Réaction #5234

Équation de réaction

lithium borohydride

1-(cyclopropylcarbonyl)-4-carboethoxy piperidine

Trimethyl borate

→

liquid

Rendement 63.7%

1-(Cyclopropylcarbonyl)-4-hydroxymethylpiperidine

Rendement 63.7%

Solvants

Water

tetrahydrofuran

tetrahydrofuran

water

Conditions de réaction

Traitement

1. 1
   workup.STIRRINGwith vigorous stirring until the vigorous gas evolution
2. 2
   Extractionextracted three times with ethyl acetate
3. 3
   SéchageThe combined organic layers were dried over magnesium sulfate
4. 4
   Filtrationfiltered
5. 5
   Concentrationconcentrated in vacuo
6. 6
   workup.DISTILLATIONVacuum distillation (bp 165° C., 0.5 mm Hg)

Mode opératoire

A solution of 1-(cyclopropylcarbonyl)-4-carboethoxy piperidine (35 g, 156 mmol) in anhydrous tetrahydrofuran (350 mL) was stirred at ambient temperature under a nitrogen atmosphere. A solution of lithium borohydride in tetrahydrofuran (2M, 78 mL, 156 mmol) was added dropwise. Trimethyl borate (1.77 mL, 15.7 mmol) was added, then the reduction mixture was stirred for about 48 hours. Water was added dropwise with vigorous stirring until the vigorous gas evolution ceased. The mixture was diluted twofold with water and extracted three times with ethyl acetate. The combined organic layers were dried over magnesium sulfate, filtered and concentrated in vacuo. Vacuum distillation (bp 165° C., 0.5 mm Hg) gave a clear, colorless liquid (18.2 g): IR (neat): 3410 (br, s), 3094 (w), 3008 (s), 2918 (s), 2858 (s), 1738 (m), 1613 (s), 1448 (s), 1375 (s), 1316 (s); 1H-NMR: 4.7-4.5 (m, 1H), 4.4-4.1 (m, 1H), 3.6-3.4 (m, 2H), 3.2-2.5 (m, 3H), 2.0-1.7 (m, 4H), 1.4-1.1 (m, 1H), 1.0-0.8 (m, 2H), 0.8-0.65 (m, 2H); HRMS: Calcd for C10H17NO2 :183.1259; Found: 183.1250; Anal.: Calcd for C10H17NO2 :C, 65.54, H, 9.35, N, 7.64; Found: C, 65.83, H, 9.43, N, 7.50.

Source