ChemicalBook CAS DataBase List (S)-(+)-2-Pentanol

(S)-(+)-2-Pentanol synthesis

8synthesis methods

Product Name:(S)-(+)-2-Pentanol
CAS Number:26184-62-3
Molecular formula:C5H12O
Molecular Weight:88.15

6032-29-7 Synthesis

6032-29-7
176 suppliers
$14.00/5mL

26184-62-3
154 suppliers
$50.00/250mg

Yield:26184-62-3 81%

Reaction Conditions:

Stage #1:(+/-)-2-pentanol with phthalic anhydride;triethylamine at 20 - 70; for 3 h;
Stage #2: with hydrogenchloride in dichloromethane at 0;Further stages;

Steps:

1 Method for synthesizing high purity (S)- (+) -2 - pentanol process method, specific implementation steps are as follows:
(1) Preparation of 10 L reactor, under the room temperature condition, are first added 2 - pentanol (2.5 L, 23.3 μM), phthalic anhydride (3.45 kg, 23.3 μM), stirring;(2) In the 45 - 50 °C conditions, slowly dropping triethylamine (1.18 kg, 11.6 μM), with exothermic phenomenon, after dropping, the reaction in the 65 - 70 °C ripening under the conditions of 3 hours;(3) After the reaction, the reaction liquid is transferred to the 45 L in the reactor, and then slowly adding 12 L of 1 N dilute hydrochloric acid, stirring, by adding dichloromethane extraction (5 L × 2), combined with the organic phase, magnesium sulfate drying, filtering, the filtrate is adding to the 10 L hexane, cooled to 0 °C, standing overnight, a large number of solid precipitation, filtration, vacuum drying to obtain 4.6 kg white crystal DL - Ester;(4) Will be 1.55 kg white crystal DL - Ester added to the 5.5 L in acetone, stirring, at room temperature, then dropwise (S)- (-) -1 - phenethylamine (800 g, 6.6 μM), a large number of white crystalline appear, and milling and then heating to reflux 1 hour;(5) After the reaction, cooling to room temperature, filtered, the filter cake is for 1.28 L acetone hangs washes, decompression drying to obtain the 894 G crystallization; and then adding this crystal in 4.5 L of acetone, heating reflux for 1 hour, cooling to room temperature, filtered, the filter cake for 1 L acetone hangs washes, reduced-pressure drying, to obtain 737 G white crystalline D - Ester - L - Amine;(6) Will be 2.2 kg of white crystalline D - Ester - L - Amine added to the 12 L 1 N HCl solution, stirring 1 hour, then dichloromethane is used for extraction (5 L × 2), combined with the organic phase, dried magnesium sulfate, filtered, concentrated under reduced pressure to obtain 1.44 kg of white crystalline (+) - Ester;(7) The NaOH (700 g, 17.5 μM) is added to the 2 L H₂In O, stirring to dissolve, then adding 1.44 kg of white crystalline (+) - Ester, heating 80 - 95 °C, reaction 3 hours; after the reaction, cooling to room temperature, layered, water layer and then dichloromethane is used for extraction (2 L × 2), combined with the organic phase, dried, concentrated under reduced pressure, to obtain 500 G crude (S)- (+) -2 - pentanol;(8) The 500 G obtained by atmospheric distillation, collecting 117 - 118 °C fraction, to obtain 435 G pure product (S)- (+) -2 - pentanol, yield is 81%, after the detection, the product GC purity of 99.5%, specific gravity (20/20) is 0.8104, [...] n20/D is 1.4063, optical rotation is + 13.8 deg, ee value is 99.5%.

References:

Shanghai Aladdin Biochemical Technology Co., Ltd.;Kan Hongzhu CN108440240, 2018, A Location in patent:Paragraph 0006-0007; 0030-0038

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139406-51-2 Synthesis