Synthesis
The general procedure for the synthesis of (R)-1-bromo-3,7-dimethyloctane from 3,7-dimethyloctan-1-ol was as follows: concentrated sulfuric acid (17 mL) was slowly added to 48% hydrobromic acid (100 mL) under stirring conditions, followed by 3,7-dimethyloctan-1-ol (67 mL, 100 g). The reaction mixture was heated to 120-125 °C and maintained at this temperature for 3 hours. After completion of the reaction, the mixture was cooled and extracted with heptane (300 mL). The heptane layer was washed sequentially with dilute hydrochloric acid, water and sodium bicarbonate solution and concentrated after drying to give 81.5 g of oily crude product. This crude product was subjected to vacuum distillation at a bath temperature of 120-125 °C, and the fraction with a boiling point of 85-87 °C/10 mmHg was collected to afford the target product (R)-1-bromo-3,7-dimethyloctane in the form of colorless oil in a yield of 78.2 g in 100% yield. Mass spectrometry analysis showed molecular ion peaks m/z 220,222 (M+).
References
[1] Patent: US8471035, 2013, B1. Location in patent: Page/Page column 9; 10
[2] Patent: US2018/273524, 2018, A1. Location in patent: Paragraph 0044
[3] Patent: EP2816053, 2014, A1. Location in patent: Paragraph 0352
[4] Patent: US9371353, 2016, B2. Location in patent: Page/Page column 73; 74; 75
[5] Helvetica Chimica Acta, 1981, vol. 64, # 4, p. 1158 - 1173
