3,4,5,6-Tetrahydrophthalic anhydride → HCID 51353550, compound

Participants

Reaction Steps

6-amino-2,2,7-trifluoro-4-(prop-2-ynyl)-2H-benzo[b][1,4]oxazin-3(4H)-one (20 g, 78 mmol) and 4,5,6,7-tetrahydroisobenzofuran-1,3-dione (12.47 g, 82 mmol) in acetic acid (500 ml) were stirred at 120° C. overnight, after which time tlc (thin layer chromatography) analysis indicated that the reaction was complete. The reaction mixture was concentrated in vacuo and triturated with toluene to yield 34.6 g of crude product. This material was combined with a further quantity (6.23 g) of crude product which had been obtained in a similar manner, and the combined product was coated on isolute absorbens (˜70 g). Filtration over silica afforded 2 fractions: F1: 12.9 g and F2: 19.35 g. Both fractions were triturated with di-isopropyl ether to yield: T1: 6.04 g (88% purity) and T2: 14.7 g (>95% purity). T1 was recrystallised from MeOH to yield a further 4.65 g of product (>95% purity).

Provenance & Evidence