Acetic Anhydride → 5-acetoxy-12H-benzo[a]phenothiazine

HRID 979313Notes

Reaction equation

[OH:1][C:2]1[CH:15]=[C:14]2[C:5]([NH:6][C:7]3[C:12]([S:13]2)=[CH:11][CH:10]=[CH:9][CH:8]=3)=[C:4]2[CH:16]=[CH:17][CH:18]=[CH:19][C:3]=12.[C:20](OC(=O)C)(=[O:22])[CH3:21]>N1C=CC=CC=1>[C:20]([O:1][C:2]1[CH:15]=[C:14]2[C:5]([NH:6][C:7]3[C:12]([S:13]2)=[CH:11][CH:10]=[CH:9][CH:8]=3)=[C:4]2[CH:16]=[CH:17][CH:18]=[CH:19][C:3]=12)(=[O:22])[CH3:21]

Participants

Conditions

Temperature: 10 °C

Procedure

To a stirred solution of 5-hydroxy-12H-benzo[a]phenothiazine (50 g) in pyridine (115 ml) was added acetic anhydride (48 ml). The reaction was exothermic stirring was continued without cooling for 30 minutes, then the mixture was cooled to 10° C. using an ice bath. The yellow crystalline solid was filtered and washed with ether to afford the title compound (23.4 g). The product was crystallized from ethyl acetate, m.p. 185°-186° C.

Workup

temperaturewithout cooling for 30 minutes
filtrationThe yellow crystalline solid was filtered
washwashed with ether

Sources & evidence

ORD record: ord-b8a5991574da4054995da99d9baf759c
Source dataset: uspto-grants-1987_05
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US04667032

Reaction notes

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