ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Phthalides and 1,3-indandiones. XXI. Perkin synthesis of 7-nitro-3-benzalphthalide and 4-nitro-3-benzalphthalide; their reduction and conversion into 4-acetamino-2-phenylindan-1,3-dione

P. Hrnčiar and D. Joniak

Komenský University, Bratislava

Abstract:   Gabriel's modification of the Perkin synthesis, by the condensation of the anhydride of 3-nitrophthalic acid with the phenylacetic acid (in 2 hrs. at 150-230°) gave 7-nitro-3-benzalphthalide (1), m. 153-4°, and 4-nitro-3-benzalphthalide (II), m. 206-8°. Higher temps. (225-230°) yielded mostly I (26.8% I and 1.7% II) and lower temps. (150-155°) mostly II (15.3% II and 6.3% I). These isomers were sepd. by chromatography on silica gel or by the fractional crystn. from AcOH. Zelmen and Vanag (V. and Z., CA 55, 17593b) isolated only I. The structure of these isomers was detd. by formation of a lactone ring and by redn. with 56% HI. Redn. of the nitro group of the phthalides by SnCl₂.2H₂O in concd. HCl, gave 7-amino-3-benzalphthalide, or 4-amino-3-benzalphthalide, resp., which by the rearrangement by MeONa in MeOH, form only one 4-amino- 2-phenylindan-1,3-dione, m. 207-9°, which is also formed by the redn. of the 4-nitro-2-phenylindan-1,3-dione. Rearrangement of the 7-acetamido-3-benzalphthalide gave, resp., 4-acetamido-3-benzalphthalide, or 4-acetamido-2-phenylindan-1,3-dione, m. 123-5°.

Full paper in Portable Document Format: 205a336.pdf (in Slovak)

Chemical Papers 20 (5) 336–344 (1966)