35% |
With nitric acid In sulfuric acid |
1.10 Synthesis of 5-Nitro-1,3,3-Trimethyl-2-Methyleneindoline
Example 1.10 Synthesis of 5-Nitro-1,3,3-Trimethyl-2-Methyleneindoline This compound was prepared by the general synthesis method 1d) from a solution of 20 g of 1,3,3-trimethyl-2-methyleneindoline in 50 mL of 97% sulfuric acid and 23.5 mL of nitrating acid (a mixture of 3.5 mL of fuming 99% nitric acid and 20 mL of 97% sulfuric acid). The crude product was crystallized from hexane/methylene chloride. Yield: 8.8 g of 5-nitro-1,3,3-trimethyl-2-methyleneindoline (35% of the theoretical). Melting point: 89-91° C. 1H-NMR (CDCl3): δ=1.35 ppm (s, 6H); 3.11 ppm (s,3H); 4.09 ppm (d, 2J=3 Hz, 1H); 4.11 ppm (d, 2J=2.5 Hz, 1H); 6.51 ppm (d, 3J=9 Hz, 1H); 7.91 ppm (d, 4J=2.5 Hz, 1H); 8.11 ppm (dd, 2J=9 Hz, 4J=2.5 Hz, 1H); El mass spectrum: 218 (85, M+); 203 (100); 188 (6); 171 (16); 157 (91); 145 (32); 1.45 (32); 1.28 (24); 115 (44); 103 (10); 89 (15); 77 (14); 63 (12). |
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With sulfuric acid; nitric acid for 3h; |
S1 S1: Synthesis of 5-nitro-3,3-dimethyl-1'-methyl-2-methyleneindole Specific structural formulas are as follows,
8.00 g of 3,Dimethyl-1'-methyl-2-methyleneindole was slowly added dropwise to a 250 ml three-necked round bottom flask containing 20 ml of concentrated sulfuric acid,Dropping process continuously stirring,After the completion of this operation to the flask dropping fuming nitric acid and concentrated sulfuric acid mixed solution, after the completion of the reaction to continue after 3h,Seal overnight.The reaction solution was poured into a 1000 ml large beaker containing ice cubes,To the beaker slowly dropping saturated NaOH solution while stirring constantly,Until a large number of red fluffy solid appears, and then vacuum filtration,Washed thoroughly with a large amount of distilled water, dried,Recrystallization gave bright yellow crystals, mp 84.2-85.1 ° C. |