Hydroxyethyl Phenyl Sulfone

InChIKey = PQVYYVANSPZIKE-UHFFFAOYAD (protection of carboxylic aclds preparation of a chloroformate 

Handling, Storage, and Precautions irritant, handle with gloves in a fume hood. 

Preparation of a Chloroformate Reagent (6) for the Protection of Alcohols and Amines. Reaction of (1) with phosgene affords the chloroformate (6) (eq 3), a useful reagent for the protection of alcohols and amines.  

Chloroformate (6) reacts with alcohols in pyridine at room temperature to afford carbonates (7). The 2-phenylsulfonylethoxycarbonyl (PSEC) group is stable to the conditions required to cleave tetrahydropyranyl (THP) ethers, 2-trimethylsilylethoxy carbonates (TEOC), and levulinate and benzoate esters. The alcohol can be r enerated when desired by treatment with triethylamine in p3nidlne (eq 4). 

Protection of Carboxylic Acids. 2 -Hydroxyethyl phenyl sulfone (1) Is a useful reagent for the protection of carboxylic acids. Thus, treatment of the protected muramic add derivative (2) with (1) and DCC afforded the 2 (phenylsulfonyl)ethyl ester (3) in excellent yield (eq 1).  

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In one example of this type of cyclization aminoalcohol, 288, which was obtained by conjugate addition of racemic 2-(2-hydroxyethyl)piperidine to allyl phenyl sulfone, was converted into the corresponding chloride and cyclized in the presence of LDA to give 289 as a single diastereomer (Scheme 63) <2003JOC9389>. In a related approach, the primary alcohol group was activated for a similar cyclization by transformation into a mesylate <20010L2957>. 

DI-f e/t-BUTYL-4-HYDROXYPHENYL ) PROPIONOXY] ETHYL 4-AZI-dosulfonylcarbanilate (DTBPSC). 3- (3,5-Di-terf-butyl-4-hydroxy-phenyl)propionyl chloride (20 g, 0.7 mol) (20) and 200 mL of dry DMF containing a few drops of pyridine were placed in a 500-mL flat-bottomed flask. The solution was stirred at room temperature as 21 g (0.7 mol) of 2-hydroxyethyl-4-azidosulfonylcarbanilate (15) dissolved in 150 mL of DMF were added. After stirring at room temperature, the DMF solution was poured into ice water and the solid was collected and dried to yield 22 g (58%) of product (mp 70-75°C). It decomposed at 175°C with evolution of nitrogen. The ir spectrum contained absorption bands at 3420 cm 1 (NH), 2120 cm 1 (azide), 1735 cm"1 (ester carbonyl), 1725 cm"1 (carbamate), and 1165 cm 1 (sulfone). 

Chlorosulfonic acid may also be used in the manufacture of (amino-alkyl)-phenyl reactive dyes thus the hydroxyethyl sulfone 44 was reacted with chlorosulfonic acid to yield the sulfate 45. The latter was subsequently condensed with cyanuric chloride 46 and the azo-5-pyrazolone 47 to yield the golden-yellow dye 48 (Scheme 10). ... 

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