Acetylsalicylic anhydride

Synthesis of 2-acetoxybenzoic anhydride (Aspirin anhydride): A suspension of 2- acetoxybenzoic acid (5.0 g, 28 mmol) in 30 mL of CHGeneral procedure: To a solution of iodine (0.1573 g, 0.62 mmol) in CH2Cl2 (2 mL) was added with triphenylphosphine (0.1626 g, 0.62 mmol) in one portion at 0 oC. Carboxylic acid (0.41 mmol)was subsequently added into the mixture, followed by addition of triethylamine (0.17 mL, 1.23mmol) at 0 oC. The reaction mixture was allowed to warm up to room temperature and stirred until completion of the reaction (typically within 10 min). The crude mixture was concentrated under reduced pressure and then purified by column chromatography (CC) using 5-10percent ethylacetate in hexane to give the desired anhydride product.[0098] Synthesis of 2-acetoxybenzoic anhydride (Aspirin anhydride): A suspension of 2- acetoxybenzoic acid (5.0 g, 28 mmol) in 30 mL of CH2Cl2 was prepared and a solution of DCC (2.9 g, 13.9 mmol) in 10 mL of CH2Cl2 was added. The reaction mixture was stirred at room temperature for overnight. The byproduct, dicyclohexylurea (DCU), was filtered off in a glass filter and washed with a small amount of CH2C12. The solvent was evaporated and the resulting residue was taken up in ethyl acetate. Residual DCU was removed by filtering the resulting suspension through a glass filter. The filtrate was evaporated to give anhydride as transparent thick oil, which solidified upon storing at -20C. Yield 4.6 g, quantitative. 1H NMR (CDC13, 400 MHz): delta ppm, 8.08 (d, 2H, J= 7.9 Hz), 7.70 (t, 2H, J= 7.8 Hz), 7.40 (t, 2H, J = 7.7 Hz), 7.19 (d, 2H, J = 8.1 Hz), 2.31 (s, 6H). 13C NMR (CDC13, 100 MHz): delta 169.42, 159.29, 151.83, 135.54, 132.24, 126.29, 124.42, 121.69, 20.89. IR (KBr) umax (cm-1): 3570 (w), 3491 (w), 3445 (w), 3332 (br), 3205 (w), 3100 (s, C-H), 2932 (s, C-H), 2855 (w), 2409 (w), 2032 (w), 1789 (br, C=0), 1728 (br, C=0), 1603 (s, C=C), 1581 (s), 1484 (s, 5asCH3), 1451 (s), 1369 (s, 5sCH3), 916 (s). 506 (s). HRMS m/z Calcd. for Ci8Hi4Na07: (M + Na)+ 365.0637. Found 365.0638. Melting point: 80-85C.General procedure: To a solution of iodine (0.1573 g, 0.62 mmol) in CH2Cl2 (2 mL) was added with triphenylphosphine (0.1626 g, 0.62 mmol) in one portion at 0 oC. Carboxylic acid (0.41 mmol)was subsequently added into the mixture, followed by addition of triethylamine (0.17 mL, 1.23mmol) at 0 oC. The reaction mixture was allowed to warm up to room temperature and stirred until completion of the reaction (typically within 10 min). The crude mixture was concentrated under reduced pressure and then purified by column chromatography (CC) using 5-10% ethylacetate in hexane to give the desired anhydride product.

Acetylsalicylic Acid (A187780) Impurity D.

Molecular Weight:342.3
XLogP3:2.5
Hydrogen Bond Acceptor Count:7
Rotatable Bond Count:8
Exact Mass:342.07395278
Monoisotopic Mass:342.07395278
Topological Polar Surface Area:96
Heavy Atom Count:25
Complexity:482
Covalently-Bonded Unit Count:1
Compound Is Canonicalized:Yes