO.sub.2 with a condensed phase solution comprising an amine under conditions effective to form methanol and a glycol.

Various embodiments include a process for converting a starting material mixture comprising carbon dioxide and hydrogen into methanol and water. The method may include: providing a catalyst to a reactor; feeding carbon dioxide and hydrogen into the reactor, at a first pressure and a first temperature; feeding a first liquid component into the reactor at a second temperature lower than the first temperature; converting the carbon dioxide and hydrogen into methanol and water; removing the methanol from a gas phase in at least one liquid phase comprising the first component and the water; and discharging a first liquid material stream comprising the first component, methanol, and water from the reactor. At the first temperature and the first pressure the methanol is in a gaseous state and the first component and the water are in a liquid state.

Various embodiments include a process for converting a starting material mixture comprising carbon dioxide and hydrogen into methanol and water. The method may include: providing a catalyst to a reactor; feeding carbon dioxide and hydrogen into the reactor, at a first pressure and a first temperature; feeding a first liquid component into the reactor at a second temperature lower than the first temperature; converting the carbon dioxide and hydrogen into methanol and water; removing the methanol from a gas phase in at least one liquid phase comprising the first component and the water; and discharging a first liquid material stream comprising the first component, methanol, and water from the reactor. At the first temperature and the first pressure the methanol is in a gaseous state and the first component and the water are in a liquid state.

Provided is a method which is for producing methanol and which achieves high catalyst stability over time. This method for producing methanol includes the step of bringing a raw material gas into contact with a catalyst to obtain methanol, the raw material gas containing a carbon oxide and hydrogen, the catalyst containing (i) copper and zinc at a molar ratio of the zinc relative to the copper (Zn/Cu) of 0.3 to 0.45, and (ii) an alkali metal in an amount of 0% by mass to 0.05% by mass.

Provided is a method which is for producing methanol and which achieves high catalyst stability over time. This method for producing methanol includes the step of bringing a raw material gas into contact with a catalyst to obtain methanol, the raw material gas containing a carbon oxide and hydrogen, the catalyst containing (i) copper and zinc at a molar ratio of the zinc relative to the copper (Zn/Cu) of 0.3 to 0.45, and (ii) an alkali metal in an amount of 0% by mass to 0.05% by mass.