Hydrazine hydrate (1:1) → HCID 178422445, compound

HRID 1602775Notes

Reaction equation

HRID 1602775 reaction equation
[Br:1][C:2]1[CH:3]=[C:4]([CH3:14])[C:5]2[S:10][CH2:9][CH2:8][C:7](=O)[C:6]=2[C:12]=1[CH3:13].COC(OC)[N:18]([CH3:20])C.O.[NH2:24]N>C(OCC)(=O)C>[Br:1][C:2]1[CH:3]=[C:4]([CH3:14])[C:5]2[S:10][CH2:9][C:8]3[C:7](=[N:24][NH:18][CH:20]=3)[C:6]=2[C:12]=1[CH3:13]

Participants

5

Reactant 3

HCID 24654Hydrazine hydrate (1:1)HCID 78373Dimethylformamide dimethyl acetalHCID 152784955,8-Dimethyl-6-bromothiochroman-4-one

Product 1

HCID 178422445HCID 178422445, compoundYield 105%

Reagents, catalysts & solvents 1

HCID 8857Ethyl AcetateSolvent2×

Procedure

2.80 g (10 mmol) of the title compound of Step B and 1.79 g(15 mmol) of N,N-dimethylformamide dimethyl acetal were dissolved in 16 mL of ethyl acetate and heated to reflux. The methanol/ethyl acetate mixture was removed via a Dean Stark trap and was replaced with fresh ethyl acetate. After heating to reflux for 4 hours, the reaction was cooled to room temperature and allowed to stand overnight. It was then reluxed further for 2 hours, cooled to 60° C., and 0.75 g (15 mmol) of hydrazine monohydrate was added. The reaction was reheated to reflux for 1 hour, cooled to room temperature, and diluted to 100 mL with ethyl acetate. The organic phase was washed twice with 100 mL of water, dried over magnesium sulfate, and concentrated under reduced pressure to yield 3.10 g of an oily yellow solid. This solide was triturated with hexanes, collected by filtration, washed further with hexanes, and dried to yield 2.79 g of the title compound of Step C as a pale yellow solid melting at 162-164° C. 1H NMR (CDCl3): δ2.34 (s, 3H), 2.79 (s, 3H), 3.84 (s, 2H), 7.35 (s, 1H), 7.46 (s, 1H), 10.4 (br s).

Workup

  1. temperatureheated to reflux
  2. customThe methanol/ethyl acetate mixture was removed via a Dean Stark trap
  3. temperatureAfter heating
  4. temperatureto reflux for 4 hours
  5. waitIt was then reluxed further for 2 hours
  6. temperaturecooled to 60° C.
  7. temperatureto reflux for 1 hour
  8. temperaturecooled to room temperature
  9. washThe organic phase was washed twice with 100 mL of water
  10. dry with materialdried over magnesium sulfate
  11. concentrationconcentrated under reduced pressure

Sources & evidence

ORD record
ord-8d14b1f029da40efa62e23c61f0093b8
Source dataset
uspto-grants-1999_11
Patent number
US05985799

Reaction notes

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