반응 #4981

반응 방정식

2,4-dihydroxy-3-methylbenzaldehyde

Phosphoric acid

→

solid

수율 72.0%

2,4-dimethylresorcinol

수율 72.0%

용매

isopropanol

반응 조건

후처리

1. 1
   온도cooled in a 5 L 3-neck flask
2. 2
   기타fitted with a magnetic stirrer
3. 3
   기타the solution was sparged with nitrogen
4. 4
   기타(c. 1.5 hour)
5. 5
   기타was again sparged with nitrogen
6. 6
   여과filtered through Celite®
7. 7
   세척the resulting solution washed with water (4×100 mL)
8. 8
   추출The water washes were back-extracted with ethyl acetate
9. 9
   건조the combined organic layers dried over sodium sulfate

실험 절차

A solution of 2,4-dihydroxy-3-methylbenzaldehyde (30.0 g, 197 mmol) with isopropanol (3 L) was ice-cooled in a 5 L 3-neck flask fitted with a magnetic stirrer. Phosphoric acid (4 mL) and d10% palladium on carbon were added and the solution was sparged with nitrogen, then hydrogen. When uptake was judged to be complete (c. 1.5 hour) the solution was again sparged with nitrogen and then filtered through Celite®. The solvent was stripped off, the residue taken up in ethyl acetate, and the resulting solution washed with water (4×100 mL). The water washes were back-extracted with ethyl acetate and the combined organic layers dried over sodium sulfate and stripped down. Sublimation (95°, 0.05 torr) afforded a colorless solid (19.6 g, 72%). M.p. 107°-8° C. (Lit. 108°-109° C. [W. Baker et al., J. Chem. Soc., 2834-5 (1949).]). NMR (DMSO-d6): δ 1.969 (s, 3H), 2.037 (s, 3H), 6.220 (d, J=8.1 hz, 1H), 6.637 (d, J=8.1 hz, 1H), 7.929 (s, 1H), and 8.785 (s, 1H).

출처