تفاعل #80550

معادلة التفاعل

acetic acid

sodium cyanoborohydride

(R)-3-(N-Cyclobutylamino)-8-fluoro-5-methoxy-3,4-dihydro-2H-1-benzopyran

n-propionaldehyde

→

title compound

المردود 80.6%

(R)-3-(N-Cyclobutyl-N-n-propylamino)-8-fluoro-5-methoxy-3,4-dihydro-2H-1-benzopyran

المردود 80.6%

المذيبات

methanol

ظروف التفاعل

المعالجة

1. 1
   workup.ADDITIONadded
2. 2
   درجة الحرارةAfter 1 h the reaction was cooled (ice-bath)
3. 3
   أخرىThe solvent was removed in vacuo
4. 4
   استخلاصthe remains extracted thrice with diethyl ether
5. 5
   تجفيفThe combined ether portions were dried (MgSO4)
6. 6
   ترشيحfiltered
7. 7
   أخرىremoved in vacuo
8. 8
   أخرىto give the crude residue

الإجراء التجريبي

(R)-3-(N-Cyclobutylamino)-8-fluoro-5-methoxy-3,4-dihydro-2H-1-benzopyran (1.01 g, 4.02 mmol) was dissolved in anhydrous methanol (20 mL) and to this was n-propionaldehyde (3.0 mL, 40.2 mmol) added. After 1 h the reaction was cooled (ice-bath) then sodium cyanoborohydride (0.46 g, 7.24 mmol) was added, the pH was adjusted to 4-5 with acetic acid and the reaction was allowed to stir at room temperature over the weekend. The solvent was removed in vacuo, the remains extracted thrice with diethyl ether. The combined ether portions were dried (MgSO4) filtered, and the solvent were taken into a 2M solution of NH3 and then removed in vacuo to give the crude residue. Chromatography on silica (eluent: 11% ethyl acetate/hexane) gave 0.95 g (80% yield) of the title compound as a clear oil. [α]21D =-95.4° (C=0.1; CHCl3) GC-MS (70 eV) M=293 (1%).

المصدر