تفاعل #603576

معادلة التفاعل

water

benzyl 1-piperazinecarboxylate

DIPEA

2-chloroethanesulfonyl chloride

→

benzyl 4-(vinylsulfonyl)-1-piperazinecarboxylate

المردود 43.0%

المذيبات

CH2Cl2

ظروف التفاعل

المعالجة

1. 1
   درجة الحرارةto warm to 0° C. over 30 min
2. 2
   أخرىThe organic layer was separated
3. 3
   غسيلwashed successively with dil. HCl and aq. NaHCO3
4. 4
   أخرىAfter drying
5. 5
   أخرىthe solvent was removed
6. 6
   أخرىthe residue was chromatographed on silica
7. 7
   غسيلeluting with CH2Cl2/EtOAc 95:5
8. 8
   أخرىto give an oil, which
9. 9
   أخرىwas recrystallized from CH2Cl2/hexanes

الإجراء التجريبي

A mixture of 11 g (50 mmol) of benzyl 1-piperazinecarboxylate and 16.1 g (125 mmol) of DIPEA in 200 mL CH2Cl2 was cooled to −15° C. and 6.3 mL (9.8 g, 60 mmol) of 2-chloroethanesulfonyl chloride was added slowly over 15 min. The mixture was allowed to warm to 0° C. over 30 min and water was then added. The organic layer was separated and washed successively with dil. HCl and aq. NaHCO3. After drying, the solvent was removed and the residue was chromatographed on silica, eluting with CH2Cl2/EtOAc 95:5, to give an oil, which was recrystallized from CH2Cl2/hexanes to give 6.64 g (43% yield) of benzyl 4-(vinylsulfonyl)-1-piperazinecarboxylate: mp (CH2Cl2/hexanes) 85-87° C.; 1H NMR (CDCl3) δ 7.39-7.30 (m, 5H), 6.40 (dd, J=16.6, 9.8 Hz, 1H), 6.25 (d, J=16.6 Hz, 1H), 6.06 (d, J=9.8 Hz, 1H), 5.14 (s, 2H), 3.61 (m, 4H), 3.14 (m, 4H); Anal. Calcd. for C14H18N2O4S: C, 54.2; H, 5.85; N, 9.0. Found: C, 54.1; H, 5.7; N, 9.1%.

المصدر