Yield:61296-13-7 79%

Reaction Conditions:

in water at 100;

Steps:

Representative procedure for the preparation of pyridones 6a-6g

A mixture of triacetic acid lactone (1) (0.5g, 3.96 mmol, 1equiv) and primary amine (4.35mmol, 1.1equiv) in water (2.5mL) was heated to 100°C overnight. After completion of the reaction (TLC monitoring), the reaction mixture was cooled down and the precipitate was filtered and washed with ethyl acetate and dried under vacuum to obtain the desired product.¹²1-Ethyl-4-hydroxy-6-methylpyridin-2(1H)-one (6a) (79%) Light brown solid: mp 240-242°C (lit. 247°C)⁶; Rf=0.16 (silica gel, CH₂Cl₂/EtOAc 1:1); ¹H NMR (300MHz, methanol-d₄) δ=5.92 (d, 1H), 5.72 (d, 1H), 4.05 (q, 2H), 2.39 (s, 3H), 1.24 (t, 3H) ppm; ¹³C NMR (126MHz, methanol-d₄) δ=165.74, 164.21, 145.70, 100.64 (2C), 37.09, 17.14, 11.18ppm; LRMS (ESI-QTOF) calcd for C₈H₁₂NO₂ [M+H]⁺ 154.0868, found 154.0872.

References:

Kraus, George A.;Wanninayake, Umayangani K.;Bottoms, Jashaun [Tetrahedron Letters,2016,vol. 57,# 11,p. 1293 - 1295]