Ethyl 2-methylacetoacetate → HCID 13105849, compound

HRID 1583338Notes

Reaction equation

HRID 1583338 reaction equation
[NH2:1][C:2]1[S:3][CH:4]=[CH:5][N:6]=1.[CH3:7][CH:8]([C:14]([CH3:16])=O)[C:9](OCC)=[O:10]>>[CH3:7][C:8]1[C:9](=[O:10])[N:6]2[CH:5]=[CH:4][S:3][C:2]2=[N:1][C:14]=1[CH3:16]

Participants

3

Reactant 2

HCID 701Ethyl 2-methylacetoacetateHCID 21552-Aminothiazole

Product 1

HCID 13105849HCID 13105849, compound

Conditions

Temperature
100 °C

Procedure

2-amino-thiazole (3.06 g) was reacted with ethyl 2-methylacetoacetate (6.4 g) in polyphosphoric acid (15.3 g: 7.1 g of P2O5 and 8.2 g of 99% H3PO4) under stirring at 100° C. for two hours. After cooling, dilution with ice water and neutralization, the precipitate was filtered, washed with water and crystallized from isopropyl ether to give 6,7-dimethyl-5H-thiazolo[3,2-a]pyrimidine-5-one, m.p. 112°-113° C. (5.04 g), which was reacted with 3-pyridine-carboxaldehyde (5.99 g) in methanol (130 ml) in the presence of sodium methoxide (4.55 g) under stirring at reflux temperature for 12 hours. After cooling the precipitate was filtered and washed with water until neutral: crystallization from methanol gave 3.2 g of 6-methyl-7-trans-[2-(3-pyridyl)-ethenyl]-5H-thiazolo[3,2-a]pyrimidine-5-one, m.p. 192°-194° C., NMR (CDCl3) δ ppm: 2.36 (s) (3H, CH3), 6.97 (d) (H, C-2 proton), 7.38 (dd) (1H, C-5 pyridyl proton), 7.38 (d) (1H, β-ethenyl proton), 7.91 (d) (1H, α-ethenyl proton), 7.97 (d) (1H, C-3 proton), 8.00 (m) (1H, C-4 pyridyl proton), 8.62 (dd) (1H, C-6 pyridyl proton), 8.88 (d) (1H, C-2 pyridyl proton); JHα Hβ =16 Hz.

Workup

  1. temperatureAfter cooling
  2. filtrationdilution with ice water and neutralization, the precipitate was filtered
  3. washwashed with water
  4. customcrystallized from isopropyl ether

Sources & evidence

ORD record
ord-783f4e395693490c9b38dd25336fc617
Source dataset
uspto-grants-1985_11
Patent number
US04551457

Reaction notes

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