تفاعل #1994278

معادلة التفاعل

NaHCO3

Acetic acid

acetic anhydride

material ( 13 )

4-N-Benzoyl-5′-O-(tert-butyldimethylsilyl)-5-[3-(2,2,2-trifluoroacetamido)-prop-1-ynyl]-2′-deoxycytidine

DMSO

→

solid ( 14 )

المردود 50.0%

4-N-Benzoyl-5′-O-(tert-butyldimethylsilyl)-3′-O-methylthiomethyl-5-[3-(2,2,2-trifluoroacetamido)-prop-1-ynyl]-2′-deoxycytidine

المردود 50.0%

ظروف التفاعل

المعالجة

1. 1
   استخلاصThe aqueous layer was extracted with EtOAc (3×150 ml)
2. 2
   تجفيفdried (MgSO4)
3. 3
   ترشيحfiltered
4. 4
   أخرىevaporated
5. 5
   أخرىto yield an orange liquid that
6. 6
   أخرىwas subsequently azeotroped with toluene (4×150 ml) until material
7. 7
   أخرىCrude residue purified on silica gel (petroleum ether:EtOAc 3:1 to 2:1)

الإجراء التجريبي

The starting material (13) (2.85 g, 4.79 mmol) was dissolved in dry DMSO (40 ml) under N2 atmosphere. Acetic acid (2.7 ml, 47.9 mmol) and acetic anhydride (14.4 ml, 143.7 mmol) were added sequentially and slowly to the starting material, which was then stirred for 18 h at room temperature. Saturated NaHCO3 (150 ml) solution was carefully added to the reaction mixture. The aqueous layer was extracted with EtOAc (3×150 ml). The organic layers were combined, dried (MgSO4), filtered and evaporated to yield an orange liquid that was subsequently azeotroped with toluene (4×150 ml) until material solidified. Crude residue purified on silica gel (petroleum ether:EtOAc 3:1 to 2:1) to yield a yellow crystalline solid (14) (1.58 g, 50%). 1H NMR (d6 DMSO): δ 0.00 (s, 6H, CH3), 0.78 (s, 9H, tBu), 1.99 (s, 3H, CH3), 2.09 (m, 1H, H-2′), 2.28 (m, 1H, H-2′), 3.66 (d, 1H, J=11.5, 2.9 Hz, H-5′), 3.74 (dd, 1H, J=11.3, 2.9 Hz, H-5′), 3.99 (m, 1H, H-4′), 4.09 (m, 1H, CH2NH), 4.29 (m, 1H, H-3′), 4.61 (s, 2H, CH2S), 6.00 (m, 1H, H-1′), 7.37 (m, 2H, Ph), 7.50 (m, 2H, Ph), 7.80 (d, 1H, J=7.55 Hz, HAr), 7.97 (s, 1H, H-6), 9.79 (br t, 1H, NHCH2), 12.64 (br s, 1H, NH). Mass (−ve electrospray) calcd for C29H37F3N4O6SSi 654.79. Found 653.2.

المصدر