3-bromopropane-1,2-diol

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: Triethylamine (6 g, 8.2 ml, 58 mmoles) was added to L-cysteine hydrochloride (3 g, 19 mmole) and 3-bromo-propan-1,2-diol (4.2 g, 2.36 ml, 27 mmole) in water and the homogeneous solution kept at room temperature for 3 days. The solution was reduced in vacuo at 40° C. to a white residue which was boiled with methanol (100 ml), centrifuged and the residue dissolved in water (5 ml). This aqueous solution was added to acetone (300 ml) and the precipitate isolated by centrifugation. The precipitate was purified by several precipitations from water with acetone to give S-(2,3-dihydroxypropyl)cysteine as a white amorphous powder (2.4 g, 12.3 mmol, 64.7%). was reduced in vacuo at 40° C. to a white residue which the precipitate isolated by centrifugation The precipitate was purified by several precipitations from water with acetone

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: N-acetyl-3-acetoxymethyl-5-(2,3-diacetoxypropylaminocarbonyl)-2,4,6-triiodoaniline (1.0 g, 1.27 mmol) was suspended in a mixture of methanol (6 ml) and water (30 ml) and pH was adjusted to 12.0 using a 2 M aqueous solution of NaOH. After stirring for 1 h, 1-bromo-2,3-propanediol (0.99 g, 6.4 mmol) was added and the pH was adjusted to 11.6 using a 2 M aqueous solution of HCl. 1-Bromo-2,3-propanediol (0.99 g, 6.4 mmol) was again added after 16 and 18 h and after 24 h, pH was adjusted to 6.5 using a 2 M aqueous solution of HCl. After evaporation, the residue was purified by preparative HPLC. Yield: 0.373 g (40%). after 24 h After evaporation the residue was purified by preparative HPLC

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: To a solution of diethylphosphonoacetaldehyde diethylacetal (15.00 g, 59.0 mmol) and 3-bromo-1,2-propanediol (11.00 g, 71.0 mmol, 1.2 eq.) in toluene (60 mL) was added pTSA (few cristals). The mixture was stirred at reflux for 72 hr and was cooled to room temperature. A saturated solution of sodium bicarbonate was added and the aqueous phase was extracted with dichloromethane. The organic phase was dried over anhydrous sodium sulphate and evaporated under reduced pressure. The crude material was pure by TLC and NMR and gave 17.93 g of the compound in a 96% yield. at reflux for 72 hr the aqueous phase was extracted with dichloromethane The organic phase was dried over anhydrous sodium sulphate evaporated under reduced pressure

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: To a solution of 3-bromo-1,2-propanediol (6.0 g, 38.7 mmol) in benzene (90 mL) was added trimethylorthoformate (4.23 mL, 38.7 mmol, 1 eq.) and p-toluenesulfonic acid (pTSA, few crystals). The mixture was stirred for 20 hr at 85°-90° C., then cooled to room temperature and benzene was removed under reduced pressure. The crude material was obtained in 96% yield (7.26 g) as a mixture of cis and trans isomers in a 1:1 ratio. benzene was removed under reduced pressure

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: An acetone solution of bromomethyl ethylene glycol is refluxed for 24 hours in the presence of anhydrous magnesium sulfate. The cooled reaction mixture is filtered and the solvent is removed to provide a residual crude product. The cooled reaction mixture is filtered the solvent is removed

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: To a stirred solution of 3-bromo-1,2-propanediol (10.85 g, 70 mmole), N-CBz-L-valine (10.05 g, 40 mmole) and DMAP (0.49 g, 4 mmol) in 250 ml dichloromethane was added dropwise a solution of DCC (9.1 g, 44 mmol) in 50 ml dichloromethane at about 10° C. The mixture was stirred for two days at room temperature and then cooled to 5° C. The urethane was filtered and the solution was evaporated under reduced pressure. The product was isolated by silica gel column chromatography. Yield: 8 g cooled to 5° C The urethane was filtered the solution was evaporated under reduced pressure The product was isolated by silica gel column chromatography