ChemicalBook CAS DataBase List 2-METHOXYTETRAHYDROPYRAN

2-METHOXYTETRAHYDROPYRAN synthesis

13synthesis methods

Product Name:2-METHOXYTETRAHYDROPYRAN
CAS Number:6581-66-4
Molecular formula:C6H12O2
Molecular Weight:116.16

To a flask equipped with a stirrer and containing 84.0 gm (1.0 mole) of 2,3-dihydropyran in the presence of 1 ml of cone, hydrochloric acid is added 32.0 gm (1.0 mole) of methanol. The reaction is exothermic and is stirred for 3 hr. Then a few pellets of sodium hydroxide are added to make the reaction basic. The mixture is directly distilled to afford 98.6 gm (85%), b.p. 125°C (760 mm Hg).

Preparation of 2-Methoxytetrahydropyran

4454-05-1 Synthesis

4454-05-1
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$9.00/25g

6581-66-4
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$21.00/1g

Yield: 96%

Reaction Conditions:

with hydrogen;palladium on activated carbon at 20; under 6000.6 - 15001.5 Torr; for 1.5 h;Product distribution / selectivity;

Steps:

2; 3; 8
Example 2:; In a 100 mL-volume autoclave made of stainless steel, 23.17 g of 3,4-dihydro-2-methoxy-2H-pyran(DHMP) and 0.42 g of 5 mass % palladium/activated carbon powder(Pd/C) were placed. The reactor was purged with hydrogen, and 0.8 MPa of hydrogen was introduced. This was stirred at a room temperature and hydrogen was continuously introduced into the reactor so that the pressure 0.8 MPa was maintained during the reaction. In this step, the amount of the hydrogen gas introduced into the reactor was 4737 ml(Step-l) . After 1.5 hour, DHMP as raw material was not detected. Tetrahydro-2-methoxy-2H-pyran(THMP) was produced at a yield of 96 %. After adding 1.10 g of sodium hydrogen sulfate hydrate to the reaction mixture, the pH of the reaction mixture measured was 1 (Step-2) . As in Step-1, the reactor was pressurized to 0.8 MPa with hydrogen. Reaction was performed at 70°C for 2 hours, 100⁰C for 2 hours, and then 130 ⁰C for 1.5 hours, while continuously introducing hydrogen into the reactor. In this step, the amount of the hydrogen gas introduced into the reactor was 3989 ml(Step-3) .As a result of the reaction mixture after the reaction, the yield of tetrahydropyran(THP) was 82 %. THMP was generated at a yield of 1 % and methanol was generated at a yield of 80 % based on the amount of the raw material.; Example 3:; The same procedures were carried out as in Example 2 except that 23.79 g of 3, 4-dihydro-2-methoxy-2H-pyran(DHMP) and 0.21 g of 5 mass % palladium/activated carbon powder(Pd/C) were used and that 0.38 g of p-toluene sulfonic acid monohydrate was EPO used instead of sodium hydrogen sulfate hydrate. As a result, the amount of the hydrogen gas introduced into the reactor in Step-1 was 4872 ml. The yield of tetrahydro-2-methoxy-2H-pyran(THMP) in Step-1 was 97 %. The pH of the reaction mixture in Step-2 was 1. Further, the amount of the hydrogen gas introduced into the reactor in Step-3 was 3418 ml. The yield of the obtained tetrahydropyran(THP) was 70 %, the yield of the by-produced THMP was 20%, and the yield of the generated methanol was 67 %.; Example 8:; Reduction reaction was performed by carrying out the same procedures as in Example 2 except that 23.22 g of 3, 4-dihydro-2- methoxy-2H-pyran(DHMP) was used and that reaction pressure was 2.0 MPa. As a result of analysis on the reaction mixture after23 EPO the reaction, the yield of tetrahydropyran(THP) was 94 %. Tetrahydro-2-methoxy-2H-pyran(THMP) was not detected and methanol was generated at a yield of 92 % based on the amount of the raw material.

References:

SHOWA DENKO K.K. WO2006/62211, 2006, A1 Location in patent:Page/Page column 21-24

110-87-2 Synthesis