The Use of Benzylsulfonyl Chloride in Peptide Syntheses^1,2

Selenium sulfur dihalides, ChnX2 (n = 1, 2, 3; Ch = Se, S; X = Br, Cl). Raman and 77Se NMR spectroscopic characterization

“…The greater width at half-height of the diselenium dihalide signals indicates more rapid halide exchange for these compounds than for the selenium sulfur dihalides (13) and, by extension of this trend, than for the disulfur dihalides. This is expected, as a result of the weaker halogen bonding to Se (D (SeCl) = 243 kJ mol-') than to S (D(SC1) = 272 kJ mol-I) (20).…”

Ecofriendly Synthesis in Aqueous Medium: An Expeditious Approach to New N,N-Diethyl Amide Bearing Benzenemethanesulfonamides

“…First and foremost, the coupling of benzenemethanesulfonyl chloride with eleven different amino acids resulted in the formation of the corresponding benzenemethanesulfonamide (1a-k) as shown in Scheme (1). Although, some of these benzenemethanesulfonamides (1a, 1c and 1d) had been reported earlier in low yields [40], that is why it is very crucial to explore various reaction conditions for effective optimization study in order to establish another method to obtain these benzenemethanesulfonamides in high and encouraging yields without posing any threat to the environment. It is interesting to note that the N,N-diethyl amide bearing sulfonamides (2a-k) have not been reported before, to the best of our knowledge.…”

“…This successfully established procedure was then repeated for ten other amino acids to get the corresponding benzenemethanesulfonamides (1b-k) in good to excellent yields. Difficulty connected with the poor reactivity of the benzenemethanesulfonyl chloride was overcome by increasing the duration of stirring at room temperature to 48 h. The efficiency of the method used here-in (X) over the earlier reported approach (Y) [40] was evaluated via comparative study as shown in Table 2. For instance, the synthesis of (1a) earlier reported was achieved in 22% yield whereas excellent augmentation was experienced in our study here-in, which afforded (1a) at 92% yield.…”

“…In addition, numerous reports have focused on benzenesulfonyl chloride and ptoluenesulfonyl chloride in the synthesis of bioactive sulfonamides [37][38][39]. Also, reaction of benzyl sulfonyl chloride with some amino acids had been reported to give sulfonamides but in low to poor yields [40]. This incident of poor yields calls for a facile approach to preparing sulfonamide in improved yields.…”

Protection Reactions

“…of Nbs-Cl in a mixture of 1 : 1 dioxane and 1 M NaOH. This is a modified procedure originally employed for the preparation of benzylsulfonyl amino acids [258]. H-a-Me-Ser-OMeÁHCl (2.96 g, 17.5 mmol) was dissolved in THF/DMSO (80 ml/ 20 ml), and NaHCO 3 (8.82 g, 105.0 mmol) and BzlBr (8.36 ml, 70.3 mmol) were added.…”