of about 1 1 of sitagliptin base to dibenzoyl d tartaric acid after the addition of the acid in this process or any process for the preparation of any of the sitagliptin dibenzoyl tartrate polymorphs disclosed herein the obtained mixture can be heated to a temperature from about 40 u00b0 c to about 60 u00b0 c or from about 45 u00b0 c to about 55 u00b0 c for example about 50 u00b0 c heating can be maintained for about 1 to about 10 hours or from about 1 to about 4 hours for example for about 2 hours afterward the mixture can be cooled to a temperature from about 0 u00b0 c to about room temperature or from about 10 u00b0 c to about room temperature or about room temperature for example overnight before collecting the obtained precipitate the obtained precipitate can further be dried hereinafter is described a crystalline sitagliptin dibenzoyl tartrate designated form d2 characterized by data selected from a powder xrd pattern with peaks at 6 9 u00b0 11 9 u00b0 15 9 u00b0 and 17 9 u00b0 u00b1 0 2 u00b0 2 u03b8 a powder xrd pattern as shown in fig2 b and combinations thereof sitagliptin dibenzoyl tartrate form d2 can be also characterized by a powder xrd pattern with peaks at 5 0 u00b0 6 9 u00b0 10 7 u00b0 11 9 u00b0 14 5 u00b0 15 9 u00b0 17 9 u00b0 19 0 u00b0 22 6 u00b0 and 23 8 u00b0 u00b1 0 2 u00b0 2 u03b8 sitagliptin dibenzoyl tartrate form d2 can be prepared by a process comprising forming a mixture e g a.