3234-02-4Relevant articles and documents
A 2, 3 - dibromo - 1, 4 - butylene diol synthesis method
-
Paragraph 0027-0043, (2019/07/01)
The invention discloses a 2, 3 - dibromo - 1, 4 - butylene diol synthesis method, solves the technical 2, 3 - dibromo - 1, 4 - butylene glycol of complex synthesis method, harsh reaction conditions not security, and the parameter is not easy to control, the production cost is high, poor quality of the products, the technical problem to limit its use. The invention discloses a 2, 3 - dibromo - 1, 4 - butylene diol synthesis method, comprises the following steps: 1) in dichloromethane solvent, after adding catalyst ammonium bromide, [...] while stirring, to obtain the brominating agent ammonium bromide complex bromide; 2) in dichloromethane solvent, adding butynediol with the step 1) of ammonium bromide complex prepared by brominating electrophilic addition reaction of bromide occurs, generating a 2, 3 - dibromo - 1, 4 - butylene glycol; water washing, cooling, so that the 2, 3 - dibromo - 1, 4 - butylene glycol crystallization, after filtering, a 2, 3 - dibromo - 1, 4 - butylene glycol crude; 3) purification of 2, 3 - dibromo - 1, 4 - butylene glycol crude product. The invention can be widely applied to the technical field of chemical synthesis.
Hexamethonium bis(tribromide) (HMBTB) a recyclable and high bromine containing reagent
Paul, Bappi,Bhuyan, Bishal,Purkayastha, Debraj D.,Dhar, Siddhartha S.,Patel, Bhisma K.
, p. 5646 - 5650 (2015/09/21)
A recyclable and high bromine containing di-(tribromide) reagent, hexamethonium bis(tribromide) (HMBTB) has been synthesized and utilized for the bromination of various organic substrates. The spent reagent hexamethonium bromide (HMB) can be effectively recycled by regenerating and reusing it without significant loss of activity. The crystalline and stable bis(tribromide) is an effective storehouse of very high percentage of active bromine requiring just half an equivalent of it for complete bromination. Both the Br3- moieties in HMBTB are nearly linear with Br-Br-Br angle of 179.55°.
Regioselective bromination of organic substrates by tetrabutylammonium bromide promoted by V2O5-H2O2: An environmentally favorable synthetic protocol
Bora, Upasana,Bose, Gopal,Chaudhuri, Mihir K.,Dhar, Siddhartha S.,Gopinath, Rangam,Khan, Abu T.,Patel, Bhisma K.
, p. 247 - 249 (2007/10/03)
(matrix presented) Vanadium pentoxide very effectively promotes the bromination of organic substrates, including selective bromination of some aromatics, by tetrabutylammonium bromide in the presence of hydrogen peroxide; mild conditions, high selectivity, yield, and reaction rate, and redundancy of bromine and hydrobromic acid are some of the major advantages of the synthetic protocol.