- Pyrazolo [3, 4 - d] pyrimidines of the synthesis process
-
The invention relates to a synthesis process of pyrazolo[3,4-d]pyrimidine compounds. The synthesis process comprises the following steps: (1) adding 3-aminopyrazole-4-carboxamide hemisulfate and methanamide into a reaction kettle, adjusting the pH value to 1.6-3.8, heating to react, and cooling to the room temperature; (2) standing the product obtained in the step (1) at 5-10 DEG C and crystallizing; (3) filtering, transferring rough crystals into a pulping kettle, adding purified water, pulping, and washing; and (4) filtering again, discarding filtrate, washing filter cake with purified water until the pH value of eluate is higher than or equal to 6, and drying to obtain white 4-hydroxypyrazolo[3,4-d]pyrimidine. According to the synthesis process, synthesis operation steps and difficulty are simplified, the cost of inert gas shielding is avoided; and meanwhile, the synthesis process is applicable to the synthesis of 4-mercaptopyrazolo[3,4-d]pyrimidine, so that the synthesis process is applicable to the large-scale industrial synthesis application.
- -
-
Paragraph 0016; 0017; 0019; 0020; 0021; 0020; 0021-0055
(2017/08/24)
-
- Method of preparing 3-morpholino-2-cyanoacrylamide
-
A compound STR1 where R' is hydrogen or lower alkyl, the compound being usable as an intermediate in the preparation of 4-hydroxypyrazolo [3,4-d]pyrimidine (Allopurinol) and its useful relatives. A method of preparing STR2 which comprises reacting R'C(OR)3, morpholine and cyanoacetamide where R' is hydrogen or lower alkyl and R' is lower alkyl.
- -
-
-