Silica minerals recrystallization

A solution of N-(4-pyridinyl)-lH-indol-l-amine (6 g) in 25 ml of dimethylformamide was slowly added to an ice-cooled suspension of NaH (1.3 g of 60% NaH dispersion in mineral oil was washed with hexanes, the liquid was decanted and the residual solid was dispersed in 5 ml of dimethylformamide). After anion formation, a solution of 1-bromopropane (4 g) in 5 ml of dimethylformamide was added. After one hour of stirring at ambient temperature, the reaction mixture was stirred with ice-water and extracted with dichloromethane. The organic extract was washed with water and saturated sodium chloride solution, was dried over anhydrous magnesium sulfate, filtered and concentrated to 8 g of oil. This oil was purified by HPLC (silica, ethyl acetate) and thereafter by column chromatography (alumina, ether) to give 6.4 g oil. This oil was converted to the maleate salt and recrystallized from methanol/ether to give 6.8 g of crystals, m.p. 115-116°C. 

To a solution of 3-aminopropanenitrile (70 mg, 1.0 mmol) in DMF (20 mL) was added dropwise a solution of l,2,3-tris(/erf-butylsulfanyl)cyclopropenylium perchlorate (0.40g, 1.0mmol) in DMF (10mL) at rt. After stirring for 0.5 h, 50% NaH in mineral oil (0.14 g, 3.0 mmol) was added and then the mixture was heated at 80 C for 1 h. The resulting solution was poured into HjO (200 mL) containing a small amount of NaCl, extracted with EtjO/hexane, dried, and concentrated under reduced pressure. The residue was chromatographed (silica gel, hexane/EtjO 3 1) and recrystallized (hexane) to give yellow crystals yield 0.169 g (60%) mp 71 C (dec.). 

---