Researchers who often do experiments know that organic synthesis is a process of preparing more complex target molecules from simple raw materials through one or more chemical reactions. Generally, it requires fewer steps, and cheap raw materials. 5414-21-1, name is 5-Bromovaleronitrile, A new synthetic method of this compound is introduced below., Formula: C5H8BrN
Sodium hydride paste (6.16 g. of 61% w/w suspension in liquid paraffin) was added portionwise over 30 minutes to a solution of 3-nitropyrazole (17.4 g.) in dry DMF (150 ml.) with external ice cooling to maintain the temperature at 20-30. The mixture was stirred for 45 minutes and to the almost clear solution was added 5-bromovaleronitrile (25 g.) over 30 minutes, at 25-30, and the mixture was stirred for 4 hours. Water (450 ml.) and EtOAc (450 ml.) was added and the upper layer was separated, dried (MgSO4) and evaporated in vacuo to an oil which was a mixture of 5-(3-nitropyrazol-1-yl)valeronitrile and 5-(5-nitropyrazol-1-yl)valeronitrile. The oil was divided into two 15 g. portions which were fractionated on a silica column (3.5 cm diameter*100 cm long) eluted at 2 atmospheres by EtOAc/60-80 petroluem ether (3:7 v/v). The 1.5 isomer was eluted first followed by the 1:3 isomer. The 5-(3-nitropyrazol-1-yl)valeronitrile had m.p. 32-33. To a solution of 5-(3-nitropyrazol-1-yl)valeronitrile (9.16 g.) in dry tetrahydrofuran (200 ml.) was added 5% w/w palladium on carbon (1.8 g.). The mixture was stirred at 20 under an atmosphere of hydrogen. 3.2 Liters of hydrogen were absorbed over 4 hours. The catalyst was filtered off and the filtrate was evaporated in vacuo to give 5-(3-aminopyrazol-1-yl)valeronitrile as an oil.
The basis of chemical reaction formula synthesis, the synthesis route is composed of some specific reactions and combined according to certain logical thinking. We look forward to the emergence of more reaction modes in the future.
Reference:
Patent; Imperial Chemical Industries PLC; US4447441; (1984); A;,
Nitrile – Wikipedia,
Nitriles – Chemistry LibreTexts