The present invention provides a process for the preparation of crystalline anhydrous compound of Formula (X), Further, the present invention relates to the use of compound of Formula (X) preparation of Raltegravir (I) or its pharmaceutically acceptable salt thereof.

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The invention provides methods of synthesizing a viral protease inhibitor in high yield, without using expensive catalysts or challenging reaction conditions.

The invention provides methods of synthesizing a viral protease inhibitor in high yield, without using expensive catalysts or challenging reaction conditions.

The invention provides methods of synthesizing a viral protease inhibitor in high yield, without using expensive catalysts or challenging reaction conditions.

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##

Provided herein are methods of making the compound of Formula I: ##STR00001##
and certain intermediates involved in such process.

Provided herein are methods of making the compound of Formula I: ##STR00001##
and certain intermediates involved in such process.

Provided herein are methods of making the compound of Formula I: ##STR00001##
and certain intermediates involved in such process.

The present invention relates to a process for the preparation of a compound of formula (A), Further, the present invention relates to the respective compound (A) as such and to its use in the preparation of antifungal agent.

##STR00001##

The present invention relates to a process for the preparation of a compound of formula (A), Further, the present invention relates to the respective compound (A) as such and to its use in the preparation of antifungal agent.

##STR00001##