(4-BROMOBENZYL)TRIPHENYLPHOSPHONIUM BROMIDE

cream crystalline powder

4-Bromobenzyl bromide (50 g, 200 mmol, 1.0 equiv), triphenylphosphine (57 g, 220mmol, 1.1 equiv), in CHC13 (400 mL, 0.5 M) was heated under reflux 4 h. The solution was cooled to room temperature and the phosphonium was crunched with Et20 (1.5 L). The crude product was diluted with CH2C12 (300 mL) and was crunched with Et20 (1.5 L) was filtered under Buchner and washed with Et20 (500 mL) to afford target compound (44) as a white solid (123 g, quant. yield).Multi function cap round bottom 1-bromo-4-(bromomethyl) Benzene to 500 ml (14.0 g, 0.056 mol), Triphenylphosphine (16.162 g, 0.062 mol) has added. Herein, as a solvent at room temperature of 58 ml Acetone adaptation stirring time doesn't have any error frames, 12. 28.4 g is obtained complete after title compound. (99.0percent yield).In a two-necked round bottom fask a mixture of 1-bromo-4-(bromomethyl)benzene (10g, 40mmol), triphenylphosphine (11.5g, 44mmol, 1.1 eq) inacetone (42mL) was stirred atroom temperature under N2 atmospherefor 12h. The reactionmixturewasthen ltered andthewhitesolidswerecollectedwashedwithacetonebeforedrying invacuo(20.3g, 99percent).(i) [Step 1; Synthesis of 4-bromobenzyl triphenylphosphonium bromide] First, 25.2 g (101 mmol) of 4-bromobenzyl bromide and 100 mL of acetone were put into a 200 mL conical flask, and 29.1 g (111 mmol) of triphenylphosphine was added thereto. The mixture was stirred for 23 hours at room temperature. After the reaction, a precipitate in the reaction mixture was collected by suction filtration to give 50.5 g of a white powdered solid of (4-bromobenzyl)triphenylphosphoniumbromide (yield: 97.6percent).First, 25.36 g (101.5 mmol) of 4-bromobenzylbromide and 100 mL of acetone were put in a 100 mL conical flask, and 29.28 g (111.6 mmol) of triphenylphosphine was added thereto. The mixture was stirred for 24 hours at room temperature. After the reaction, a precipitate in the reaction mixture was collected by suction filtration, and 50 g of a white powdered solid of 4-bromobenzyltriphenylphosphoniumbromide was obtained in a yield of 96percent.A 200 mL conical flask was charged with 25.36 g (101.5 mmol) of 4-bromobenzyl bromide and 100 mL of acetone. 29.28 g (111.6 mmol) of triphenylphosphine was added thereto to be stirred for about 24 hours at room temperature. After the reaction, precipitate in the reaction mixture was collected by suction filtration to obtain 50 g of white powder of 4-bromobenzyl triphenylphosphonium bromide in a yield of 96percent. A synthesis scheme of 4-bromobenzyl triphenylphosphonium bromide is shown below.A solution of 4-bromo benzyl bromide (10.0 g, 40.0 mmol) and PPhGeneral procedure: Triphenylphosphine (5 mmol) was added to a solution of 4-substituted-benzyl halide (5 mmol) in toluene (50 mL). The mixture was heated to reflux for 6 h and then cooled to room temperature. The precipitate was collected, recrystallized from ethanol to give the products.General procedure: To a solution of benzylbromide (33 mmol) in toluene (20 mL) was added a solution of triphenylphosphine (36.3 mmol) in toluene (25 mL). After being heated at reflux for 5 h, the reaction mixture was cooled at room temperature and a first crop of product was collected by filtration. The filtrate was then refluxed for additional 5 h and a second crop of product precipitated (10-20percent). The collected crops were crystallized from ethanol to give pure phosphonium bromide in high yield.4-Bromobenzyl bromide (7.07 g, 28.30 mmol) and triphenylphosphine (7.42 g, 28.30 mmol) weresuspended in 50 mL toluene and the solution was refluxed overnight. During reaction, a whiteprecipitate formed. It was filtered off, washed several times with ether and dried under vacuum(13.42 g, 93percent yield).Intermediate 2 (4^Bromobenzyl)(triphenyl)phosphonium bromide To a stirred solution of 1 -bromo-4-(bromomethyl)benzene (8g, 32mmol) in toluene (160 ml) was added triphenylphosphine (8.4g, 32mmol). The reaction was stirred at 120°C under an atmoshpere of nitrogen for 17 hours after which time a white precipitate had formed. The reaction was then cooled to room temperature and the solid was collected by filtration, washing with a minimum amount of cold toluene to give (4- bromobenzyl)(triphenyl)phosphonium bromide as a white solid (15.4 g, 89 percent) lH NMR (400 MHz, DMSO-c/6) δ 7.85 - 8.01 (m, 2 H), 7.57 - 7.84 (m, 8 H), 7.33 - 7.55 (m, 1 H), 6.79 - 7.02 (m, 1 H), 5.04 - 5.28 (m, 2 H) MS ES+ 433, 435

Molecular Weight:512.2
Hydrogen Bond Acceptor Count:1
Rotatable Bond Count:5
Exact Mass:511.97271
Monoisotopic Mass:509.97476
Heavy Atom Count:28
Complexity:378
Covalently-Bonded Unit Count:2
Compound Is Canonicalized:Yes