Acetohydrazide → 8-methoxy-1,4-dimethyl-5,6-dihydro-4H-pyrido[2,3-b][1,2,4]triazolo[4,3-d][1,4]diazepine

Temperature

130 °C

To a solution of 7-methoxy-3-methyl-4,5-dihydro-1H-pyrido[2,3-b][1,4]diazepine-2(3H)-thione (1.8 g, 8.06 mmol) in n-butanol (25 mL) was added acetohydrazide (5.97 g, 80.61 mmol). The mixture was stirred at 130° C. for 3 hours. The reaction mixture was concentrated in vacuo and washed with brine (20 mL), and then the mixture was filtered through a celite pad. The filtrate was extracted with acetic ester (20 mL×3). The combined organic phase was dried by anhydrous sodium sulphate, and then filtered. The filtrate was concentrated and purified by column chromatograph silica gel (elute: dichloro methane/Methanol: 80:1→35:1→20:1) to give 8-methoxy-1,4-dimethyl-5,6-dihydro-4H-pyrido[2,3-b][1,2,4]triazolo[4,3-d][1,4]diazepine (1.2 g, 61%) as a yellow solid.

1. concentrationThe reaction mixture was concentrated in vacuo
2. washwashed with brine (20 mL)
3. filtrationthe mixture was filtered through a celite pad
4. extractionThe filtrate was extracted with acetic ester (20 mL×3)
5. dry with materialThe combined organic phase was dried by anhydrous sodium sulphate
6. filtrationfiltered
7. concentrationThe filtrate was concentrated
8. custompurified by column chromatograph silica gel (elute: dichloro methane/Methanol: 80:1→35:1→20:1)

ORD record

ord-2911005f861f44a0993a2dca05b9e45b

Source dataset

uspto-grants-2016_08

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US09422292B2