Dibromo-2-butene

Ethyl a-(3-chloro-4-aminophenyl)-propionate hydrochloride 1,4-Dibromo-2-butene... 

Prepd from 1,4 Dibromo-2-butene and Ag-nitroform. It is an explosive of about the same sensitivity as PETN Refs 1) Beil, not found 2)uD.V. Sickman ... 

A conjugated double bond system undergoes 1,4-addition (Thiele s rule) for example, butadiene and an equimolar quantity of bromine yield 1,4-dibromo-2-butene (90%). On the other hand, chlorination of butadiene in the liquid or vapor phase furnishes about equal amounts of 1,2-and 1,4-addition products. Other polyfunctional compounds resulting from this method of preparation include dihalogenated acids, esters, aldehydes, and ketones. < The addition of bromine to unsaturated ethers yields dibromo ethers which are used as intermediates in the synthesis of olefins (method 21) and olefinic alcohols (method 99) ... 

C4H6Br2 trans-1,4-dibromo-2-butene 821-06-7 22.00 1.8895 2 3009 C4H604 dimethyl oxalate 553-90-2 60.00 1.1716 1... 

Use of chiral malonic esters in the reaction with 1,4-dibromo-2-butene to provide (+) 126. About 80% optical enrichment was achieved. 

Just prior to the 20th century Johannes Thiele (1865-1918) studied additions to conjugated dienes and discovered a tendency toward 1,4-addition, for example, the bromination of 1,3-butadiene to form 1,4-dibromo-2-butene (part A in the accompanying figure). There were apparently unsatisfied "residuai vaiences" on carbons 1 and 4 of 1,3-butadiene that rendered these positions reactive. On the other hand, the "residuai vaiences" on carbons 2 and 3 of 1,3-butadiene were adjacent and "saturated each other" rendering these positions unreactive. The Lewis-Langmuir eiectron-pair structures, deveioped during the... 

Radical cyclization of 482, prepared from the alkylation of MBH adducts 481 with 1,4-dibromo-2-butene in the presence of K2CO3, has been utilized to synthesize 3,3,4-trisubstituted pyrrolidines 483 (Scheme 4.145). As shown in... 

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