تفاعل #1851974

معادلة التفاعل

hydrogen chloride

Oxalyl chloride

3-[(4-fluorophenyl)sulfonyl]propanoic acid

AlCl3

→

6-fluoro-2,3-dihydro-4H-1-benzothiopyran-4-one

المردود 93.3%

المذيبات

water

dichloromethane

ظروف التفاعل

المعالجة

1. 1
   تركيزwas concentrated under reduced pressure to a residue
2. 2
   درجة الحرارةcooled to 0° C. in an ice bath
3. 3
   workup.ADDITIONCS2 (1 mL) was added
4. 4
   درجة الحرارةto warm to room temperature
5. 5
   workup.STIRRINGstirred over night
6. 6
   workup.STIRRINGstirred
7. 7
   استخلاصextracted with dichloromethane (3×150 mL)
8. 8
   غسيلwashed with brine (1×100 mL) and water (1×100 mL)
9. 9
   تجفيفdried (sodium sulfate)
10. 10
    تركيزconcentrated to a yellow solid
11. 11
    أخرىThe solid was purified by flash column chromatography on 100 g silica gel
12. 12
    غسيلeluting 10% ethyl acetate in hexanes

الإجراء التجريبي

3-[(4-fluorophenyl)sulfonyl]propanoic acid (3 g, 15 mmol) was dissolved in dichloromethane (30 mL ) and cooled to 0° C. in an ice bath. Oxalyl chloride (10 mL) was added slowly, dimethyl formamide (1 drop) was added and the reaction mixture was stirred at 0° C. for 0.5 hours. At which point the reaction was concentrated under reduced pressure to a residue, then resuspended in dichloromethane and cooled to 0° C. in an ice bath, CS2 (1 mL) was added and AlCl3 (4 g, 15 mmol) was added slowly. The reaction mixture was then allowed to warm to room temperature and stirred over night. Ice chips and water (250 mL) were added and stirred. Concentrated hydrogen chloride was added until pH of 2, and extracted with dichloromethane (3×150 mL). Organics were combined, washed with brine (1×100 mL) and water (1×100 mL), dried (sodium sulfate), and concentrated to a yellow solid. The solid was purified by flash column chromatography on 100 g silica gel, eluting 10% ethyl acetate in hexanes to give 6-fluoro-2,3-dihydro-4H-1-benzothiopyran-4-one (2.55 g, 93%). 1H NMR (CDCl3, 300 MHz): δ 7.80-7.76 (m, 1H), 7.27-7.23 (m, 2H), 7.15-7.09 (m, 1H), 3.23 (t, 2H, J=6.4 Hz), 2.97 (t, 2H, J=6.4 Hz) ppm.

المصدر