Category: 657428-42-7

Some common heterocyclic compound, 657428-42-7, name is tert-Butyl 4,6-dihydropyrrolo[3,4-c]pyrazole-5(1H)-carboxylate, molecular formula is C10H15N3O2, 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. category: pyrazoles-derivatives

Intermediate 5; 2-(Methylsulfonyl)-2,4,5,6-tetrahydropyrrolo[3,4-c]pyrazole; Step A: tert-Butyl 1-(methylsulfonyl)]-4,6-dihydropyrrolo[3,4-c]pyrazole-5(1H)-carboxylate (A) and tent-butyl 2-(methylsulfonyl)]-2,6-dihydropyrrolo[3,4-c]pyrazole-5(4H)-carboxylate (B); A suspension of N-Boc-pyrazolopyrrolidine (Intermediate 3, Step B) (27.16 g, 130 mmol) in anhydrous acetonitrile (1.0 L) was charged in a 2.0 L three-neck flask fitted with a thermometer and an addition funnel and then treated with sodium hydride (60% dispersion in oil, 6.23 g, 156 mmol) while under nitrogen atmosphere in one portion. The reaction mixture was stirred at room temperature for 2 h. The resulting white suspension was then cooled in an ice bath and methanesulfonyl chloride (25.2 mL, 324 mmol) was slowly added via addition funnel The ice bath was then removed and the mixture was stirred 1 h at room temperature. The reaction mixture was quenched with water (500 mL) and the layers were separated. The aqueous layer was then extracted with 2×500 mL of dichloromethane. The combined organic layers were dried over sodium sulfate and concentrated under reduced pressure to give a mixture of products A and B as colorless syrups. NMR in CD3OD indicated a 1:1 mixture of two products, in which the proton on the pyrazole ring in product A appeared at 7.70 ppm while the proton in product B appeared at 7.95 pm. LC-MS: 288.08 (M+1).

These compound has a wide range of applications. It is believed that with the continuous development of the source of the synthetic route 657428-42-7, its application will become more common.

Reference:
Patent; Biftu, Tesfaye; Chen, Ping; Cox, Jason M.; Weber, Ann E.; US2010/120863; (2010); A1;,
Pyrazole – Wikipedia,
Pyrazoles – an overview | ScienceDirect Topics

Application of 657428-42-7, As we all know, there are many different methods for the synthesis of a compound, and people can choose the synthesis method that suits their own laboratory according to the actual situation. 657428-42-7 name is tert-Butyl 4,6-dihydropyrrolo[3,4-c]pyrazole-5(1H)-carboxylate, This compound is widely used in many fields, so it is necessary to find a new synthetic route. The downstream synthesis method of this compound is introduced below.

Step D: tert-Butyl 2-(methylsulfonyl)-2,6-dihydropyrrolo[3,4-c]pyrazole-5(4H)-carboxylate A solution of tert-butyl 4,6-dihydropyrrolo[3,4-c]pyrazole-5(1H)-carboxylate (30.0 kg, 143 mol) in 2-methyltetrahydrofuran (384 mg) was vacuum purged with nitrogen back-fill three times. The, triethylamine (25.0 kg, 247 mol) was added and the batch cooled to -10-5 C. Then, methanesulfonyl chloride (21.4 kg, 187 mol) was slowly added over 2 h. After stirring for 1 h at room temperature, water (150 kg) was added drop-wise at 5-15 C. This was followed by addition of 1N HCl solution until the pH was 7. The resulting layers were separated and the aqueous extracted with 2-methyltetrahydrofuran (106 kg). The combined organics were washed with saturated brine (2*150 kg), dried with Na2SO4, filtered, and concentrated to 60-90 L. The resulting crude was dissolved in 2-methyltetrahydrofuran (381 kg) and charged with a solution of potassium tert-butoxide in THF (805 g in 6.6 kg THF). After stirring 1 h at room temperature under nitrogen, more potassium tert-butoxide in THF (329 g in 3.0 kg THF) was added and stirred for 1 h. Analytical analysis indicates that tert-butyl 2-(methylsulfonyl)-2,6-dihydropyrrolo[3,4-c]pyrazole-5(4H)-carboxylate is the major regioisomer, so saturated brine (154 kg) was then added. After brief agitation, the layers are separated and the oragnics are washed with saturated brine (2*155 kg). The combined aqueous waste layers were then extracted with 2-methyltetrahydrofuran (103 kg). The combined organics were treated with activated carbon (8.75 kg), filtered, and dried with Na2SO4. This was then filtered and concentrated to 60-90 L. This slurry was then heated to dissolve solids at 40-50 C. and n-heptane was added (34 kg). After cooling to room temperature for 2-4 h, n-heptane (156 kg) was added and the slurry was then aged for 2-4 h at 0-5 C. The slurry was filtered and the cake washed with n-heptane. The solids were dried under vacuum at 45-55 C. to give tert-butyl 2-(methylsulfonyl)-2,6-dihydropyrrolo[3,4-c]pyrazole-5(4H)-carboxylate.

At the same time, in my other blogs, there are other synthetic methods of this type of compound, tert-Butyl 4,6-dihydropyrrolo[3,4-c]pyrazole-5(1H)-carboxylate, and friends who are interested can also refer to it.

Reference:
Patent; Merck Sharp & Dohme Corp; Merck Sharp & Dohme Ltd.; Arroyo, Itzia Z.; Krueger, Davida; Chen, Ping; Moment, Aaron J.; Biftu, Tesfaye; Sheen, Faye; Zhang, Yanfeng; US9181262; (2015); B2;,
Pyrazole – Wikipedia,
Pyrazoles – an overview | ScienceDirect Topics