Acetic Anhydride → Abiraterone Acetate

HRID 525309

Reaction equation

[CH3:1][C@@:2]12[C@H:11]3[CH2:12][CH2:13][C@:14]4([CH3:25])[C:18]([C:19]5[CH:20]=[CH:21][CH:22]=[N:23][CH:24]=5)=[CH:17][CH2:16][C@H:15]4[C@@H:10]3[CH2:9][CH:8]=[C:7]1[CH2:6][C@@H:5]([OH:26])[CH2:4][CH2:3]2.[C:27](OC(=O)C)(=[O:29])[CH3:28].C(N(CC)CC)C>C(Cl)Cl>[CH3:28][C:27]([O:26][C@@H:5]1[CH2:6][C:7]2[C@@:2]([CH3:1])([C@@H:11]3[C@@H:10]([CH2:9][CH:8]=2)[C@@H:15]2[CH2:16][CH:17]=[C:18]([C:19]4[CH:20]=[CH:21][CH:22]=[N:23][CH:24]=4)[C@@:14]2([CH3:25])[CH2:13][CH2:12]3)[CH2:3][CH2:4]1)=[O:29]

Participants

Conditions

Temperature: -2.5 °C

Procedure

The crude abiraterone thus obtained (about 64 g) is taken up in methylene chloride (350 mL), and the resulting mixture, cooled to a temperature of −5 to 0° C., is added with acetic anhydride (130 mL) and then with triethylamine (190 mL), maintaining the temperature at −5 to 0° C. The mixture is stirred at room temperature for about 25 h, then washed with water and concentrated under vacuum, taking up the residue in acetone (250 mL). The resulting solid is isolated by filtration (at 0-5° C.) and dried under vacuum at 40° C. for 16 h (about 46 g; purity: 82.5%; assay: about 73%). A second fraction of crude abiraterone acetate, as an oil, is obtained by concentration of the mother liquor under vacuum (54 g, purity: 74%, assay: about 45%).

Workup

washwashed with water
concentrationconcentrated under vacuum
customThe resulting solid is isolated by filtration (at 0-5° C.)
customdried under vacuum at 40° C. for 16 h (about 46 g; purity: 82.5%; assay: about 73%)

Sources & evidence

ORD record: ord-0907400267d446e097fd7a128ebf2ddc
Source dataset: uspto-grants-2016_05
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US09340571B2

Linked notes

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