ChemicalBook CAS DataBase List 5,6-DIHYDRO-2H-PYRAN-2-ONE

5,6-DIHYDRO-2H-PYRAN-2-ONE synthesis

8synthesis methods

Product Name:5,6-DIHYDRO-2H-PYRAN-2-ONE
CAS Number:3393-45-1
Molecular formula:C5H6O2
Molecular Weight:98.1

50-00-0 Synthesis

50-00-0
846 suppliers
$10.00/25g

625-38-7 Synthesis

625-38-7
160 suppliers
$25.00/5g

3393-45-1
121 suppliers
$22.00/250mg

Yield:3393-45-1 85%

Reaction Conditions:

with sulfuric acid;acetic acid at 90 - 115; for 6 h;

Steps:

1-2
(1) Prepare a 10L glass reactor, and first add 3L of acetic acid, vinylacetic acid (1kg, 7.55mol), and paraformaldehyde (0.36kg, 11.32mol) in this order.Stir and slowly add concentrated sulfuric acid (4.1ml, 0.075mol),After the dropwise addition, it is heated to 90-100 ° C. After the reaction is exothermic, the temperature is gradually increasedThe internal temperature is controlled to mature for 6h at 100~115°C ;(2) After the reaction is completed, add sodium acetate (0.31kg, 3.77mol), stir for half an hour, and concentrate. Remove the solvent acetic acid.The internal temperature is controlled below 10 ° C, and 2.1L of 10% sodium hydroxide solution is added dropwise.Adjust the pH of the concentrated solution to 7-8, then extract with dichloromethane (4L × 3), separate the layers,The organic phase was washed with a saturated sodium chloride solution (4L × 1), dried over magnesium sulfate (300g),After suction filtration and concentration, 712 g of crude compound I was obtained;(3) Distilling 712g of crude compound I under reduced pressure, selecting a 50cm glass packed column for rectification, heating with a water bath, collecting 85-92 ° C / 5-7mmHg fractions to obtain 629.5g of compound I, with a GC purity of 98.6% the yield is 85%;

References:

Shanghai Aladdin Biochemical Technology Co., Ltd.;Kan Hongzhu;Xu Jiuzhen CN110437193, 2019, A Location in patent:Paragraph 0027-0031; 0042-0046

FullText