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ChemicalBook CAS DataBase List 2-Hydroxypyridine
142-08-5

2-Hydroxypyridine synthesis

9synthesis methods
-

Yield:142-08-5 95.9%

Reaction Conditions:

with hydrogenchloride in methanol;

Steps:

1.a EXAMPLE 1

a) 100 ml of methanol and 29 g of n-hexylamine (0.287 mol) were charged initially and admixed at 30-35° C. with 32.8 g (0.287 mol) of ethyl cyanoacetate over 2 h. The mixture was subsequently stirred at 30° C. for 2 h. 25 g of piperidine were added, followed by 52.8 g (0.287 mol) of ethyl 4,4,4-trifluoroacetoacetate. The reaction mixture was then refluxed for 14 h and the solvent was removed at a temperature rising to 100° C. The rest was added while still hot to 450 g of ice and 75 ml of concentrated hydrochloric acid. The product was filtered off with suction, washed neutral with cold water and dried at 50° C. under reduced pressure, leaving 79.3 g of pyridone of formula STR5 yield: 95.9% b) 4.0 g (0.02 mol) of aldehyde of the formula STR6 and 5.8 g (0.02 mol) of the compound described in Example 1a) were heated to 130° C. in 20 ml of acetic anhydride for 30 min. Cooling brought down a precipitate of a brilliant red dye of the formula STR7 which was filtered off with suction, washed with a little methanol and dried at 50° C. under reduced pressure. Yield: 6.6 g (70%) λmax: 538 nm (CH2 Cl2)

References:

US6086637,2000,A

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