Reaction #631985

Reaction equation

5-Ethyl-2,3-dihydro-benzo[1,4]dioxine-6-carboxylic acid N′-(1-tert-butyl-3,4,4-trimethyl-pent-2-enyl)-hydrazide

3,5-dimethoxy-4-methylbenzoyl chloride

K2CO3

→

3,5-dimethoxy-4-methyl-benzoic acid N-(1-tert-butyl-3,4,4-trimethyl-pent-2-enyl)-N′-(5-ethyl-2,3-dihydro-benzo[1,4]dioxine-6-carbonyl)-hydrazide

Yield 38.0%

Solvents

CH2Cl2

Conditions

Workup

1. 1
   OtherThe phases were separated
2. 2
   workup.ADDITIONadding additional CH2Cl2 and/or water
3. 3
   DryingThe CH2Cl2 layer was dried
4. 4
   Othersolvent was removed in vacuo
5. 5
   Otherto provide 210 mg of crude product
6. 6
   OtherThis material was purified by silica gel column chromatography
7. 7
   Washeluting with a step gradient of 10-25% ethyl acetate in hexane

Procedure

5-Ethyl-2,3-dihydro-benzo[1,4]dioxine-6-carboxylic acid N′-(1-tert-butyl-3,4,4-trimethyl-pent-2-enyl)-hydrazide (150 mg, 0.39 mmol) and 3,5-dimethoxy-4-methylbenzoyl chloride (83 mg, 0.39 mmol) were dissolved in 5 mL CH2Cl2. 5 mL of 25% K2CO3 were added, and the reaction mixture was stirred at room temperature overnight. The reaction was monitored by TLC. The phases were separated, adding additional CH2Cl2 and/or water as needed to aid manipulation. The CH2Cl2 layer was dried and solvent was removed in vacuo to provide 210 mg of crude product. This material was purified by silica gel column chromatography, eluting with a step gradient of 10-25% ethyl acetate in hexane to yield 3,5-dimethoxy-4-methyl-benzoic acid N-(1-tert-butyl-3,4,4-trimethyl-pent-2-enyl)-N′-(5-ethyl-2,3-dihydro-benzo[1,4]dioxine-6-carbonyl)-hydrazide RG115898 (83 mg, Rf=0.19 in 25% ethyl acetate in n-hexane, yield 38%). 1H NMR (400 MHz, DMSO-d6) δ (ppm): 10.19 (s, 1H), 6.75 (d, J=8.0 Hz, 1), 6.69 (s, 2H), 6.61 (d, J=8.0 Hz, 1H), 5.43 (d, J=10.0 Hz, 1H), 5.41 (d, 14.4 Hz, 1H), 4.30-4.20 (m, 4H), 3.80 (s, 6H), 2.21-2.15 (m, 1H), 2.01 (s, 3H), 1.81 (m, 1H), 1.76-1.64 (m, 1H), 1.06 (s, 9H), 1.00 (s, 9H), 0.70 (t, J=7.6 Hz, 3H).

Source