반응 #2467976

반응 방정식

methyl 3-[(dimethylamino)diazenyl]-5-phenylthiophene-2-carboxylate

sodium hydroxide

HCl

→

solid

수율 64.2%

3-[(dimethylamino)diazenyl]-5-phenylthiophene-2-carboxylic acid

수율 64.2%

용매

methanol

water

반응 조건

후처리

1. 1
   workup.ADDITIONThe mixture was diluted with ice cold water
2. 2
   workup.STIRRINGThe mixture was stirred for 30 min
3. 3
   여과the precipitated solid was filtered
4. 4
   세척washed with water
5. 5
   기타dried
6. 6
   기타The solid was chromatographed over silica gel column
7. 7
   기타to give the product
8. 8
   기타The crude solid was recrystallized from hexane-chloroform

실험 절차

To a solution of methyl 3-[(dimethylamino)diazenyl]-5-phenylthiophene-2-carboxylate (1.8 g, 6.22 mmol) in methanol (50 mL) was added a solution of sodium hydroxide (1.24 g, 31.1 mmol) in water (15 mL) and stirred at rt for 16 h. The mixture was diluted with ice cold water and acidified with dil. HCl. The mixture was stirred for 30 min and the precipitated solid was filtered, washed with water and dried. The solid was chromatographed over silica gel column using hexane-ethyl acetate (70:30) as eluents to give the product. The crude solid was recrystallized from hexane-chloroform to give the product as a pale pink color solid (1.1 g, 61%), mp 162-166° C. IR (neat)νmax. 2923, 2853, 1708, 1260, 1220, 1173, 1042, 1020, 879, 836 cm−1; 1H NMR (400 MHz, CDCl3): δ 12.15 (1H, br s), 7.58-7.60 (2H, m), 7.44 (1H, s), 7.32-7.40 (3H, m), 3.65 (3H, s), 3.25 (3H, s); 13C NMR (100 MHz, CDCl3): δ 162.8, 153.3, 149.7, 133.3, 129.1, 129.0, 125.9, 120.1, 113.4, 44.3, 37.0; LC-MS (positive ion mode): m/z 298 (M+Na)+.

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