Novel base-catalyzed acylation of benzenediols with vinyl acetate: a Hirshfeld surface study

BACKGROUND

The present work describes the facile, fast and economic base-catalyzed acylation of benzenediols with vinyl acetate. The Hirshfeld surface analysis of benzene-1,4-diol O,O′-diacetate is also described. NaOH, KOH and K₂CO₃ were the bases used for the catalysis of the acylation of benzene-1,x-diols (x = 2, 3, 4) with vinyl acetate to obtain the corresponding O,O′-diacetyl derivatives.

RESULTS

The yields were quite good, up to 99% under solvent-free conditions. This method represents an alternative ‘green’ process for the preparation of O-acetyl derivatives of hydroxyaryls. The benzene-1,4-diol O,O′-diacetate crystal structure was obtained and described using Hirshfeld surface analysis. A noticeable contribution of the C⋯H contacts is shown (16.7%), despite the insignificant area of the Hirshfeld surface occupied by the carbon atoms (9.4%). By using two-dimensional fingerprint plots, it was proved that C⋯H contacts were due to the presence of π-stacking. The O⋯H contacts (41.4%) were the most numerous ones, relating mainly to typical hydrogen bonds (d_e + d_i ≈ 2.6 Å). The high saturation of the C⋯H and O⋯H contacts (enrichment ratios (E) = 1.30 and 1.36, respectively), despite their smaller contribution to the overall surface as compared to the H⋯H contacts (E = 0.84), is shown.

CONCLUSION

The novelty of this work is the development of a method based on an inexpensive, safe and easy-to-use catalyst (K₂CO₃). This method is fast with high yields. Besides, it may be used for acylation at an industrial scale. © 2024 Society of Chemical Industry (SCI).