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Energy saving and environment protection are two important issues that today’s automobile industry must emphasize. Lots of heat energy waste with the exhaust gas when the engine is running. If this part of waste heat can be recovered, the energy efficiency will be improved. Thus plenty of energy can be saved and the global warming also can be reduced. In this paper, the organic Rankine cycle whose working fluid was R245fa was studied. It was adopted to recover the gasoline engine waste heat. The mathematical model of the organic Rankine cycle was built up in Matlab to search the optimized working condition. The pinch analysis method was used to analyze the outlet temperature of the exhaust gas. The results indicate that organic Rankine cycle is a good way to recover the gasoline engine waste heat, especially in the high load conditions. The temperature of the exhaust gas can be apparently decreased.

New nucleoside analogues 14−17 based on a methylenecyclopropane structure were synthesized and evaluated for antiviral activity. Reaction of 2,3-dibromopropene (19) with adenine (18) led to bromoalkene 20, which was benzoylated to give N⁶,N⁶-dibenzoyl derivative 23. Attempts to convert 20 or 23 to bromocyclopropanes 21 and 22 by reaction with ethyl diazoacetate catalyzed by Rh2(OAc)4 were futile. By contrast, 2,3-dibromopropene (19) afforded smoothly (E)- and (Z)-dibromocyclopropane carboxylic esters 24 + 25. Alkylation of adenine (18) with 24 + 25 gave (E)- and (Z)-bromo derivatives 21 + 22. Base-catalyzed elimination of HBr resulted in the formation of (Z)- and (E)-methylenecyclopropanecarboxylic esters 26 + 27. More convenient one-pot alkylation−elimination of adenine (18) or 2-amino-6-chloropurine (30) with 24 + 25 afforded (Z)- and (E)-methylenecyclopropane derivatives 26 + 27 and 31 + 32. The Z-isomers were always predominant in these mixtures (Z/E ~ 2/1). Reduction of 26 + 27 and 31 + 32 with DIBALH afforded (Z)- and (E)-methylenecyclopropane alcohols 14 + 16 and 33 + 34. The latter were resolved directly by chromatography. Compounds 14 + 16 were converted to N⁶-(dimethylamino)methylene derivatives 28 and 29 which were separated and deprotected to give 14 and 16. Reaction of 33 and 34 with HCO2H led to guanine analogues 15 and 17. The ¹H NMR spectra of the Z-analogues 14 and 15 are consistent with an anti-like conformation of the nucleobases. By contrast, ¹H NMR and IR spectra of bromo ester 21 are indicative of syn-conformation of adenine. Several Z-(hydroxymethyl)methylenecyclopropanes exhibited in vitro antiviral activity in micromolar or submicromolar range against human and murine cytomegalovirus (HCMV and MCMV), Epstein−Barr virus (EBV), human herpes virus 6 (HHV-6), varicella zoster virus (VZV), and hepatitis B virus (HBV). Analogues 14, 15, and 33 were the most effective agents against HCMV (IC50 1−2.1, 0.04−2.1, and 0.8−5.6 μM), MCMV (IC50 2.1, 0.3, and 0.3 μM) and EBV in H-1 (IC50 0.2, 0.3, and 0.7 μM) and Daudi cells (IC50 3.2, 5.6, and 1.2 μM). Adenine analogue 14 was active against HBV (IC50 2 μM), VZV (IC50 2.5 μM), and HHV-6 (IC50 14 μM). Synadenol (14) and the E-isomer (16) were substrates of moderate efficiency for adenosine deaminase from calf intestine. The E-isomer 16 was more reactive than Z-isomer 14. The deamination of 14 effectively stopped at 50% conversion. Synadenol (14) was also deaminated by AMP deaminase from aspergillus sp.