Solvent-Free C-S Bond Formation under Microwave Irradiation

Crystalline /V-vinylization 1 (200 mg, 1.16 mmol) was exposed to 10 mmol metlianethiol gas (0.9 bar) at a vacuum line for 21 h. The products 2 and 3 were isolated by preparative TLC on SiC 2 with methylene chloride. 

Crystalline /V-vinylphenothiazine 4 or /V-vinylcarb azole 7 reacted correspondingly at room temperature for 2 d or 18 h in the dark. Irradiations were performed with a 500-W tungsten lamp in a 250-mL round-bottomed flask under 0.9 bar CH3SH (4 1.8 mmol, 11 h, it 7 5.2 mmol, 2h, 0°C). The purity of the products was determined by ll NMR spectroscopy. 

2 Solvent-Free C-S Bond Formation under Microwave Irradiation 

Type of reaction C-S bond formation Reaction condition solvent-free 

Keywords alkyl halide, sodium phenyl sulfinate, alkylation, alumina, microwave irradiation, sulfone 

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Bromo-N-alkylnaphthalimides undergo aromatic nucleophilic substitution reaction with amines, alkoxides and thiols under microwave irradiation in the presence of KF/AI2O3 under solvent-free conditions to afford a number of fluorescent 4-sub-stituted-l,8-naphthalimide dyes. This is an efficient method for C-N, C-0 and C-S bond formation by applying suitable nucleophiles. Adducts were produced in good to excellent yields (70-95%) and relatively in short times (Bardajee, 2013). 

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