Materials
High-purity chemicals were purchased from Rankem, Avra and Sigma Aldrich. All materials were of commercial reagent grade.
Apparatus
The IR spectra were recorded on Shimadzu FTIR-8400S spectrometer. The 1H NMR and 13C NMR spectra were run on a Bruker spectrophotometer at 400 MHz and 125 MHz respectively. The elemental (C, H, and N) analyses were measured on Perkin-Elmer 2400. HPLC system (1100 series Agilent technologies, 76337 Waldbronn, Germany) equipped with quaternary pump, auto injector with photodiode array detector (PDA) was used.
General procedure for synthesis of 3
To a clean and dry stainless steel Reactor, (10,11)-didehydro-11-deoxy-6-O-methyl-2’,4’’-O-bis-(triethylsilyl)-12-O-chloroacetyl-(10E)-erythromycin A (2) (4.0 Kg, 3.86 mol) and DMF (20 L) was added at 25-30°C under nitrogen atmosphere. This reaction mixture was treated with Cesium carbonate (1.52 Kg, 4.66 mol), trimethylsilyl cyanide (1.16 Kg, 11.69 mol) followed by addition of methanol (0.37 Kg, 11.62 mol) at 25°C to 45°C for 3.0 h. After monitoring of reaction by HPLC, the reaction mixture was cooled to 25-30°C. The product was isolated after addition of water (20 L.). Centrifuge and wet cake washed with water (16 L) and then dried at 60°C under vacuum for 8 h get compound 3.
White solid, Yield: 3.77 Kg, 95 %. IR (KBr)/γ (cm‐1): 2877.96, 2243.70, 1796.82, 1739.57, 1698.50, 1158.66; 1H NMR (CDCl3, 400 MHz)/δ ppm: 0.58-0.65-1.49 (m, 12H), 0.92-0.98 (m, 18H), 1.03-1.09 (m, 9H), 1.14-1.17 (m, 6H), 1.20-1.24 (m, 6H), 1.35 (s, 3H), 1.47-1.51 (dd, 2H), 1.52 (s, 3H), 1.58-1.60 (m, 2H), 1.68-1.74 (m, 2H), 1.79-1.85 (m, 2H), 2.18 (s, 6H), 2.28-2.31 (d, 1H), 2.43-2.48 (m, 1H), 2.56-2.60 (m, 1H), 2.82-2.88 (t, 1H), 3.00-3.04 (dd, 1H), 3.08 (s, 3H), 3.12-3.15 (m, 2H), 3.19-3.21 (d, 1H), 3.31 (s, 3H), 3.63-3.67 (m, 2H), 3.86-3.88 ( d, 1H), 4.13-4.19 (m, 1H), 4.48-4.50 (d, 2H), 4.71 (s, 1H), 4.88-4.89 (d, 1H), 5.23-5.26 (dd, 1H); 13C NMR (CDCl3, 400 MHz)/δ ppm: 7.2, 10.0, 10.5, 14.4, 14.9, 16.1, 18.3, 19.4, 20.4, 22.2, 22.2, 22.4, 29.5, 32.8, 34.1, 35.9, 39.4, 40.3, 41.1, 44.6, 45.1, 45.8, 50.5, 65.6, 65.7, 67.1, 73.3, 73.4, 76.2, 76.8, 77.1, 77.5, 79.0, 79.2, 80.8, 89.3, 95.7, 102.7, 115.7, 168.4, 176.2, 216.9; CHN. For C53H96N2O13Si2: C= 62.07; H= 9.44; N= 2.73; found: C= 61.84; H= 9.53; N= 2.62; ES-MS: 1026.1 as (M+1); HPLC Purity: 98.97 %; SOR [α] 22/D: -86.599 to -89.774°, (c = 1 in DCM.)