The synthetic route of Methyl 2,2-dimethoxyacetate has been constantly updated, and we look forward to future research findings.
These common heterocyclic compound, 89-91-8, name is Methyl 2,2-dimethoxyacetate, its traditional synthetic route has been very mature, but the traditional synthetic route has various shortcomings, such as complicated route, low yield, poor purity, etc, below Introduce a new synthetic route. Quality Control of Methyl 2,2-dimethoxyacetate
Cyclohexanone Compound 2a (1.37 g, 14.0 mMol) in THF (5 mL) was added dropwise to a solution of LHMDS (16.0 mL, 16.0 mMol) in anhydrous THF (25 mL) at -78 C. under a N2 atmosphere. The solution was stirred at -78 C. for about 1 hr. Methyl dimethoxyacetate Compound 11a (1.88 g, 14.0 mMol) in anhydrous THF (5 mL) was then added dropwise. The reaction mixture was stirred while warming to r.t. over a period of about 15 hrs, then the reaction was quenched with water (5 mL). The organic layer was diluted with EtOAc (100 mL) and washed with water and brine. The organic layer was separated and dried with anhydrous sodium sulfate, then filtered and concentrated in vacuo to yield a crude product as an oil. The oil was purified by flash chromatography (eluted with 10% EtOAc in hexane) to afford 2-(2,2-dimethoxy-acetyl)-cyclohexanone Compound 11b (1.82 g, 65%). Benzylhydrazine dihydrochloride Compound 11c (1.75 g, 9.00 mMol) and K2CO3 (1.51 g, 10.92 mMol) were added to a solution of Compound 11b (1.80 g, 9.10 mMol) in MeOH (50 mL) at 0 C. under a N2 atmosphere. The reaction mixture was stirred overnight while warming to r.t., then the reaction was quenched with water (20 mL). The organic layer was diluted with EtOAc (200 mL) and washed with water and brine. The organic layer was separated and dried with anhydrous sodium sulfate, then filtered and concentrated in vacuo to yield a crude product as an oil. The oil was purified by flash chromatography (eluted with 20% EtOAc in hexane) to afford 1-benzyl-3-dimethoxymethyl-4,5,6,7-tetrahydro-1H-indazole Compound 11d (1.80 g, 70%) as a colorless oil. 3N HCl (8 mL) was added to a solution of Compound 11d (1.70 g, 5.9 mMol) in acetone (50 mL) at 0 C. under a N2 atmosphere. The reaction mixture was stirred for 4 hrs while warming to r.t., then the reaction was quenched with water (20 mL), neutralized to pH 7 with K2CO3 and diluted with CH2Cl2 (100 mL). The organic layer was washed with water and brine, separated and dried with anhydrous sodium sulfate, then filtered and concentrated in vacuo to afford a 1-benzyl-4,5,6,7-tetrahydro-1H-indazole-3-carbaldehyde Compound 11e (1.35 g, 95%) as a colorless oil. Methanesulfonyl chloride Compound 11f1 (2.0 g, 17 mMol) and TEA (2.43 mL, 17.46 mMol) were added to a solution of (1R)-1-phenyl-ethylamine Compound 11f2 (1.75 g, 17.5 mMol) in CH2Cl2 (50 mL) at 0 C. under a N2 atmosphere. The mixture was stirred for 3 hrs while warming to r.t., then the reaction was quenched with water (5 mL). The organic layer was diluted with CH2Cl2 (100 mL) and then washed with water and brine. The organic layer was separated, dried with anhydrous sodium sulfate, then filtered and concentrated in vacuo to afford the corresponding N-(1-phenyl-ethyl)-methanesulfonamide Compound 11f3 as an oil. (Boc)2O (di-tert-butyldicarbonate) (4.57 g, 21.0 mMol) and DMAP (8 mg) were added to a solution of the methanesulfonamide Compound 11f3 in CH2Cl2 (10 mL) at 0 C. under a N2 atmosphere. The mixture was stirred overnight while warming to r.t., then the reaction was quenched with a saturated solution of NaHCO3 (sodium bicarbonate) (10 mL). The organic layer was diluted with CH2Cl2 (100 mL) and then washed with water and brine. The organic layer was separated, dried with anhydrous sodium sulfate, then filtered and concentrated in vacuo to yield a crude Boc-protected methanesulfonamide product. The product was purified by flash chromatography (eluted with 10% EtOAc in hexane) to afford (methylsulfonyl)[(1R)-1-phenyl-ethyl]-carbamic acid tert-butyl ester Compound 11f (3.89 g, 80%) as a colorless oil. Adapting a published procedure (Tozer M J, Woolford A J A and Linney I A, Synlett, 1998, 2, 186-188) to obtain the target compound, a 1M solution of KOtBu (potassium tert-butoxide) in THF (0.75 mL, 0.75 mMol) was added dropwise to a solution of the ester Compound 11f (0.070 g, 0.250 mMol) in anhydrous THF (5 mL) at -78 C. under a N2 atmosphere. After 45 min, Compound 11e (0.060 g, 0.250 mMol) diluted in THF (3 mL) was added dropwise. The solution was reacted over a 15 hr period while warming to ambient temperature. The reaction was quenched with water (5 mL). The organic layer was diluted with EtOAc (100 mL) and then washed with water and brine. The organic layer was separated and dried with anhydrous sodium sulfate, then filtered and concentrated in vacuo to yield a crude product. The product was purified by flash chromatography (eluted with 20% EtOAc in hexane) to give Compound 260 (0.079 g (75%), as a white solid. MS m/z 422 (MH+); 1H NMR (CDCl3, 400 MHz) delta 7.56 (d, J=15.5 Hz, 11H), 7.35-7.19 (m, 8H), 7.11-7.09 (m, 2H), 6.42 (d,J=15.5 Hz, 1H), 5.21 (s, 2H), 4.61-4.11 (m, 2H), 2.45-2.41 (m, 2H), 2.36-2.33 (m, 2H), 1.75-1.67 (m, 4H), 1.55 (d, J=6.5 Hz, 3H).
The synthetic route of Methyl 2,2-dimethoxyacetate has been constantly updated, and we look forward to future research findings.
Reference:
Patent; Lagu, Bharat; Liotta, Fina; Pan, Meng; Wachter, Michael P.; Xia, Mingde Xia; US2005/228034; (2005); A1;,
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