These common heterocyclic compound, 718632-46-3, name is 5-tert-Butyl 2-ethyl 3-amino-6,6-dimethylpyrrolo[3,4-c]pyrazole-2,5(4H,6H)-dicarboxylate, its traditional synthetic route has been very mature, but the traditional synthetic route has various shortcomings, such as complicated route, low yield, poor purity, etc, below Introduce a new synthetic route. Quality Control of 5-tert-Butyl 2-ethyl 3-amino-6,6-dimethylpyrrolo[3,4-c]pyrazole-2,5(4H,6H)-dicarboxylate
To a solution of 9.70 g (61.3 mmol) of 1-(trimeth- ylsilyl)cyclopropanecarboxylic acid [synthesized according to the method described in J. Org. Chem., 1982(47) 5, 893-895] in 120 ml of dehydrated dichloromethane, 6.60 ml (76.9 mmol) of oxalyl chloride and 0.25 ml (3.2 mmol) of dehydrated DMF were added in this order at 00 C. in a nitrogen atmosphere and reacted at 00 C. for 2.5 hours with stirring. After completion of the reaction, the reaction solution was concentrated under reduced pressure and dried under reduced pressure. A solution of the obtained concentration residue in 30 ml of dehydrated dichloromethane was added to a solution of 19.0 ml (109 mmol) of DIPEA and 9.94 g (30.6 mmol) of 5-tert-butyl 2-ethyl 3-amino-6,6- dimethylpyrrolo[3,4-c]pyrazole-2,5(4H,6H)-dicarboxylate[synthesized according to the method described in Journal of Medicinal Chemistry 2012, 55 (10), 4728-4739] in 170 ml of dehydrated dichioromethane at 00 C. in a nitrogen atmosphere and reacted at 00 C. for 24 hours with stirring. After completion of the reaction, a saturated aqueous solution of sodium bicarbonate was added to the reaction solution and stirred, followed by extraction once with dichloromethane and twice with ethyl acetate. The whole organic layer thus obtained was dried over anhydrous magnesium sulfate, then filtered, and concentrated under reduced pressure. The obtained concentration residue was subjected to preparative column chromatography (apparatus 2, silica gel, elution solvent: n-hexane:ethyl acetate=90: 10-70:30 (V/V)), and a fraction containing 5-tert-butyl 2-ethyl 6,6- dimethyl-3-[1 -(trimethylsilyl)cyclopropanecarboxamido]pyrrolo[3,4-c]pyrazole-2,5(4H,6H)-dicarboxylate was concentrated under reduced pressure. The concentration residue of the fraction containing impurities was subjected again to preparative column chromatography (apparatus 2, silica gel, elution solvent: n-hexane: ethyl acetate=90: 1 0-75 :25 (V/V)), combined with the preliminarily obtained fraction, concentrated under reduced pressure, and dried under reduced pressure.
The synthetic route of 5-tert-Butyl 2-ethyl 3-amino-6,6-dimethylpyrrolo[3,4-c]pyrazole-2,5(4H,6H)-dicarboxylate has been constantly updated, and we look forward to future research findings.
Reference:
Patent; UBE INDUSTRIES, LTD.; IWASE, Noriaki; AGA, Yasuhiro; USHIYAMA, Shigeru; KONO, Shigeyuki; SUNAMOTO, Hidetoshi; MATSUSHITA, Takashi; OGI, Sayaka; UMEZAKI, Satoshi; KOJIMA, Masahiro; ONUMA, Kazuhiro; SHIRAISHI, Yusuke; OKUDO, Makoto; KIMURA, Tomio; (165 pag.)US2018/186818; (2018); A1;,
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